Thermoplastic cellulose esters are promising materials for bioplastic packaging. For that usage, it is important to understand their mechanical and surface wettability properties. In this study, a series of cellulose esters are prepared, such as laurate, myristate, palmitate, and stearate. The aim of the study is to investigate the tensile and surface wettability properties of the synthesized cellulose fatty acid esters to understand their suitability as a bioplastic packaging material. Cellulose fatty acid esters are first synthesized from microcrystalline cellulose (MCC), then dissolved in pyridine solution, and after the solvent cast into thin films. The cellulose fatty acid ester acylation process is characterized by the FTIR method. Cellulose esters hydrophobicity is evaluated with contact angle measurements. The mechanical properties of the films are tested with the tensile test. For all the synthesized films, FTIR provides clear evidence of acylation by showing the presence of characteristic peaks. Films’ mechanical properties are comparable to those of generally used plastics such as LDPE and HDPE. Furthermore, it appears that with an increase in the side-chain length, the water barrier properties showed improvement. These results show that they could potentially be suitable materials for films and packaging materials. In recent years the demand for bio-derived resources because of overriding environmental contamination and diminishing fossil reserves worldwide has been brought to attention . At pres9 tons of biomass, of which cellulose is 35–50%. This concludes that cellulose is the most abundant biopolymer. It is possible to chemically modify it, and the synthesis of cellulose esters allows for obtaining the needed strength and biodegradability and enables the use of cellulose for various applications. However, cellulose’s hydrophilicity, dense fibrous structure, and insolubility in traditional solvents are restricting its full potential for usage  of cellulose solution in cupriethylenediamine hydroxide, CuEn, according to a standard procedure ASTM D1795-13. The MM was then calculated by the Mark-Houwink equation with parameters K = 1.01 × 10−4 dL/g and a = 0.9 [OAc] and stirred at 60 °C for several hours until the cellulose was completely dissolved to yield a 3.5 wt% solution. To decrease the viscosity, which simplifies the processing, a co-solvent DMSO was added in a ratio of 1:1 to IL. The designed amount of the respective vinyl ester (3 eq./AGU) was added to the cellulose solution in a chemical reactor equipped with a mechanical stirrer and nitrogen flow, and then the reaction was performed at the conditions shown in 1H NMR (hydrogen-1 nuclear magnetic resonance) and 13C NMR (carbon nuclear magnetic resonance) methods. The 1H NMR and 13C NMR spectra of the cellulose fatty acid esters were acquired on an Agilent Technologies DD2 500 MHz spectrometer equipped with 5 mm broadband inverse (1H) or broadband observe (13C spectra) probes. In addition, a 15 min temperature equilibration delay was allowed between sample insertion and NMR acquisition at 40 °C  or 80 °C (cellulose laurate in DMSO-d6 and cellulose myristate and laurate in Py-d5) sample temperatures. Typically, for 1H spectra, 32 scans with a 25 s relaxation delay were acquired, and for 13C, 20,000–45,000 scans with a 2.5 s recycle delay were acquired to achieve the desired signal-to-noise ratio.DS values were determined with 1H NMR and 13C NMR. In the 1H NMR spectrum, the proton signals from approximately 6.00 to 3.50 ppm are assigned to protons of AGU in cellulose. The signals at 2.32–1.93, 1.88–1.45, and 1.27 ppm are associated with the methylene protons. The signals at 0.98–0.79 ppm are attributed to the methyl protons.The chemical structures of the cellulose esters were confirmed by 13C NMR spectrum of cellulose esters, the signals from 34.78 to 23.34 are assigned to carbons of the aliphatic fatty acid chain, and 14.60 ppm is assigned to the carbon of the ending methyl group of the aliphatic side chain. The AGU carbons C-1, C-1′, C-4, C-2,3,5, C-6, and C-6′ give signals at 104.98, 102.33, 81.50, 76.91–74.35, 64.32, and 62.68 ppm, respectively. The signals from 173.89 to 170.98 ppm correspond to the carbonyl carbon at C-7, which provides direct confirmation of the successful attachment of the long-chain fatty acid chain to the cellulose backbone.In the 1H NMR spectrum by taking an integral of the area of terminal methyl groups (ICH3) and AGU signals (IAGU) based on the reported method [The DS of cellulose laurate, -myristate, -palmitate, and -stearate was calculated with equation 1 from the d method . The cal−1 . Solutions were then solvent casted on laminated glass plates (250 mm × 150 mm) using the film casting knife  with a blade width of 100 mm. With the given knife, the casted thickness of 200 μm was set to achieve the final film thickness of 70–100 μm. Except for cellulose diacetate, in which a casting thickness of 100 μm was set due to a higher cellulose concentration. Subsequently, the films were dried for 24 h in the open air under a fume at a room temperature of 20 °C. The films were removed using a phase immersion method in water after the solutions had been set on the glass plates. Additionally, the pH of the film’s surface was determined with the flat electrode using the Mettler Toledo SevenCompact pH meter S210  to check the acidic levels of each synthesized film. All measurements were conducted at a room temperature of 23 °C and an air humidity of 40%. Cellulose esters were dissolved in pyridine, and the obtained solutions shear rate ranged from 0.001 to 100 s−1. Four scans were taken from each sample with a resolution of 8 cm−1 in absorbance mode. For comparison, all spectra were adjusted to the same baseline.The FTIR spectroscopy analysis was carried out on native cellulose and synthesized cellulose esters to evaluate the acylation process. Measurements were performed on an Interspectrum FTIR spectrometer  with the KBr disc method between 500 and 4000 cmThe surface hydrophobicity of the prepared films was estimated by measuring parameters such as equilibrium contact angle. The sessile drop method was used to measure contact angles with the device DataPhysics OCA 20 and the SCA 20 software . All measurements were performed on the top side of the films with distilled water as a liquid agent to create a drop on the surface. The total observation time of the contact angle changing was 40 s starting from the moment when the water drop came into contact with the measured surface. An average of each point of measurement  was taken. A total of six measurements were taken for each variable, and the material average was taken from these six measurements. Before the measurement, the specimens were fixed with clamps on the measuring plate to achieve a smooth surface. All measurements of the contact angle were performed at room temperature and a relative humidity of 40%. p-value was significant, the Bonferroni correction with the new alpha was utilized by dividing the alpha by the given comparisons (t-tests). The new alpha was set at 0.005 (10 comparisons).The tensile test was performed according to ISO 527-3 . The sta−1, 2849 cm−1, and 1467 cm−1 identify the presence of fatty acid long chains and correspond to anti-symmetric C−H stretching, symmetric C−H stretching, and C−H bending vibrations of the cellulose stearate, palmitate, myristate, and laurate [−1 (C=O), 1225 cm−1 (−C−O− stretching), and 716 cm−1  [−1 (OH stretching) is observed for all the synthesized fatty acid esters compared to the native microcrystalline cellulose. laurate . In the  groups) . These b groups) ,17,24,25p < 0.05) compared to fatty acid cellulose esters , which correlates with the observation of chain length increase. Thus, this research shows that all the synthesized cellulose fatty acid esters have the desired hydrophobic properties (contact angle >90°) for the use of food packaging materials.In general, cellulose esters should be more hydrophobic than cellulose due to acetylation . HoweverTensile properties of the casted films were observed to evaluate the effect of side chain length on cellulose fatty acid esters strength, elongation, and elastic properties. From our study results , it is sWhen compared to the commercially available cellulose acetate, the long sidechains of cellulose esters give a significant decrease in elastic modulus (~70–80%), tensile strength (~60–70%), and an increase in strain at break (~700–1200%). This data indicates that the fatty acids in the cellulose esters could already function as an internal plasticizer. According to Crépy and Wen ,16, whenOur research data show some similarities to those of commercial polymers (low-density polyethylene and high-density polyethylene). According to Crépy , LDPE haNew cellulose esters  were successfully synthesized in ionic liquid and solvent casted into films. Their surface and mechanical properties were evaluated and compared with those of commercial cellulose diacetate. A lower degree of substitution (<1) results in an increase in stiffness and strength ), which is more like the highly substituted cellulose acetate. However, with the effect of long aliphatic chains, the material obtains a higher strain than commercially used cellulose acetate, which is satisfactory for packaging material. All the synthesised cellulose fatty acid esters showed the desired hydrophobic properties for the food packaging materials. With the increase in side-chain length, the water barrier properties improved. Cellulose palmitate (C16) and cellulose stearate (C18) casted films showed the highest hydrophobic properties. When compared to commercial cellulose acetate (C2), the synthesised cellulose esters had increased elongation and hydrophobicity. Cellulose laurate (C12) and cellulose palmitate (C16) are most similar to LDPE and HDPE, respectively. According to our research data, it is promising that the fatty acid cellulose esters could be utilized for future bioplastic applications.


