bluuebunny/crossref_metadata_2025_split huggingface dataset:
A detailed anatomical approach to taxonomically problematic endemic Seseli L. (Apiaceae) taxa in Türkiye
Authors: Mavi İdman Dudu Özlem 
Published: December 2023

AbstractIn this study, the vegetative anatomical features of the taxa, which were previously named as Seseli gummiferum subsp. ilgazense A.Duran, Ö.Çetin & M.Öztürk and S. paphlagonicum Pimenov & Kljuykov, were compared with a closely related species, S. resinosum Freyn & Sint., which is also endemic in Türkiye. The root, the stem, the leaf segment, the petiole, and the rachis parts were examined anatomically and explained in detail for the first time to discuss the results of recent morphological and molecular studies with the anatomy of the taxa. The results show that S. gummiferum subsp. ilgazense and S. paphlagonicum have anatomically similar characters. However, in terms of the same characters, these taxa quite differ from a closely related species, S. resinosum. The most prominent different characters can be listed as the shape of stems, petioles and rachis, the presence of sclereids in the roots, the collenchyma arrangement of stems and petioles, the surface view of rachis and the sclerenchyma above floem in the stems and rachis. This revisional and detailed descriptive study highlights the importance of anatomy in the taxonomy of Apiaceae, and it is obvious that it will assist future taxonomic research in the genus.Research Highlights
Vegetative anatomical characters are also taxonomically important as well as the fruit anatomy in the family Apiaceae.
The vegetative anatomy supports the molecular data that, the taxa named as S. gummiferum in Türkiye seem to be S. paphlagonicum.
Process controlled microstructure of polyvinylidene fluoride/functionalized single walled carbon nanotube composites
Authors: Roy Rinu Elizabeth , Rajeev R. S. 
Published: December 2023

AbstractPolyvinylidene fluoride (PVDF)‐functionalized single walled carbon nanotube (FSWCNT) film composites were prepared by two different process conditions—air drying and vacuum drying. Though reports on –PVDF‐FSWCNT composites are available, we provide a new outlook here, which is based on optimized functionalization and novel processing conditions. The microstructural and phase changes occurring in PVDF having nanotubes functionalized for different extent of time were investigated and confirmed that those functionalized for 4 h (FSWCNAT‐4) create polar γ phase in PVDF with improved mechanical and electrical properties. X‐ray photoelectron spectroscopy studies showed that PVDF/FSWCNT‐4 composites have the maximum percentage of functional groups. It is also found that PVDF/FSWCNT‐4 composite films prepared through air drying were rough and had a cloudy appearance suitable for applications demanding open porous structures, whereas those prepared through vacuum drying process were smooth and homogeneous with high optical transparency, suitable for microelectronic applications. Thus, by suitably controlling the processing conditions and by using optimally functionalized nanotubes, PVDF films with multifunctional properties could be achieved. In order to extract the full capabilities of PVDF/SWCNT films, functionalization of the nanotube together with processing conditions plays a significant role.
Load bearing investigations on novel Acrylonitrile butadiene styrene‐carbon quantum dots 3D printed core/bamboo fiber polyester sandwich composite for structural applications
Authors: Alshahrani Hassan , Arun Prakash V. R. 
Published: December 2023

AbstractIn this research, a novel 3D printed core and natural fiber polyester composite skin based thick sandwich panel was developed as structural material for domestic and commercial infrastructure applications. The main objective of this research was to analyze how the carbon quantum dots (C‐dots) from agriculture waste strengthen the softer thermoplastic acrylonitrile butadiene styrene (ABS) core and overall sandwich panel's load bearing properties. The core of sandwich was prepared using additive manufacturing method whereas the skin was developed by hand layup method. According to the results the C‐dots of 20 phr into the ABS improved the compression properties of core in both flatwise and edgewise directions. A highest tensile and flexural strength of skin was observed to be 114 and 146 MPa respectively. The addition of C‐dots improved the load bearing effect and also restricts the deformation against load. This performance improved novel 3D printed core and bamboo fiber skin sandwich could be used as an alternative construction and building material where the commercial plywood and other forms of powder wood face damages via weather and termite issues.Highlights
Higher filler volume of up to 20 phr of carbon quantum dots in acrylonitrile butadiene styrene (ABS) were developed
Novel 3D printed thin walled core of 1 mm diameter was developed using carbon quantum dots and ABS.
Bamboo fiber‐polyester skin with highest tensile strength of 114 MPa was developed.
Improved flatwise compression and tensile strength were achieved for ABS core with 20 phr of Carbon quantum dots
Flexural strength and edgewise compression properties were improved with 20 phr of Carbon quantum dots in ABS
Effect of hygrothermal aging on novel hybrid composites: Transforming textile waste into a valuable product
Authors: Russel Eastus , Nagappan Beemkumar , Karsh Pradeepkumar , Madhu S. , Devarajan Yuvarajan , Suresh G. , Vezhavendhan R. 
Published: December 2023