Growing concerns about environmental issues and global warming have garnered increased attention in recent decades. Consequently, the use of materials sourced from renewable and biodegradable origins, produced sustainably, has piqued the interest of scientific researchers. Biodegradable and naturally derived polymers, such as cellulose and polylactic acid (PLA), have consistently been the focus of scientific investigation. The objective is to develop novel materials that could potentially replace conventional petroleum-based polymers, offering specific properties tailored for diverse applications while upholding principles of sustainability and technology as well as economic viability. Against this backdrop, the aim of this review is to provide a comprehensive overview of recent advancements in research concerning the use of polylactic acid (PLA) and the incorporation of cellulose as a reinforcing agent within this polymeric matrix, alongside the application of 3D printing technology. Additionally, a pivotal additive in the combination of PLA and cellulose, polyethylene glycol (PEG), is explored. A systematic review of the existing literature related to the combination of these materials  and 3D printing was conducted using the Web of Science and Scopus databases. The outcomes of this search are presented through a comparative analysis of diverse studies, encompassing aspects such as the scale and cellulose amount added into the PLA matrix, modifications applied to cellulose surfaces, the incorporation of additives or compatibilizing agents, variations in molecular weight and in the quantity of PEG introduced into the PLA/cellulose (nano)composites, and the resulting impact of these variables on the properties of these materials. Polylactide, also known as poly(lactic acid) (PLA), stands as a biopolymer derived from renewable and biodegradable sources. It boasts remarkable mechanical characteristics, including a notable ultimate tensile strength ranging from 50 to 70 MPa and a tensile modulus of around 3 GPa ,2,3. TheTo overcome these disadvantages, recent research has investigated the use of cellulose to improve the mechanical, thermal, and rheological properties of PLA ,7,8,9,10The use of cellulose as a natural reinforcement for PLA has been widely studied, as it provides the PLA matrix with better mechanical and rheological properties as well as high crystallinity, which depends on the combination of different factors, such as the mixing processes used and the properties of the cellulose , and the use of compatibilizing agents, surfactants and plasticizers ,5,7. ComWhen producing PLA composites with cellulose, it is common to incorporate additives that enhance material compatibility and modify melt viscosity. This is particularly important as introducing reinforcement, depending on its scale and quantity, has the potential to elevate viscosity, thereby potentially impeding the efficiency of manufacturing processes. One of the most used additives for this type of composite is polyethylene glycol (PEG), which, depending on the molecular weight, can act both as a compatibilizing agent and as a plasticizer . In addiRegarding the methods used in the preparation of PLA/cellulose composites and nanocomposites, the most common are melt mixing  ,14,15,16Additive manufacturing (AM) techniques, which include fused filament fabrication (FFF), are gaining prominence in recent years because they have advantages such as precise control of complex structures, the ability to use various types of plastic materials, and little waste in the process .Hence, this review provides a comprehensive analysis of the existing literature pertaining to the utilization of cellulose in various scales, concentrations, and forms to reinforce the biodegradable PLA matrix. It also explored the impact of incorporating PEG as an additive and examined the application of these composite materials in filament production for 3D printing. Furthermore, this review systematically addresses the array of studies within the literature encompassing the following themes: cellulose-reinforced PLA composites, the role of PEG as an additive to enhance and modify composite properties, the expansion of processing possibilities and potential applications, and the utilization of PLA/cellulose/PEG (nano)composites for filament fabrication in the realm of 3D printing.Biopolymers are defined as sustainable polymers produced from a variety of renewable raw materials such as polysaccharides, lignin, vegetable oils, pine resin derivatives, and proteins as a substitute for petroleum, the most conventional fossil resource ,27. ThisThe biopolymer market has experienced growth in recent years, encompassing both biodegradable and non-biodegradable variants derived from renewable and non-renewable sources. This expansion is attributed to the increasing demand from consumer goods companies, who are striving to offer environmentally friendly products in alignment with sustainability standards ,32.According to the European Bioplastic Report , the totDespite the promising growth, the production of bioplastics still represents less than 1% of the more than 390 million tons of plastic produced annually. This limitation persists due to factors such as the elevated production expenses, insufficient political incentives, and inherent properties that frequently hinder their compatibility with certain applications across various sectors ,32. Among the currently most used biopolymers, PLA stands out for being obtained from a renewable source and presenting biodegradability in industrial composting environments . PLA is Due to the chirality of the lactic acid monomer, PLA exists in different enantiomeric forms , and its properties depend both on the content of optical impurities among the enantiomers and the molecular weight . PolymerThe main applications of PLA are in the production of plastic films, recyclable and biodegradable packaging , garbage bags, wall coverings, fabrics, fibers, and biodegradable medical devices , textile fibers, and 3D printing filaments . Although it has lower toughness; less than 10% elongation compared to conventional polyolefins such as PP, for example; and a low crystallization rate, these properties can be improved with the addition of different filler particles, including cellulose at micro- and nanoscales, which, in addition to improving the thermomechanical properties, do not affect the biodegradability of the polymer ,39,40,41Regarding its application as a filament in additive manufacturing, PLA offers several advantages outlined in Nonetheless, certain limitations, also listed in In polymer composites with a PLA matrix, the cellulose used as filler or reinforcement is added in different amounts, shapes, and scales, such as cellulose fibers ,43,44,45Cellulose can be derived from diverse natural sources like sugarcane bagasse ,45, flaxCellulose fibers are defined as a set of microfibrils where the cellulose molecules are stabilized laterally through hydrogen bonds between the hydroxyl groups . In the The isolation of cellulose nanofibers from lignocellulosic fibers can be performed via different processes, such as electrospinning ,63,64,65Distinct morphologies are achieved contingent on the technique employed to fragment macroscopic fibers into nanofibers. Through acid hydrolysis, a colloidal suspension of aggregates characterized by high crystallinity and an elevated aspect ratio is formed, referred to as microcrystalline cellulose (MCC). Subsequent to acid hydrolysis, the application of sonification disintegrates the fibril aggregates, yielding cellulose whiskers, also recognized as nanocrystalline cellulose (NCC). Utilizing multiple mechanical shearing actions yields microfibrillated cellulose (MFC) or nanofibrillated cellulose (CNF), both comprising interconnected fibrils and fibril aggregates. Additionally, MFC can be obtained through pretreatment involving enzymatic hydrolysis coupled with mechanical shearing .Regardless of the cellulose scale used, there is a chemical incompatibility between hydrophilic cellulose and most hydrophobic thermoplastic polymer matrices. Thus, to improve the compatibility between cellulose and the PLA matrix, surface treatments are often used, which can be chemical, physical, or enzymatic and whose primary function is to increase the hydrophobicity of the cellulose surface, removing some amorphous constituents from lignocellulosic sources or adding some functional group that increases the hydrophobicity of the fiber and improves the chemical and mechanical compatibility with the polymeric matrix. It is also possible to graft polymers on a cellulose surface, decreasing the surface energy and increasing compatibility between cellulose and a polymer matrix .The use of nanocellulose as a natural reinforcement for PLA has been widely studied, as it provides the PLA matrix with better mechanical and rheological properties, which depend on the combination of different factors, such as the mixing processes used and the properties of the cellulose , as well as the use of compatibilizing agents and surfactants ,7. CombiThe use of plasticizers is one of the effective methods to change the properties of polymers and thus increase the variety of applications. PLA is a rigid polymer, which limits its use in many applications, and in this way the use of plasticizers improves the mechanical properties and also helps in the fluidity of the polymeric matrix during processing . PlasticAmong the various plasticizers used for PLA, notable choices include citrate esters, poly(ethylene glycol) (PEG), glycerol, oligomeric lactic acid, and glucose monoesters. PEG, particularly when possessing low molecular weight, distinguishes itself due to its exceptional miscibility, biodegradability, and suitability for applications involving food contact ,12.2CH2)nOH. It is available in a broad range of molecular weights, spanning from 100 to 6000 g/mol [PEG is a nonionic, water-soluble polymer, characterized by the general formula H concentration could maintain stability for four months, after which considerable parameter shifts occurred. Notably, an increased concentration of PEG400, specifically 20% (w/w), extended shellac stability for 6 months.Luangtana-Anan et al.  studied Li et al., 2020  studied In Industry 4.0, 3D printing manufacturing technology, an additive manufacturing technique, also known as layered deposition or rapid prototyping, is a process for manufacturing three-dimensional (3D) objects through the deposition of material in layers, capable of producing parts with complex and customized ergonomic shapes ,76. WithThe thermoplastics most used in this type of additive manufacturing are ABS and PLA, and PLA is more sustainable since it is derived from natural sources and is biodegradable in an industrial composting environment. Furthermore, parts produced by 3D printing using the FFF technique with PLA have fewer warping problems and better mechanical properties compared to ABS . ConversDespite the numerous papers published in this area, much development still needs to be carried out since problems of cellulose agglomeration, the lack of compatibility with the polymeric matrix, and the heterogeneity of the cellulose dispersion within the matrix, as previously mentioned, minimize the capacity of the cellulose to improve the mechanical and rheological properties of PLA while also affecting the printability of the polymer, inducing processing problems, color change, and carbonization .The primary aim of this study is to explore and comprehend the pivotal role of PEG in enhancing the properties of PLA/cellulose (nano)composites when employed in the fabrication of filaments intended for 3D printing. A comprehensive analysis is sought on how the incorporation of PEG affects the mechanical, thermal, and rheological characteristics of these composites, as well as their overall performance as raw materials in additive manufacturing. To evaluate the state of the art in this subject, a bibliometric analysis was carried out of published articles that contained some specific keywords within this theme.A systematic literature search was conducted in the Scopus and Web of Science (WOS) databases, considering English-language documents, and excluding conference papers, reviews, and book chapters. Four distinct searches were carried out using the keywords outlined in The primary function of this systematic review article is to comprehensively investigate and analyze the effects of incorporating PEG into cellulose-reinforced PLA (nano)composites, particularly in the context of filament production for 3D printing. The review critically evaluates the existing literature to understand how different characteristics of PEG, such as molecular weight, percentage added, and the type of cellulose used, influence the mechanical, thermal, and rheological properties of these composites. Additionally, it seeks to identify trends and usage patterns of PEG in these composites by synthesizing findings from a range of studies. The review also highlights research gaps, indicating areas that require further investigation.Furthermore, the article serves as a decision-support tool for optimizing PLA/cellulose composite formulations for 3D printing by providing valuable insights based on a systematic analysis of the literature.This review is intended to provide an informative synthesis of the existing literature, aiming to offer insights and understanding rather than making prescriptive recommendations. Its primary purpose is to comprehensively analyze and distill the available knowledge, facilitating a deeper understanding of PLA/cellulose composites with PEG in 3D printing, without prescribing specific actions or outcomes.The initial search (Search 0) considered general terms, resulting in 1346 documents spanning the past 45 years. Subsequently, the inclusion of the term “PEG” (Search 1) notably reduced the pool to 51 documents published within the last seventeen years. With the incorporation of the term “3D printing” (Search 2), the search yielded 45 documents, all of which are notably recent, originating from 2017 onwards. Finally, the most recent search (Search 3) combined “PEG” and “3D printing”, culminating in the discovery of only two documents published in the last seven years. This clearly underscores a research gap in the literature, presenting a significant opportunity for future research.Regarding Searches 1 and 2, Furthermore, Keyword networking was realized using VOSviewer software (version 1.6.16) considering the frequency and chronological time  with a mAmong the 51 research papers published in the literature using the keywords specified in Search 1 ((“PLA” OR “polylactic acid” OR “poly(lactic acid)” OR “poly(lactide)” AND “cellulose” AND “PEG”), as detailed in Publications with cellulose fibers (or micrometric fibers) reported the use of filler ranging from 15 wt.% to 25 wt.%, while the amount of PEG reported in these papers was between 0.5% to 40%. Moscoso-Sánchez et al.  used 15 The use of MCC was reported by Jirum and Baimark , Moreno Wang et al.  also notPEG was added in these papers in the range from 5 to 20%, and the molecular weights were 400 g/mol ,85, 600 Most of the research papers therefore used nanocellulose as a reinforcement, both NCC and CNF. Only one publication reported the use of cellulose nanosphere (CNS) . With thThe use of PEG as a coupling agent to change the surface properties of cellulose and increase the compatibility with PLA was reported by Macke et al. , Yu et aSrisawat et al.  comparedEicher et al.  reportedIn general, higher plasticizer molecular weights are associated with increased resistance to migration, prolonged utility lifespan, and reduced volatilization. Nevertheless, based on the results published in the literature for PLA/cellulose composites and nanocomposites, PEG can act as a plasticizer, its most common use. Additionally, PEG serves as a compatibilizer between hydrophilic cellulose and hydrophobic PLA. Thus, the effect of PEG addition can vary according to its molecular weight, the added content, as well as the specific type and scale of cellulose employed as a filler or reinforcement.The primary manufacturing processes reported in the publications arising from Search 1, for composites reinforced with fibers and MCC or MFC, were the combination of mixing processes such as melting blending using an internal mixer or twin-screw extruder, with molding processes such as solvent casting, compression, extrusion, and injection . For nanIn the systematic examination of the literature using the terms specified in Search 2 ((PLA” OR “polylactic acid” OR “poly (lactic acid)” OR “poly(lactide)” AND “cellulose” AND “3D printing”), a total of 45 published papers were identified , 18% involve MCC or MFC, and another 18% incorporate cellulose fibers sourced from various natural origins (as depicted in 2SO4-SE-steam explosion). Their evaluation encompassed both the potential for ethanol production and the enhancement of economic viability in the reed biorefinery process. The outcomes of this analysis led to the identification of three specific pretreatment processes: RES (enzyme hydrolysis-processing residue treated with NaOH), REP (enzyme hydrolysis-processing residue treated with p-TsOH), and RED (enzyme hydrolysis-processing residue treated with H2SO4-SE). Subsequently, these treated residues were harnessed as the reinforcing phase for the material utilized in 3D printing.Within the subset of eight publications that explored cellulose at the micrometric scale (cellulose fibers), the content of fibers integrated into the PLA matrix spanned from 3 to 30 wt.%. Notably, merely two of these publications documented the implementation of surface modifications to the fibers. Jiang et al.  documentIt is worth mentioning that two other publications, related to the keywords of Search 2 and using cellulose fibers as a filler, were identified in the literature, although they did not appear in the searches carried out in the databases used, probably because they did not contain the exact keywords used in this search. In these two publications, the authors also used surface treatment of the cellulose fiber, such as treatment with tetraethyl orthosilicate (TEOS) to increase the compatibility between PLA and the fiber  and chemThe application of PEG was documented by Ma et al. , who incIn terms of employing MCC or MFC, the database search yielded eight publications. Within this set, seven studies employed MCC, with only one publication opting for MFC. Winter et al.  presenteThe amount of MCC and MFC reported in these works varied from 1 wt.% to 50 wt.%, and the use of a superficial modification of cellulose was reported by Murphy et al. . Murphy From Search 2, 20 documents related to the use of nanocellulose as a filler to PLA matrix. Besides NCC and CNF, the use of carbonized cellulose nanofibers  and TEMPThe effect of NCC or CNF addition on the PLA matrix, however, depends on different factors such as amount of filler added and the use of a coupling agent or some cellulose surface modification. According to Dong et al. , the incAmong the papers resulting from Search 2, not all reported studies considered the 3D printing process; some publications reported only filament production, using in most cases a twin-screw extruder . In someAs in Search 1, some papers resulting from Search 2 did not necessarily report the production of PLA/cellulose composites or nanocomposites but rather the formation of blends and/or the use of cellulose derivatives. Pis et al. , for exaFinally, from Search 3 (“PLA” OR “polylactic acid” OR “poly(lactic acid)” OR “poly(lactide)” AND “cellulose” AND “PEG” AND “3D printing”), only two research papers were identified. These two works are from the same authors, in which they discussed the use of PLA with NCC concerning the printability of the composite plasticized with PEG  and alsoIn the realm of PLA/cellulose (nano)composites and 3D printing, there are numerous promising avenues for future exploration and research.Firstly, the potential of cellulose in these composites can be further unlocked by varying its scale, content, and sourcing from different natural origins. By tailoring the type and source of cellulose, researchers can fine-tune the composite properties, adapting them to specific applications. Furthermore, there is a critical need to delve deeper into understanding how different molecular weights of polyethylene glycol (PEG) influence PLA/cellulose (nano)composites. This investigation is essential for optimizing composite properties and ensuring they meet desired performance criteria.In the context of 3D printing, one intriguing prospect is addressing the challenges associated with multiple extrusion cycles, a common practice for achieving better composite uniformity. Given PLA’s sensitivity to temperature and potential degradation, exploring the effects of multiple extrusion cycles is vital to preserving material integrity. The rapidly evolving landscape of 3D printing, as an emerging manufacturing technology, necessitates increased attention and diversified research. This entails exploring innovative approaches, materials, and processes, particularly within the realm of composites.Environmental considerations are becoming increasingly important. Future research should encompass comprehensive assessments of the environmental impact of PLA/cellulose composite filaments and the final printed products. Sustainability, carbon footprint, and eco-friendliness throughout their lifecycle should be thoroughly evaluated. Understanding the end-of-life implications of PLA/cellulose (nano)composites is equally crucial. This includes studying the disposal and recyclability aspects to ensure these materials align with sustainable practices and do not contribute to environmental harm.Lastly, evaluating the residue generated during filament production and 3D printing processes is vital. Effective waste management strategies should be developed to minimize environmental impact and maximize resource utilization.In summary, the prospects for future research in the field of PLA/cellulose (nano)composites and 3D printing are expansive, encompassing various opportunities from material composition enhancement to sustainable practices and environmental impact assessment. Addressing these prospects will drive progress in the field, optimizing composite performance and promoting sustainability in 3D printing. Future research should also focus on the environmental impact of the PLA/cellulose composite filaments and final printed products, as well as their end of life. Also, the residue generated throughout the filament and printing process should be evaluated.The versatility of PLA/cellulose (nano)composites, particularly when enhanced with additives like polyethylene glycol (PEG), extends to a wide array of industries and uses. In the realm of packaging, these composites offer an eco-friendly alternative. They can be employed for biodegradable packaging solutions, including food packaging ,150,151,In the biomedical field, the biocompatibility of these (nano)composites makes them suitable for creating biodegradable medical devices. They have applications in biodegradable implants, drug delivery systems, and tissue scaffolds for regenerative medicine ,153,154.In the realm of 3D printing, neat PLA is already widely employed for producing biodegradable and environmentally friendly 3D-printed objects. This includes a wide range of items from prototypes to functional parts and artistic creations. However, when combined with cellulose as a reinforcement, the literature predominantly focuses on material characterization and filament production, with limited reporting on specific practical applications. Nevertheless, the PLA/cellulose (nano)composite shows significant promise for 3D printing applications, especially when incorporating additives like PEG. These additives enhance the composite’s rheological, mechanical, and thermal properties, making it an attractive candidate for a wide range of 3D printing applications ,142,143.In summary, PLA/cellulose (nano)composites have some other less common yet promising applications including textiles, automotive, agriculture, consumer goods, and construction. These applications offer sustainable solutions and align with environmental responsibility. Ongoing research is expected to reveal more innovative uses in the future.This review covered the main concerns on PLA/cellulose/PEG composites. Firstly, an overview of each material was given, emphasizing its recent trends. Then, a systematic review was provided according to the most current databases in the field (Scopus and Web of Science), in which three searches were highlighted and discussed over the work.Cellulose, as a valuable compound from natural sources, has been widely applied in the PLA composites field with articles published in the past 45 years (848 documents), while the use of PEG (Search 1) and the composite’s application in 3D printing (Search 2) are recent subjects. Regarding the 3D printing topic, Search 2 presented 39 documents, with an increasing tendency in the last 6 years, emphasizing that this subject should be explored more in future works, focusing on improving the PLA/cellulose filaments’ performance in printing. Also, Search 3 showed that the use of PEG to improve the 3D printability of PLA/cellulose composite represents a significant gap in the literature as well as the use of other plasticizer/coupling agents.The discussion of the articles resulting from Searches 1 and 2 provided significant information about the scales/content of cellulose that have been used, the principal properties of the composites, and possibilities for improvement by using a plasticizer with different molecular weight. Also, printing parameters and performance were widely reported. Therefore, this work not only provided valuable information to guide future studies but also emphasized 3D printing as an innovative feature for PLA reinforced with natural filler composites, showing that there is much more than the commonly used PLA filament.