AbstractThe textile industry now produces thousands of tons of waste worldwide, and the total amount of discarded material waste increases yearly. Hygrothermal aging of cotton/E‐glass (hybrid) fiber reinforced with various proportions of graphene oxide (0%, 1%, 3%, 5%, 7%, and 9%) was performed. Epoxy and vinyl ester (50:50) have been chosen because of the Interpenetrating Polymer Networks (IPNs) concept. Laminates were subjected to 50, 60, and 70°C temperatures for 180 days. Further,Tgand the degree of cross‐linking have been determined by using differential scanning calorimetry (DSC). DSC analysis proves that a hot water bath enhances the cross‐linking of the polymer. IPN laminates were also intermittently weighed for water uptake, and their consecutive mechanical properties like tensile, flexural, and impact strength were obtained. From this work, it was observed that the addition of 5 w.t% graphene oxide in cotton/E glass fiber vinyl ester/epoxy resin hybrid IPN composites showed a tensile strength of 375.61 MPa, flexural strength of 393.54 MPa, Interlaminar shear strength (ILSS) of 49 MPa and the impact strength of 22.54 MPa. Moreover, the lowest inclusion of particulate addition exhibits better mechanical properties than (up to 5% of GO) the highest particulate loading into the matrix. SEM study was conducted on the broken specimens to know the impact of diffusion characteristics on the physical properties of the IPN composites.HighlightsNatural and synthetic fibers are used as reinforcements.Waste cotton/E glass fiber vinyl epoxy composites are fabricated.Laminates were subjected to diverse temperatures for 180 days.The moisture diffusion coefficient is proportional to water temperature.Bathtub temperature affects the tensile strength of the laminate.
Mechanical, morphological, and numerical evaluation of biocompatible ultra‐high molecular weight polyethylene/nano‐zeolite nanocomposites
Authors: Soudmand B. H. , Mohsenzadeh R. 
Published: December 2023

AbstractThe incorporation of bio‐friendly nano‐zeolite (NZ) into ultra‐high molecular weight polyethylene (UHMWPE), renowned for its exceptional biocompatibility, presents an intriguing pathway for robust structural biomedical applications. This study aimed to investigate the influence of NZ integration on the tensile and impact properties of UHMWPE/NZ nanocomposites through experimental and morphological assessments. The morphology examinations primarily entailed particle distribution, clustering extent, and the primary toughening response induced by fillers under impact loading. Fourier transform infrared spectroscopy (FTIR) was utilized to investigate the bonding characteristics between NZ and UHMWPE within the nanocomposites. Moreover, differential scanning calorimetry (DSC) was employed to examine alterations in the crystalline structure of the nanocomposites, revealing an increase of up to 9% in crystallinity () following the incorporation of NZ. Tensile tests demonstrated significant improvements, with a 45% increase in tensile modulus and a 14% increment in strength upon the inclusion of NZ. Impact toughness consistently showed enhancements of up to 24%. The improved impact strength was attributed to the extensive partial particle‐induced debonding and subsequent release of plastic constraints within the matrix. The micro‐mechanisms responsible for nanoparticle‐triggered toughening were further investigated using super‐magnified images from impact‐fractured SEM micrographs, and various impact toughening mechanisms were observed, classified, and discussed in the UHMWPE/NZ nanocomposites. Various analytical solutions were employed to predict the elastic modulus and tensile strength of nanocomposites. Subsequently, the results were compared to experimental data, and any discrepancies were thoroughly justified.Highlights
The mechanical traits of UHMWPE/nano‐zeolite nanocomposites were explored.
Tensile and impact strength increased up to 14% and 24% with NZ addition.
Morphological inspections were conducted to assess filler‐induced debonding.
Toughening mechanisms were assessed through super‐magnified SEM micrographs.
Micromechanical models were used to predict the tensile modulus and strength.
Biodegradable polymers and composites: Recent development and challenges
Authors: Maurya Atul Kumar , de Souza Felipe Martins , Dawsey Tim , Gupta Ram K. 
Published: December 2023