In the last few years, new sustainable fractionation processes have been developed that enable the obtaining of cellulose fibers in a more eco-friendly way. As a raw material, cellulose’s use is widely known and established in many areas. Additionally, its products/derivatives are recognized to have a far better environmental impact than fossil-based materials. Examples are textiles and packaging, where forest-based fibers may contribute to renewable and biodegradable substitutes for common synthetic materials and plastics. In this review, some of the main structural characteristics and properties of cellulose, recent green extraction methods/strategies, chemical modification, and applications of cellulose derivatives are discussed.Cellulose is the most abundant renewable polymer on Earth and can be obtained from several different sources, such as trees, grass, or biomass residues. However, one of the issues is that not all the fractionation processes are eco-friendly and are essentially based on cooking the lignocellulose feedstock in a harsh chemical mixture, such as NaOH + Na The rapid population growth and rise of globalization have been followed by the depletion of fossil fuel reserves, increasing health/environmental concerns. These have led researchers worldwide to look for new renewable resources for a more sustainable future. Cellulose, as the main component of plants , is the most abundant biopolymer on earth. Due to its high availability, low cost , biodegradability, appealing physical properties, and chemical reactivity , cellulose has been receiving great attention from the research community over the last decades. Recent renewed interest has arisen due to its potential use as a renewable energy platform and for the development of cellulose-based materials.2 [A crucial contribution to the global climate challenge comes from forests and forest-based products, which store ca. 447 million tons of CO2 . In fact2 . For exa2 .However, cellulose processing is challenging due to some important disadvantages, such as its insolubility in water and in most common solvents and its low resistance against microbial attacks . FurtherIn the current review, we explore the (1) fundamental structural characteristics and properties of cellulose from various sources; (2) sustainable extraction processes; (3) chemical modifications used in the preparation of cellulose derivatives; and 4) various applications for cellulose derivatives. Special attention is given to recent sustainable strategies engaging extraction, dissolution, and modification of cellulose, with a particular focus on the utilization of deep eutectic solvents. In the literature, it is possible to find different reviews dealing with cellulose derivatives and their applications. However, most of them are focused on specific applications, such as biomedical applications  various , or wastCellulose is generated at the plasma membrane in the form of paracrystalline microfibrils . The hieCellulose can be obtained from various biomass sources, such as hardwoods , softwoods , forestry residues, agricultural wastes, or grasses. Most properties of the obtained cellulose are strongly dependent on the source of biomass; one of these properties is the molecular weight, which has deep effects on cellulose application and processability. For example, hardwood raw materials typically present degrees of polymerization (DPs) ranging from ca. 1400–1790 , but it The extraction process used to obtain cellulose also has an impact on the DP of the recovered cellulose. For instance, the sulfite process leads to less depolymerization than the kraft process ,16. AnotIn addition to cellulose, lignocellulosic biomass is composed of two other structural polymers (hemicellulose and lignin), along with other minor compounds such as proteins and fatty acids ,21. CellConsidering what is referred to above, the choice of the cellulose source will depend on the desired properties and application, its availability, and economic purposes. Nowadays, most of the cellulose fibers used worldwide are extracted from wood. Nonetheless, wood is not widely available in some regions, and there is also a competing interest among several industries related to construction, furniture, pulp and paper, and the burning of wood for energy harvesting. Thus, it can be challenging to supply the required quantities of wood at reasonable prices to all sectors . This enThere are various lignocellulosic biomass fractionation processes that allow the separation and isolation of the components; the choice of the most efficient method depends on the target polymer, source, and desired properties of the final product. Usually, cellulose is obtained by dissolving lignin and hemicellulose, along with low-molecular-weight compounds.Conventional methods for biomass fractionation, such as those used in the pulp and paper industry , are very efficient for the extraction of cellulose, but the nature of the solvents used and the harsh treatment conditions employed have led the scientific community to search for new environmentally friendly alternatives. The use of green solvent systems, such as ionic liquids (ILs) and deep eutectic solvents (DES), has been reported for biomass fractionation and demonstrated to be very promising systems , not onlILs, first reported by Paul Walden in 1914, are known as “molten salts” because they present a low melting point, usually below 100 °C , and arew/w) of the total lignin present in different sources, such as corn straw [In this context, DES have emerged as promising solvent systems due to their greener profile and high efficiency for biomass fractionation ,61. The rn straw . Systemsrn straw , ChCl anrn straw , and ChCrn straw  are partrn straw . Despitern straw .Cellulose is a high-molecular-weight linear homopolymer composed of D-anhydroglucopyranose units (AGU) connected by β(1–4)-glycosidic bonds . Each AGAs shown in The reactivity of the hydroxyl groups combined with their tendency to establish hydrogen bonds is responsible for some of the characteristics of cellulose, such as its highly cohesive nature and remarkable mechanical features . Throughw/w) of the total cellulose fiber, and it is very dependent on the cellulose source and extraction conditions [The crystalline fraction typically ranges between 40% and 70%  their inherent chemical reactivity; (2) steric effects that may arise from the reacting agent; and (3) steric effects that are driven by the supramolecular structure of cellulose . In mostOne important class of reaction in cellulose is esterification. In this respect, it has been found that the OH at the C6 position is more prone to react than the OHs at the other positions. Moreover, the OH at the C2 position reacts twice as fast as the OH at the C3 position in esterification reactions . In compDespite the favorable presence of reactive OH groups, reactions involving cellulose are typically not easy, mainly because cellulose is highly heterogeneous in nature. As discussed above, different parts of its constituent fibrils display very different accessibilities to the same reagent  . The accThe efficiency of the activation process (swelling/dissolution) deeply influences the capacity to facilitate and control reactions with the three hydroxyl groups in each AGU . It is iCellulose is a fascinating polymeric material and possesses several favorable features, but it also presents some drawbacks, such as its poor solubility in common solvents and its lack of thermoplasticity and antimicrobial properties. To overcome such limitations, controlled chemical modification of the cellulose structure is often a suitable strategy ,85.Dimensionally speaking, cellulose derivatives fall into two main categories: macromolecular cellulose derivatives and nanoscale particles . EtherifTo improve cellulose reactivity and allow further modifications, pretreatments are often performed to introduce more reactive groups into the cellulose structure. One example is the oxidation of cellulose to convert the hydroxyl groups into more reactive aldehyde groups that can then undergo other derivatizations. Regarding the oxidizing reagents used in cellulose chemistry, many can be enumerated, such as nitrogen oxides, alkali metal nitrites and nitrates, ozone, permanganates, and peroxides. These agents usually lead to reactions with low selectivity. However, cellulose oxidation with periodates presents a very high selectivity , while mSeveral reaction parameters may influence the properties of the obtained DAC, such as the concentration of periodate , temperature, and reaction time. The pH effect is also an important parameter to control during the oxidation of cellulose. It was reported that, in acidic conditions (pH < 3), the hydrolysis of cellulose is enhanced, resulting in superior degradation of the fibers . UsuallyAlthough periodate oxidants are toxic, environmentally harmful, and relatively expensive, their recycling and reuse may make the process more sustainable and feasible, both from environmental and economic perspectives . MoreoveCellulose, usually obtained as cellulose fibers from wood sources, is typically negatively charged due to the ionization of the hydroxyl groups. The functionalization of cellulosic materials with cationic moieties has been a chosen strategy to confer affinity toward other negatively charged molecules/particles and expand the applicability of cellulose derivatives. Cationic celluloses have been applied as bio-based flocculant and/or adsorbent alternatives for water treatments ,95. AddiTwo main strategies are described in the literature for the cationization of cellulose. The first one involves the physical adsorption of cationic polymers into the cellulose surface , and theAlthough cations from various atomic elements can be used for cationization , most of the literature focuses on the use of nitrogen-derived compounds. Depending on the derivative, the charge can be pH-dependent, with the cationic group being formed due to the protonation of amines  or heterocyclic compounds (pyridine and imidazole) under acidic conditions. On the other hand, quaternary ammonium derivates present a permanent pH-independent positive charge ,103.One common method for cellulose cationization is based on direct modification by dissolution of short-chain cellulose molecules in aqueous solutions , which are pre-cooled to sub-zero temperatures, followed by cationization in a homogeneous medium with N-(3-chloro-2-hydroxypropyl)trimethylammonium chloride (CHPTAC). In this system, the reactive epoxy reagent is prepared in situ by reacting CHPTAC with alkali A. The epAn alternative approach considers the cationization of pre-modified cellulose by using, for example, DAC , CA, or w/w)). The solubilization of the fibrils was not detected.The direct cationization of wood cellulose fibers with CHPTAC and the indirect method with GT were both tested by Pedrosa et al.  as a preSirviö et al.  reportedEmam et al.  reportedAlthough cellulose anionization is not as well explored as cationization, there are some procedures described in the literature. For example, Rajalaxmi et al.  and GrenIn Grenda et al. , after tw/w) water was found to be the most promising mixture. The use of ball milling in the process reduces the cellulose particle size, increases the surface area of cellulose, promotes the interaction between DES and the cellulose molecules, and disrupts the crystalline structure, thus increasing the carboxylic content in the modified cellulose.Cao et al.  have synCellulose molecules possess a great number of hydroxyl groups, leading to fibers with a strong polarity and high water sorption capacity. However, most of the synthetic polymeric matrices are nonpolar, such as plastics (polyethylene or polypropylene are among the most common) . Therefo31P NMR) can be achieved under mild conditions for acetylated and carbanilated wood, respectively [Homogenous acetylation and carbanilation reactions of wood-based lignocellulosic materials in ILs have also been investigated, resulting in highly substituted lignocellulosic