AbstractBiodegradable polymers are highly sought after as they have the potential to reduce the issue of plastic waste and eventually lead to a circular economy. Yet, conciliating eco‐friendliness with competitive properties is often challenging. Polymerization and processing techniques have been developed and optimized to improve such factors. Some of the common polymerization methods to obtain such materials are condensation, ring‐opening, addition, and biocatalytic‐assisted polymerization. Alongside that, processing techniques such as melt mixing/extrusion, solution castings, compression, and injection molding have also been employed for the manufacture of biodegradable polymers. While these traditional techniques are viable routes to market, there is still the need to further improve their properties to make them comparable to their petrochemical‐based counterparts. To assist with that, the production of composites and blending techniques are facile approaches that demonstrated promising improvements in their properties. Based on these aspects, this review is aimed at discussing the main types of biodegradable polymers, followed by the compositing approaches reported in the recent literature, their structure–property relationships, and biodegradability mechanisms. The first section provides an introductory overview of biodegradable polymers and their composites. The second section focuses on the most prominent polymers used in the industry. Furthermore, the fabrication techniques, along with their property and application relationships are provided with an emphasis on mechanical reinforcements and the biomedical field. Finally, some future perspectives are given to clarify some of the known challenges and, possibly, provide some insights for the reader to develop novel ideas.
Isothermal crystallization kinetics of pure and surface‐modified silica/high‐density polyethylene nanocomposites
Authors: Hojatzadeh Saeideh , Rahimpour Farshad , Sharifzadeh Esmail 
Published: December 2023

AbstractThe isothermal crystallization kinetics of high‐density polyethylene (HDPE) nanocomposites containing 0, 0.5, 0.75, and 2 wt% of pure and surface‐modified silica were evaluated at three crystallization temperatures (Tc) of 120°C, 121°C, and 122°C using differential scanning calorimetry (DSC) and applying Avrami, Tobin, and Malkin equations. According to Hoffman‐Weeks theory, the values of the equilibrium melting point () of the nanocomposites decreased with increasing nanoparticle content and were higher in the samples containing AMS nanoparticles, owing to the larger crystal. The results of all three models offered the same trend according to which the change in the crystallization temperature influenced the nucleation mechanism and the crystallization rate. It was found that a greater number of spherulites can be formed via increasing Tc from 120°C to 122°C which also decreased the crystallization rate of the nanocomposites. At the crystallization temperature of 122°C, the lowest melting temperature was recorded for the samples, attributed to the formation of more crystals with a lower thickness. Moreover, in HDPE/AMS nanocomposites, the crystallization rate was higher than that of HDPE/PSN, ascribed to the positive effect of surface modification on nanoparticles.Highlights
Increased polymer/particle compatibility and isothermal crystallization.
Evaluating the nucleation and crystallization using different models.
The impact of isothermal crystallization temperature on crystallinity.
Variation of equilibrium melting point with the nanoparticle content.
Research on the effects of jute fibers filler content and surface treatment on the mechanical properties of natural rubber latex foam
Authors: Li Yi , Du Yue , Teng Fei , Liang Ce , Gao Shuang , Zhao Zengxia 
Published: December 2023