esters . A high ectively . The optThe preparation of hydrophobically modified cellulose from renewable feedstocks (based on green chemistry principles) can be met using plant oils. Plant oils are triglycerides with hydrophobic long hydrocarbon chains, which have been exploited as sustainable alternatives to materials derived from non-renewable resources . Yoo et 4)2Ce(NO3)6) [Another widely used way to modify the surface of polysaccharides and make them more hydrophobic relies on the introduction of acrylates and methacrylates into the chain. Littunen et al. studied the filling of various acrylates and methacrylates as monomers through a free radical copolymerization initiated by ammonium cerium (IV) nitrate ((NHe(NO3)6) . InitiatAn important advantage of this method is that the entire synthesis can be performed in an aqueous medium. The macrostructures formed by the grafted polymers ranged from a thin coating to a continuous matrix completely enveloping the fibrils. This type of modification can offer a simple way of improving the compatibility between lignocellulosic materials and synthetic polymers.13C NMR spectrum in The introduction of siloxane groups into the cellulose structure is another suitable approach to enhancing the hydrophobicity of the molecule. Schuyten et al. introduced, almost 70 years ago, the first cellulose derivative, trimethylsilylcellulose (TMSC) ,122,123.Later, some improvements in the TMSC synthesis led to products soluble in organic solvents, such as chloroform, 1,1,1-trichloroethane, and o-xylene . The disFrom the examples discussed above, it is clear that lignocellulosic materials can be modified in many different ways. The choice of the most suitable method will depend on the desired properties of the cellulose derivatives and the application foreseen.Chemical modification of low-cost, naturally occurring raw materials, such as cellulose, is an important and promising route for the development of green value-added products. Cellulose derivatives are currently used in different areas, such as food formulations, coatings, or films with barrier properties ,126,127 An edible cellulose-based film for probiotic entrapment was prepared by Singh et al.  using soIn the biomedical area, the use of cellulose derivatives as controlled drug release systems is very appealing ,132. NanThere are numerous cellular species that can be cultured on nanocellulose biomaterials, such as hydrogels, electrospun nanofibers, sponges, composites, and membranes . Among tFuller et al.  studied Cellulose derivatives are also reported as efficient flocculants, namely for the flocculation of pigments  and calcIn the textile industry, cellulose modification can also be applied to enhance dye uptake into textile fibers. A potentially environmentally friendly dyeing method using a cationization method in combination with mercerization was proposed by Fu et al. . The catCellulose is the most abundant natural polymer on Earth. Due to its wide availability, it is a very promising raw material for the replacement of non-renewable feedstocks. To overcome some limitations of its application and expand its valorization and utilization, cellulose can be chemically modified to improve its chemical and/or physical properties. Numerous studies reporting the modification and application of cellulosic materials are available in the literature. In the present review, some of the most common chemical modifications of cellulose  are briefly described, and selected applications of these derivatives are presented. Cellulose and its derivatives can be obtained from different sources, including biomass such as agroforestry residues, and are suitable for a wide range of applications. A brief review of possible fractionation procedures is also presented, including greener alternatives. By understanding cellulose structure and reactivity, it is possible to tune the properties of the resultant material, such as by modulating the hydrophilic/lipophilic balance, charge, or degree of polymerization, to obtain materials with improved performance for the intended application. The overall range of material applications for cellulose derivatives is virtually limitless.In summary, cellulose appears to be a sustainable, environmentally friendly feedstock with valuable properties such as its biocompatibility, non-toxicity, and wide availability, and the study of new routes to improve its properties and applications is of great interest. The cellulose derivatives are suitable for the replacement of fossil-based products and are an important alternative to reduce the environmental problems derived from the use of petroleum-based materials and fuels. Indeed, cellulose and its derivatives can provide the biological, chemical, physical, and engineering communities with new opportunities for exciting advancements and discoveries.


Therefore, COF-PLA degradation does not cause pollution, making it a promising sand-control material.A new high-strength, thermally stable, and degradable covalent organic framework (COF) -modified polylactic acid fiber (PLA) material (COF-PLA) was constructed for reinforcing the PLA material, to be used to produce environmentally friendly sand barriers. The micrographs, structure, thermal stability, and photodegradation products of COF-PLA were investigated. The results indicated that the COF material was compatible with PLA, and that the COF-PLA material took on the merits of the COF, so that it had a more regular arrangement, smoother surface, and smaller size, and was more thermostable than PLA alone. The successful incorporation of the COF improved the thermal stability of PLA. The initial pyrolysis temperature of the COF-PLA material is 313.7 °C, higher than that of the PLA material at 297.5 °C. The photodegradation products of COF-PLA and PLA indicated that the COF and PLA materials were mixed in a complex manner. After photodegradation, the COF-PLA material can produce melamine molecules that can neutralize the lactic acid and CO Land desertification is an environmental and ecological issue, and one of the greatest threats to humanity in the 21st century . Most laVarious plant, mechanical, and chemical measures have been used to combat desertification. Mechanical sand-control measures, such as sand barriers, are usually used in harsh deserts where plants struggle to survive. These methods can stop the forward movement of sand dunes, stabilize the shifting sands, and create stable terrain for plants to grow . Mechani2 and H2O, and therefore does not cause secondary pollution to the environment [Many studies have been reported on mechanical sand barriers , includiironment ,10. Compironment .However, the development and application of PLA are limited due to its high price, unstable mechanical properties, and low thermal stability, which are in urgent need of improvement ,13. CompTherefore, the modification of PLA with plant fibers can not only improve the mechanical properties of PLA products, but also reduce their cost while maintaining their reported benefits. These composites can greatly increase the scope of PLA applications, and many studies have focused on preparing PLA-based composites using natural plant fibers as reinforcements. Ghazali et al.  preparedHowever, plant fiber, or cellulose, is usually produced by chemical extractions, such as the alkali cooking method with the chemical extraction process, which has many extraction steps and may cause chemical contamination during production ,23. CovaBhadra et al.  found thIn recent years, COFs have been widely used in storage adsorption ,28, hydrIn this study, chemically stable and cost-effective COF materials were prepared using a one-step method, and the micrographs, structure, thermal stability, and photodegradation of PLA modified by a highly structured COF material were studied.Lactic acid . Zinc oxide . Ethyl acetate . Stannous octoate . Trichloromethane . Methyl alcohol . Melamine/1,3,5-Triazine-2,4,6-triamine . 2,4,6-Triformylphloroglucinol aldehyde . Acetic acid . α-cellulose . Dimethylacetamide . Dimethylsulfoxide .Fourier transform infrared spectrometer . Thermal gravimetric analyzer . Circulating water multi-purpose vacuum pump . Ampere bottle . Vacuum drying oven . Thermo Exactive-GC mass spectrometer . Brunauer–Emmett–Teller automatic surface and porosity analyzer . X-Ray Diffraction, XRD .First, 200 mL of lactic acid was distilled to dehydration in a vacuum pump under reduced pressure at 100 °C. Zinc oxide was dried at 500 °C and then added to produce a 1% by volume solution in the lactic acid. The temperature was then adjusted to 150 °C and the mixture was distilled for 3 h to yield lactide. Next, 5 g lactide was dissolved in 10 mL ethyl acetate at 45 °C, then cooled at room temperature to obtain pure lactide with a yield of approximately 75%.Next, pure lactide was vacuumed and frozen in an amperometric flask. Stannous octanoate with a mass fraction of approximately 0.1% lactide was added. The mixture was thawed slowly and then heated for thorough mixing. The mixture was taken through three cycles of thawing, vacuum, and a high-purity nitrogen gas exchange operation before the amperometric flask was sealed under vacuum conditions and placed in an oven at 220 °C for 48 h to produce the PLA. The resulting PLA is shown in At 150 °C, 38 mg of melamine (Tt), 63 mg of 2,4,6-triformylphloroglucinol aldehyde (Tp), 2 mL DAMc, 1 mL DMSO, and 0.3 mg of Hac (acetic acid) catalyst were placed in a test tube to react for 48 h. During this period, the aldehyde groups in phloroglucinol and trimylamine reacted to form a structurally stable reticular COF structure with multiple aldehyde groups. A schematic representation of the COF synthesis is shown in One gram of PLA was dissolved in 50 mL of chloroform and refluxed to thoroughly dissolve the solid. Next, 2 mg of COF nanomaterial was added to the refluxing mixture. After the complete dissolution of the solid, the mixture was allowed to cool. The PLA-COF solution was added dropwise while stirring into 150 mL of methanol. After the separation of the solid product from the solution was observed, the flocculent product was washed with methanol and the resulting COF-PLA was obtained, as shown in According to the solubility parameter close principle, the COF can be dissolved in chloroform since both COF and chloroform are polar. Additionally, the dissolution did not change the COF structure. For example, the structure of a polymer dissolved in toluene remains unchanged. In addition, COF affords ultrahigh chemostability in strong acid, alkali, and boiling water, as well as γ radiation . TherefoHowever, as COFs have a stable structure and large molecular weight, their solubility in chloroform is poor. Therefore, we prepared different COF-PLA materials with weight ratios (COF/PLA) of 1:300, 1:500, and 1:1000.Micrographs of the samples were obtained using scanning electron microscopy. The samples were sprayed with gold before imaging, and an acceleration voltage of 10 kV was applied.Brunauer–Emmett–Teller (BET) analysis was used to determine the surface area (SBET) of the COF.The crystalline structures of the synthesized nanomaterials were identified using powder X-ray diffraction (PXRD).−1.Fourier-transform infrared spectroscopy (FT-IR) was used to study the molecular structure and chemical composition of the samples in the range of 500–4500 cmThe thermal decomposition process, thermal stability, and compositional changes in the samples were analyzed by TGA using a thermal analyzer. The temperature ranged from room temperature to 500 °C with a heating rate of 10 °C/min, a nitrogen flow rate of 30 mL/min, and a sample volume of approximately 5 mg.First, 50 g of sand was washed, dried, and placed in a flat quartz boat. Second, 0.1 g PLA or 0.1 g COF-PLA composite material was dissolved in chloroform and slowly dripped onto the sand in the quartz boat. Subsequently, a stable layer of the PLA or COF-PLA was formed on the sand surface after the solvent evaporated. The PLA membrane was colorless and the COF-PLA membrane was light yellow. Next, the PLA and PLA-COF quartz boats were doused with a small amount of water and placed under a wired light source with a current of 10 A. As irradiation proceeded, the color of the PLA quartz boat became more yellow, and the COF-PLA quartz boat became lighter, indicating that both PLA and COF-PLA were degraded. Finally, the degradation products of the PLA and COF-PLA materials were analyzed using liquid mass spectrometry.Micrographs of the synthesized materials are shown in 2/g. The surface area (SBET) of the COF was determined by the Brunauer–Emmett–Teller automatic surface and porosity analyzer. The Brunauer–Emmett–Teller (BET) analysis of the COF revealed that it had a surface area (SBET) of 169.20 m−1, which correspond to -OH stretching and bending vibration peaks, respectively. The troughs at 2947 and 2998 cm−1 correspond to the -CH symmetric and asymmetric stretching vibration peaks, respectively. The peak at 1213 cm−1 was caused by the C-C stretching vibration. A C-O stretching vibration peak was observed at 1127 cm−1. The characteristic peak of the amorphous phase for crystalline is shown at 871.2 cm−1, and the peak at 756 cm−1 is caused by the crystalline phase. This spectrum is in agreement with the spectroscopic results of a previous study [us study , confirm−1. The peak at 3210 cm−1 is characteristic of the hydroxyl group on the benzene ring. The peaks at 1615 and 1651 cm−1 were attributed to the C=O double bonds in the COF material. The vibration peak of the trimylamine ring group was observed at 832 cm−1, and the vibration peak at 808 cm−1 was attributed to the benzene ring. These results confirmed the successful synthesis of new COF materials containing both melamine and benzene ring structures.−1, amorphous phase correlation peak at 871 cm−1, and crystalline phase correlation peak at 756 cm−1, but also the vibration peaks of the new COF material, including the C=O double bond vibration peak at 1619 cm−1 and the benzene ring vibration peak at 810 cm−1. Hence, As shown in 3-CH-C=O group from the PLA structural units and belongs to a metastable structure. The fragment with a mass of 182 was formed by removing a hydrogen proton and a sodium ion from the metastable structure mentioned above. The fragment with a mass of 455 was formed by removing a hydrogen proton from six PLA structural units and one sodium ion. A fragment with a mass of 504 was formed from seven PLA structural units. The fragment with a mass of 527 was composed of seven PLA monomers and one sodium ion, which belongs to a metastable structure. A fragment with a mass of 670 was formed from nine PLA structural units and one sodium ion, with a hydrogen proton removed. A fragment with a mass of 631 was formed by removing one oxygen atom from the nine PLA structural units belonging to the steady-state structure.As shown in As shown in 2. The remaining PLA can be biodegraded and the remaining unstable CO2 can be absorbed by the atmosphere or plants. This process allows the acid–base balance of sandy soils to be maintained even as the material degrades, thus supporting plant growth. The photodegradation products of COF-PLA and PLA in the spectra confirmed that the COF and PLA materials were mixed in a complex manner. The degradation of COF-PLA resulted in the formation of melamine monomers that neutralized the lactic acid and carbon dioxide degraded from PLA. This is a useful balancing process because all stable melamines can be neutralized with PLA and COAs can be seen from In addition, due to the low solubility of COF in chloroform, lower weight ratios between COF and PLA result in a better doping effect and, therefore, better thermal stability of COF-PLA. Furthermore, the presence of water vapor may lead to the production of nitrogen in the COF pyrolysis process. Nitrogen is an essential nutrient for plant growth, and this process may allow the COF-PLA to act as a fertilizer for sand-fixing plants while also contributing to sand fixation.In this study, we prepared a highly chemically stable and cost-effective COF material through a one-step method, and modified PLA with this COF to prepare a new degradable COF-PLA material with good thermal stability for use in high-strength sand barriers. Compared to other materials used as sand barriers, COF-PLA materials are simple to prepare, pollution-free, and economical. Furthermore, the experimental results illustrated that the new COF-PLA material had a stable structure, regular arrangement, smooth surface, and strong heat resistance. During the degradation process, the COF-PLA produces a melamine monomer which can neutralize the lactic acid and carbon dioxide produced during the degradation of PLA. This may help maintain the acid–base balance between sandy soil and plant growth. This new COF-PLA material has great potential applications for sand fixation in desert regions.


Polylactic acid (PLA) is a biodegradable polyester polymer that is produced from renewable resources, such as corn or other carbohydrate sources. However, its poor toughness limits its commercialization. PLA composites can meet the growing performance needs of various fields, but limited research has focused on their sustainable applications in sports. This paper reviews the latest research on PLA and its composites by describing the characteristics, production, degradation process, and the latest modification methods of PLA. Then, it discusses the inherent advantages of PLA composites and expounds on different biodegradable materials and their relationship with the properties of PLA composites. Finally, the importance and application prospects of PLA composites in the field of sports are emphasized. Although PLA composites mixed with natural biomass materials have not been mass produced, they are expected to be sustainable materials used in various industries because of their simple process, nontoxicity, biodegradability, and low cost. The continuous advancement of science and technology has increased the global demand for natural resources, leading to frequent problems, such as material shortages and environmental pollution. Rapidly depleting oil reserves, greenhouse gas emissions, and the large-scale use of oil-based products have resulted in a lack of biodegradable products, prompting researchers to explore biodegradable, renewable, and recyclable materials. Polylactic acid (PLA) is a biodegradable bio-based aliphatic polyester that can be extracted from 100% renewable resources, such as corn, potatoes, and sugarcane ,3,4,5.2/kg PLA) of the released CO2 in the PLA life cycle is released during its conversion. By optimizing the conversion process of PLA, there is tremendous potential for PLA to become a low-carbon material [PLA is an extracted thermoplastic that is suitable for manufacturing composite materials using various methods, such as injection molding, extrusion molding, and compression molding . Increasmaterial .This report discusses the latest developments in the research and development of PLA and its composites. It first outlines the basic structure, characteristics, production, degradation process, and latest modification methods of PLA, and it discusses the inherent advantages of selecting PLA composite materials and focuses on the relationship between different biodegradable materials and their performance in the final PLA composite materials. Then, it introduces the application prospects of PLA composite materials in the field of sports. Finally, it discusses the challenges faced by PLA composite materials and competing materials.2O and CO2. After photosynthesis, CO2 and water are converted back into substances such as starch, which can be used as raw materials to resynthesize PLA, thereby realizing a carbon cycle process [PLA is an entirely biodegradable polymer hailed as one of the most promising bio-based polymers because of its biocompatibility, biodegradability, high mechanical strength, nontoxicity, nonirritation, and processability. PLA can be synthesized by low-energy processes, and it is independent of petroleum resources. Microorganisms can decompose waste PLA into H process  that doeLactic acid molecules contain a chiral asymmetric α-carbon atom and exhibit optical activity that can be divided into two configurations: left-handed (L) and right-handed (D). The dehydration of two lactic acid molecules forms three optical isomers of lactide: L-lactide, D-lactide, and meso-lactide. L-lactide is cheaper because it is naturally occurring. The content of D-lactic acid changes the crystallization behavior of PLA, including different crystallization rates, multiple crystal types, different scales, and layer thicknesses. The crystal morphology is closely related to the mechanical properties of the polymer: the larger the PLA crystal, the more defects in the interior and on the surface of the crystal, and the poorer the mechanical properties of the resulting material . Like L-Mw). When the molecular weight doubles from 50 kDa to 100 kDa, the PLA’s tensile strength and elastic modulus also double [PLA is a member of the family of aliphatic polyesters and has the essential characteristics of universal polymer materials. PLA has a tensile strength similar to that of polyethylene terephthalate (PET), approximately 54 MPa, while its tensile modulus is 3.4 GPa, which is slightly higher than that of PET ,15. The o double . The meco double ,18.2O and CO2.The environmental degradation process of PLA occurs in two steps: hydrolysis and microbial degradation. PLA first undergoes the hydrolytic cleavage of ester bonds, degrading into PLA oligomers (OLAs) . The hydIn the late 1980s, the advancement of direct condensation technology significantly increased the global production of PLA and greatly reduced its costs. Direct condensation involves preparing PLA by dehydrating and condensing lactic acid molecules. The disadvantage of this method is that the reaction system is in a dynamic equilibrium between condensation and depolymerization, and the high viscosity of the system makes it difficult to remove the water by-product. The unremoved water causes the depolymerization reaction to proceed, even under vacuum conditions, making it difficult to extract water and increasing the molecular weight of the PLA. Under a high temperature (>200 °C), the PLA will undergo depolymerization, discoloration, and racemization accompanied by a series of side reactions, such as ester exchange, which may form differently sized cyclic products. This results in reduced product properties and poor mechanical properties, which limit their industrial applications. However, the use of direct condensation to produce PLA is a short and inexpensive method. Chen et al. used a combination of direct condensation and melt polymerization using tetra butyl titanate as a catalyst. They used different vacuum periods, esterification, and condensation reactions. The results showed that this method reduced the system’s viscosity, thus helping to remove water and increase the molecular weight .In the early 1990s, Cargill Inc. applied for a patent for a solvent-free process and new distillation technology based on ROP to convert lactic acid into high-molecular-weight polymers. This made PLA the second-highest volume bioplastic after starch-based materials. By utilizing specific microbial strains, natural agricultural materials can undergo fermentation to produce lactic acid (LA), which is a precursor for PLA ,35. The According to Refs. ,38,39, tPLA is a thermoplastic polymer whose processing temperature is generally between 170 and 230 °C. In recent years, researchers have produced self-reinforcing PLA through techniques such as melt extrusion, stretching, and injection molding without the need for additives, which retain the biocompatibility and biodegradability of PLA. This method can also solve the trade-off between the toughness and strength and compatibility of blends. In addition, Cao et al.  designedChrissafis et al.  added 2.Researchers can improve the mechanical properties of polymers by changing the structure and composition of copolymers. Adjusting the ratio of lactic acid and