AbstractNatural rubber latex foam (NRLF) filled with untreated and alkali/silane coupling agent‐treated jute fibers (JFs) were prepared using the Dunlop method. The JFs fillers were added at 0, 1, 3, and 5 phr. The density, crosslinking degree, and surface morphology of the untreated jute‐filled NRLF were studied, and the tensile and compression properties of the untreated and surface‐treated NRLF were compared. The results showed that the density, the modulus at 100% elongation (M100), and compression set of the untreated jute‐filled NRLF increased with increasing JFs filler content. The crosslinking degree, tensile strength, elongation at break, and recovery rate decreased with increasing JFs filler content. Regarding mechanical properties, the surface‐treated JFs‐filled NRLF exhibited higher tensile strength and M100 than the untreated group, indicating that alkali/silane coupling agent treatment enhanced the interaction between JFs and the matrix. However, the elongation at break was lower. As for the compression set and recovery rate, there was no significant difference between the two groups, indicating that alkali/silane coupling agent treatment had little effect on the compression set and recovery rate of JFs‐filled NRLF.
Covalent adaptable network offers “sustainable” closed‐loop circularity in epoxy vitrimers
Authors: Tripathi Sandeep , H Supriya , Bose Suryasarathi 
Published: December 2023

AbstractTraditional Epoxies take hours to cure before their properties can be realized and this restricts its use in applications where quick turn‐around time is imperative. Herein, we developed fast curing Epoxies (which cure within 2 h) using Vitrimer chemistries. A unique dynamic curing agent (bio‐based Schiff motif) consisting of an aldehyde (here, cinnamaldehyde) and an amine (here, mussel inspired dopamine) is used to facilitate imine exchange during the curing process and maintains the network integrity‐ a key requirement to achieve excellent structural properties in epoxy based components. By incorporating this covalent adaptable network, various epoxies were designed which can cure within 2 h. The resulting epoxy vitrimers exhibited high tensile strength (68 MPa), exceptionally high Tg (128°C), fast stress relaxation (a relaxation time of 15.2 s at 180°C) and an activation energy of 105 kJ/mol. This associative covalent adaptable network (imine exchange) also rendered the epoxies re‐processable and re‐usable and offers closed‐loop circularity in plastics. The resulting epoxy also exhibited self‐healing property triggered by the exchangeable bonds. The self‐healing behavior of this epoxy was manifested from the surface conductivity measurements wherein the conducting pathway (facilitated by spraying conducting particles on the vitrimer epoxy substrate) was restored post self‐healing in substrates containing epoxy vitrimers. In addition, the epoxies cured using this Schiff based motif dissolves in a specific solvent and can be recovered and re‐purposed. The excellent mechanical properties achieved by retaining the network integrity together with the self‐healing properties offers myriad applications for the designed epoxy cured using bio‐based Schiff motif.Highlights
Developed fast curing Epoxies that cures in 2 h using Vitrimer chemistries.
Fully bio‐based hardener was used to realize the network topology.
The dynamic exchange reaction results in re‐processability, reusable, recyclable and self‐healable that is not possible in the case of traditional epoxy.
It exhibited high tensile strength, exceptional Tg, fast stress relaxation and an activation energy of 105 KJ/mol.
A pragmatic approach to analyze the ability of ethylene‐octene copolymer in the long chain branching of polypropylene in molten and solid state
Authors: Negaresh Mohammadmahdi , Karbalaei‐Bagher Milad , Jahani Yousef , Forouzan Ali 
Published: December 2023