other monomers in the copolymer system can produce copolymers with the desired mechanical strength to improve the mechanical properties of PLA. By utilizing the hydroxyl and carboxyl groups on the lactic acid segment, different monomers, such as caprolactone (CL), ethylene oxide (EO), ethylene glycol (EG), and trimethylene carbonate (TMC), can be used to synthesize PLA copolymers with improved mechanical properties, especially toughness. Li et al.  prepared2 and H2O, requiring temperatures near the Tg (60 °C) of the polymer and a high relative humidity [2 emissions are offset by the initial absorption during PLA production. Under such conditions, the degradation time can be as short as 30 days.PLA is a biopolymer that can also undergo biodegradation under certain conditions without producing environmental pollution ,46. Polyhumidity . The CO2Ea = 53.2 kJ mol−1), and the second mechanism was associated with a self-catalytic effect of increasing carboxylic acid groups during the depolymerization process (Ea = 36.9 kJ mol−1). This effect was previously noted in PLA hydrolysis and lowered the solution pH. The group’s further work modeled the hydrolysis of PLA at higher temperatures (170–200 °C). The kinetic model described the batch erosion of PLA and subsequent hydrolysis of oligomers, and the model accurately predicted the conversion and concentration of oligomers. Under these conditions, PLA could be completely transformed within 90 min.Piedmont and Gironi  studied Although PLA has excellent mechanical properties, renewability, biodegradability, and low costs , Figure Natural fibers can be divided into plant and animal fibers according to their sources . GeneralCellulose nanocrystals (CNCs) are rod-shaped nanoparticles extracted from cellulose through acid hydrolysis. A wide range of sources, including bleached wood pulp, cotton, and hemp fibers, can be used to produce CNCs ,62. BecaSince Favier et al.  first atLignin is the most abundant aromatic biomass in nature, accounting for 20–30% of the weight of wood ,68. MostSpiridon et al.  obtainedSilk fiber is a natural animal protein fiber with a higher crystallinity, toughness, and tensile strength than plant fibers . In addiZhao et al.  prepared2 and H2O and are nontoxic to the soil and air [As a new bio-based polymer material, PHA has diverse structures, various sources, and biodegradability, biocompatibility, optical activity, piezoelectricity, and gas barrier properties. They can be naturally biodegraded into CO and air ,78. Curr and air ,80.Zembouai et al.  studied gT), indicating the poor compatibility of unmodified PBAT/PLA blends. In experimental studies, the preparation of PBAT/PLA blends usually involves melt blending. At high temperatures and sufficient time, ester exchange reactions occur between the two polyesters, thereby improving their compatibility [PBAT is a biodegradable material produced on large scales and widely used in packaging materials and biomedical fields. PBAT has good processability and can toughen and modify other polyesters , but comtibility . By incrtibility .Arruda et al.  preparedMicrocellular injection molding was first proposed in the 1980s by Nam et al. . The forExtrusion molding can be divided into continuous and intermittent types based on the different pressures used during extrusion. Continuous extrusion applies pressure with the rotation of a screw to uniformly plasticize the material inside the barrel. The material undergoes mixing and heating through the action of the screw during the extrusion process, resulting in good material uniformity . IntermiCompression molding is a standard processing method for PLA. During compression molding, PLA particles are placed in a heated mold, and pressure is applied to liquefy and flow the material at high temperatures . As the The global production capacity of all biodegradable plastics, including PLA, is expected to increase rapidly to approximately 1.33 million in 2024 , with prPLA fiber is a biodegradable synthetic fiber that is refined and fermented from starch sugar in corn, beets, or wheat. It is a new type of polyester fiber in the textile industry. PLA fiber is 100% compostable and reduces the Earth’s carbon dioxide levels throughout its entire life cycle. The cross-section of PLA fiber is generally circular with a smooth surface. Its load–elongation curve is similar to that of wool, while its toughness is lower than that of cotton. PLA fiber has good core absorbency and fast moisture management. Therefore, by blending PLA fiber with cotton, the moisture transmission properties of cotton fabrics can be improved. Guruprasad et al.  developeRaykar et al.  used PLATraditional protective sports gear has a structure consisting of a hard outer shell made of a thermoplastic material and an inner soft foam padding. Currently, there are new “soft shell” technologies for sports protectors based on the use of soft polymer foams typically made of polyurethane or polyacrylate with good cushioning properties. During the manufacturing process of sports protectors, soft polymer foams can be combined with PLA. Soft polymer foams are used as the internal cushioning material. In contrast, PLA can be used as the outer shell material to improve sports knee protectors’ lightweight, breathability, and comfort properties, thus achieving better protection results. Yang et al.  used tenThe source of power for a surfboard comes from the movement of waves, and the significant impact force generated by an impact wave can often break a surfboard, mainly when materials such as fiberglass are used in its production. In recent years, researchers have turned their attention to biodegradable materials. Soltani et al.  used theBecause of the biocompatibility and biodegradability of PLA when in contact with mammalian bodies, it has been widely used in the biomedical and pharmaceutical fields  to manufCompared with traditional printing materials, PLA produces almost no harmful gases and has a lower shrinkage rate, making it ideal for 3D printing sports equipment. Protective gear, such as mouthguards, helmets, and shin guards , can be Compared with traditional petroleum-based plastic sports equipment, the green disposal of idle sports equipment meets the requirements of sustainable development. Sports equipment made of PLA composites can be used safely and decomposes after being discarded, which can prevent environmental pollution. In addition, PLA has a lower density, allowing for the production of relatively lightweight sports equipment. Through 3D printing, PLA enables personalized customization, offering more possibilities for the innovative design of sports equipment. However, as a linear thermoplastic polyester, PLA’s strength may not meet the requirements of certain sporting equipment in specific environments. For example, because of PLA’s high brittleness and low elongation at break , sports PLA is a natural, renewable, and low-cost biodegradable material, but its inherently poor toughness limits its broader applications. By adding reinforcement materials to develop PLA composites, it can adapt to the increasing performance requirements of various fields. Compared with most inorganic and synthetic fibers, natural fibers have abundant sources, low prices, complete degradability, low energy consumption, and environmental friendliness. In the future, appropriate additives, modifications to polymerization conditions, and reinforcement techniques will be employed to enhance the strength of PLA and meet specific needs. At the same time, by developing low-cost reinforcement materials and optimizing formulations and processing methods, the manufacturing costs of PLA composites can be reduced. Their performance can be improved to meet various environmentally friendly applications, including sports equipment manufacturing. Currently, the application of PLA composites in the sports field is expanding. Compared with petroleum-based materials, the mechanical properties of PLA composites still need to be improved. However, as biodegradable alternatives to petroleum-based plastics, they still have tremendous potential.


In the history of cellulose chemistry, hydrogen bonding has been the predominant explanation when discussing intermolecular interactions between cellulose polymers. This is the general consensus in scholarly textbooks and in many research articles, and it applies to several other biomacromolecules’ interactions as well. This rather unbalanced description of cellulose has likely impacted the development of materials based on the processing of cellulose—for example, via dissolution in various solvent systems and regeneration into solid materials, such as films and fibers, and even traditional wood fiber handling and papermaking. In this review, we take as a starting point the questioning of the general description of the nature of cellulose and cellulose interactions initiated by Professor Björn Lindman, based on generic physicochemical reasoning about surfactants and polymers. This dispute, which became known as “the Lindman hypothesis”, highlights the importance of hydrophobic interactions in cellulose systems and that cellulose is an amphiphilic polymer. This paper elaborates on Björn Lindman’s contribution to the subject, which has caused the scientific community to revisit cellulose and reconsider certain phenomena from other perspectives. In 2010, a paper by Lindman, Karlström and Stigsson discussed the mechanisms of cellulose dissolution, pointing out some discrepancies in the common literature, where hydrogen bonding was argued as the most crucial interaction to overcome. The paper (re)introduced hydrophobic interactions and cellulose amphiphilicity as essential to consider for the successful development of future cellulose solvents . Since tOocystis, and, due to this, the synthesis machinery was designated as the terminal complex (TC) . Th. Th+) orThe use of amphiphilic cations or species of intermediate polarity, such as urea or thiourea, typically enhances the stability of the cellulose dopes (delay of gelation), which is very important for many applications, such as fiber spinning ,79. ThisApart from the enhanced stability of cellulose solutions, the use of amphiphilic-like cations has been observed to improve dissolution and allows reaching a molecularly dissolved state of cellulose b. On the+, it was anticipated that if their beneficial effect in cellulose dissolution is related to weakening hydrophobic interactions, then once the cations are hindered or removed from the solution, cellulose’s solubility should be compromised. This hypothesis was successfully tested using different cyclodextrins (CDs) as host agents to form complexes with TBA+ cations [+ complexes was proven by NMR and the worsening of the solvent quality with CD addition was clearly observed from the polarized light microscopy and turbidimetry measurements. Overall, data support the hypothesis that the amphiphilic properties of TBA+ are determinant for the efficient dissolution of cellulose.Returning to the alkaline-based systems containing inorganic or amphiphilic-like cations, PTssNMR confirmed the higher degree of dissolution in the latter case; an intense “insensitive nuclei enhancement by polarization transfer” (INEPT) signal coming from dissolved cellulose . This is clearly seen in The driving forces responsible for cellulose regeneration and the formation of crystalline domains have been evaluated by different authors ; for insAt this stage, it is clear that in order to develop novel solvents for cellulose or improve existing ones, different aspects need to be considered. One of these important, but often neglected, effects that has been already mentioned is related to the ionization of cellulose. Note that, since hydroxyls were thought to be solely engaged in the H-bonds, it was disregarded that they could also be involved in other phenomena, such as ionization. The role of the cellulose charge and the concomitant ion entropy effects should not be underestimated . Contrar+ cations bind to cellulose with ca. 1.2 TBA+ ions/AGU [+ ions solvating the cellulose molecules [+ cations are suggested to be the main driving forces [+, it is reasonable to also anticipate a significant contribution from the hydrophobic effect regarding the favorable TBA+–cellulose interactions. These works strongly suggest that cellulose is, to a large extent, charged in a concentrated alkaline medium, an overlooked but relevant factor to rationalize its solubilization behavior.Further NMR studies have shown that TBAions/AGU . This waolecules ,96. Fromg forces . NeverthOrganic co-solvents, such as dimethyl sulfoxide (DMSO), have been observed to enhance cellulose’s dissolution, allowing the use of much less alkaline media ,97,98,99+, which demonstrates the preferential interaction of TBA+ with cellulose [+ suggests the weaker adsorption of the former. As mentioned, DMSO facilitates cellulose dissolution, not only by tuning the solvent viscosity (enhancing mass transport) but also by solvating cellulose , which facilitates further interaction between the TBA+ ions and cellulose. The highly polar character of the S-O bond in DMSO drives the overall negative charge density in the oxygen atom. On the other hand, the sulfur atom, despite displaying a positive charge density, carries a pair of non-bonding electrons [+, which further substantiates the preferred interaction of cellulose for the latter.The work of Idström et al. is particularly interesting since cellulose–DMSO contacts were found to be three times longer than the DMSO–DMSO interactions . Neverthellulose . The faclectrons . Thus, bAs an emerging class of biomass solvents, deep eutectic solvents (DES) are interesting. Mixtures of natural bio-sourced cations and anions , such as those obtained from natural organic acids, amino acids, non-nutritive sweeteners or natural compounds including choline or betaine, are particularly appealing due to their environmental benignity and relatively low cost when compared to, e.g., the synthetic ILs . However3PO4 (aq) [Cellulose is a versatile source of natural emulsifiers and can be utilized as such over the whole hierarchical size range, from cellulose particles and gels to macromolecules; see PO4 (aq) ,121,122.PO4 (aq) ,124,125.PO4 (aq) .One means of producing emulsions using dissolved cellulose is by following a dissolution–emulsification “in situ” regeneration approach, where the oil is directly dispersed in the cellulose solution and regeneration takes place at the oil–water interface (in situ). A continuous-like coating is formed around the oil droplet, giving it a smooth appearance ,121,124.Several researchers have also demonstrated the ability of cellulose particles to self-assemble at oil–water interfaces and to stabilize w/o emulsions without the aid of classical surfactants ,127,128.Cellulose dissolved in a good solvent is solidified when its solvency is decreased by any means, and this can be attained in several ways. Most commonly, different non-solvents (antisolvents) are being used to obtain this efficiently. Regeneration can also be imposed by, e.g., the addition of different salts or a combination of an antisolvent and salt. Remarkably, regeneration can also be triggered by temperature changes, without the addition of any other substances. In an aqueous solvent system comprising alkali and urea, gelation occurs via a sol–gel transformation when increasing the temperature of the cellulose solution , similarThe above-mentioned methodologies can be utilized when dissolved cellulose undergoes regeneration into the solid state to control the degree of crystallinity. Since crystallinity affects many different material properties of the solidified cellulose, such as the surface morphology, transparency and haze, mechanical strength, density, water contact angle, moisture uptake and gas permeability ,132, thiGlobal warming and the accumulation of microplastics in the oceans have driven research efforts toward developing bio-based and biodegradable materials to replace petroleum-based products. At the beginning of 2023, the European Polysaccharide Network Of Excellence (EPNOE) released the Research Roadmap 2040, a strategic document that summarizes the most relevant scientific questions to be answered for biomass and polysaccharides during the coming decades . CelluloRecently, a promising breakthrough in IL development for the dissolution of cellulose was achieved by research groups in Finland, led by Profs. Herbert Sixta and Ilkka Kilpeläinen . The metThe first isolation of nanocellulose occurred in the mid-20th century , while tConsidering the advances over the past twenty years, several challenges have been identified that hinder the transition of nanocellulose production and utilization to a large industrial scale. To overcome the difficulties, improvements in the production efficiency with environmentally friendly approaches and less energy-consuming processes to lower the cost are strongly recommended ,156,157.N,N-dimethylacetamide [The term all-cellulose composite was first introduced by Nishino et al. . By distcetamide . Via thecetamide . Regenercetamide .2SO4 [®80. Thereafter, the sol–gel transition was triggered by increasing the temperature of the w/o emulsion and lowering the solubility of the biopolymer, to solidify the cellulose–chitosan droplets into micrometer-sized spherical nanocomposites. The two types of chemically or physically crosslinked microparticles obtained were thereafter washed, solvent-exchanged, freeze-dried from tert-butanol and thoroughly characterized.Yang et al. prepared transparent and flexible cellulose–montmorillonite nanocomposite films by dissolving cellulose in a montmorillonite-dispersed LiOH–urea aqueous solution, followed by regeneration in acetone . The hig2SO4 . Composi2SO4 ,164. Fro2SO4 . The out2SO4 . ParticlQi et al. reported on a sensor system prepared from cellulose dissolved in alkali–urea mixed with multi-walled carbon nanotubes (MWNT) and regenerated. MWNT–cellulose films displayed both flexible and conducting MWNT characteristics in an interval of 2–10 wt% MWNTs. Films with multifunctional sensing ability for the monitoring of stress–strain, temperature and humidity were obtained, with potential for electronic, magnetic, semiconducting and biotechnological applications and as water sensors ,168.Cellulose-based fibers from a combination of hydrophilic cellulose and hydrophobic polyaniline (PANI) were prepared to yield antistatic fibers ,170. PAN−3 was reached in anisotropic nanofiber-structured cellulose films (ACFs). The well-aligned and densely packed cellulose nanofibers significantly decreased the interstitial spaces and minimized light scattering, giving ACFs with high optical clarity (91%), low haze (<3%) and birefringence behaviors. The simple methodology was argued to be scalable in fabricating high-strength, super tough and transparent cellulose films for emerging biodegradable next-generation packaging, flexible electronics and optoelectronic applications.Ye et al. recently presented a green route to the fabrication of strong and tough regenerated cellulose films . The fil2+ ions in a dispersion of alkali–urea-dissolved cellulose. The nucleation of the NPs was suggested to be initiated in the vicinity of the deprotonated hydroxyl groups in cellulose under highly alkaline conditions. Well-dispersed and spherical Cu/Cu2O NPs of a narrow size distribution decorating the cellulose were obtained. The hybrid material showed efficient antibacterial properties and its potential for catalytic and electronic applications was highlighted.An interesting approach to synthesize cellulose hybrid materials in situ has been described by Eivazihollagh et al. . A facil2 reduction, as with many other aspects of sustainability, are receiving increased attention scientifically and technically. Since the energy and climate crisis are two major challenges that we are facing, where the transition to green energy is urgently needed, this is an emerging field for cellulose-based materials. Cellulose can be utilized in many ways in energy storage and harvesting, and the whole value chain from the produced energy to the customer can thereby become more sustainable.An electrical energy supply and utilization are essential for the functioning of society. In May 2021, the International Energy Agency (IEA) released its roadmap to global net-zero emissions, analyzing the implications of existing net zero pledges and showing a pathway to net zero emissions in electric energy production globally by 2050 . In connCellulose in different forms has been widely used as a separator, electrolyte, binder and dispersion agent in material for energy storage devices . NanocelSupercapacitors are considered one of the potential candidates in the domain of energy storage devices for future generations. There is a wide variety of applications, such as storing waste energy to power electric vehicles and other electronic systems and balancing the electric grid from fluctuations that arise from renewable energy sources such as solar and wind power. Supercapacitors have generated great interest due to their high power density, long cycle lifetime and fast charge–discharge ,178. A sHajian et al. suggested that there is an association between nanocellulose and carbon nanomaterial, and the attraction increases with the surface charge of the cellulose . CNC wasBatteries are power sources with high energy density, consisting of one or more electrochemical cells, with external connections that can be used to power electrical devices, such as electric cars and mobile phones. A battery consists of a negative electrode (anode), a positive electrode (cathode) and an electrolyte, and a separator is sometimes used to prevent short-circuits. In batteries, a binder is used to prevent electrode swelling and mechanical degradation and to protect the active material against the electrolyte, with maintained ion transport throughout the binder . One of Historically, due to its excellent dielectric properties, cellulose (paper) has been and still is widely used as an insulator material in high-power transformers ,200. Bes−2 could be reached. This is a striking result that shows that, once processed correctly, cellulose can fulfil the demands regarding the performance to replace fossil-based polymers in TENGs. Nevertheless, there is still a limited fundamental understanding of how the structural characteristics relate to the electric properties of cellulose and affect the output in triboelectric applications. However, in a newly published study, the dependence of cellulose’s physical structure on different length scales was elaborated more systematically with regard to the triboelectric performance [Cellulose was recently demonstrated as a very potent triboelectric material . In a TEformance . SpecifiBy utilizing triboelectric counter-layers with different mechanical softness, effects from both surface roughness and surface polarity could be followed in triboelectric power generation. The assigned peaks at 2θ 12.3°, 20.5° and 22° in the XRD diffractograms shown in Cellulose, growing on land and in the oceans, is the largest biomaterial resource on Earth and therefore an exceptionally important renewable raw material for humanity. With Prof. Lindman’s profound revisiting of the fundamentals of cellulose, scientific discussions of the interactions and mechanisms in cellulose systems have been facilitated. Cellulose’s amphiphilicity has been highlighted, and hydrogen bonding, which often has been used as the sole explanation for cellulose’s intramolecular interactions in aqueous systems, has been reconsidered theoretically as well as empirically in many papers. This has led to a deeper understanding of the hierarchical cellulose and its behavior, from molecules to macrofibers. This work paves the way to new thinking in all areas of cellulose technology, which is vital for the continuous and incremental optimization of different processes involving cellulose, as well as for the future development and design of novel cellulose materials to replace petroleum-based ones, with the aim of sustainable development.