AbstractThe investigation of chain branching in polypropylene (PP) holds significant importance for comprehending the impact of structural modifications on the properties of PP. The utilization of ethylene‐octene copolymer (EOC) presents a valuable opportunity to examine the influence of branching density on the ability of electron beam irradiation or a chemical agent in a PP blend. The introducing long chain branches (LCB) into PP can enhance its mechanical properties, particularly impact strength. This characteristic is of particular significance in applications where the material is subjected to mechanical stress, such as automotive components or packaging materials. Blends of PP/EOC were produced using 20 and 30 wt% of EOC and 0.5 phr trimethylolpropane trimethacrylate (TMPTMA) monomer. To evaluate the efficiency of branching in both solid and molten states, irradiated samples and samples mixed with dicumyl peroxide (DCP) were selected. The rheological properties of the molten blends in shear and extensional modes were assessed, and their morphology was examined using scanning electron microscopy. The existence of LCB in all samples was confirmed through dynamic viscoelastic measurements. It was concluded that although the irradiation promoted chain scission within the backbone, which resulted in long chain branching, DCP created LCB on the backbone chains of PP through chemical reaction in the melt state. Additionally, the strain hardening constant (n) was calculated, and its value for the irradiated sample PP/EOC 80/20 was 0.19, whereas its value for this blend when employing DCP was 0.14. While the complex viscosity of irradiated blend (8764 Pa.s) was greater than that of melt state branched blend (8377 Pa.s) at 0.1 rad/s, in the higher frequencies it became smaller due to the more effective creation of long chain branches through peroxide grafting in the molten state. The results of the study verified the presence of LCB in the materials by observing longer relaxation time and strain hardening behavior.Highlights
The chain branching of PP/EOC blends was investigated in both the melt state and solid state through the presence of TMPTMA monomer.
The effectiveness of TMPTMA monomer in grafting was mostly notable in the molten state.
The steady state viscosity of LCB‐(PP/EOC) was higher in the presence of dicumyl peroxide compared to irradiated PP/EOC.
The samples containing 80 wt% of PP exhibited longer side branches compared to the sample with 70 wt% of PP according to shear and extensional rheometry.
The induced side chain branches resulting from irradiation and the use of dicumyl peroxide help increase the miscibility of the polymers to a similar extent.
Explainability and extrapolation of machine learning models for predicting the glass transition temperature of polymers
Authors: Babbar Agrim , Ragunathan Sriram , Mitra Debirupa , Dutta Arnab , Patra Tarak K. 
Published: December 2023

AbstractMachine learning (ML) offers promising tools to develop surrogate models for polymers' structure–property relations. Surrogate models can be built upon existing polymer data and are useful for rapidly predicting the properties of unknown polymers. The accuracy of such ML models appears to depend on the feature space representation of polymers, the range of training data, and learning algorithms. Here, we establish connections between these factors for predicting the glass transition temperature (Tg) of polymers. Our analysis suggests linear models with fewer fitting parameters are as accurate as nonlinear models with many hidden and unexplainable parameters. Also, the performance of a monomer topology‐based ML model is found to be qualitatively identical to that of a physicochemical descriptor‐based ML model. We find that the ML models's performance in the extrapolative region is enhanced as the property range of the training data increases. Moreover, we establish new Tg – polymer chemistry correlations via ML. Our work illustrates how ML can advance the fundamental understanding of polymer structure–property correlations and its efficacy for extrapolation problems.
Monomer ratio‐controlled polyimides with enhanced dielectric properties and thermal stabilities through crosslinking network
Authors: Huang Yung‐Jen , Lin Jin‐Wei , Lee Yueh‐Hsing , Busireddy Manohar Reddy , Chen Jiun‐Tai , Hsu Chain‐Shu 
Published: December 2023

AbstractPolyimides (PI) are considered as one of the most used materials for flexible printed circuit board substrates because of their excellent thermal stabilities, outstanding mechanical properties, and great dielectric properties. Dielectric constants (Dk) of common commercial PIs, however, are still above 3.0 (at 10 GHz), which is still substandard for high‐frequency applications. In this study, we develop thermally stable PIs with enhanced dielectric properties by structural design and crosslinking. Stiff aromatic 2,2′‐bis(trifluoromethyl)benzidine (TFMB) and soft aliphatic dimer diamines (DDA, priamine), including priamine 1074 (DDA‐1) and priamine 1071 (DDA‐2), are used as the diamines, and cyclobutanetetracarboxylic dianhydride (CBDA) is used as the dianhydride. By adjusting the ratio of the diamines, a series of PIs (PI‐1–PI‐5) with high thermal stabilities and low‐Dk values are synthesized. Among these PIs, PI‐4 synthesized by diamines with the ratio of TFMB:DDA‐1:DDA‐2 = 85:10:5, possesses relatively good performances. Therefore, PI‐4 is further chosen to be thermally crosslinked. By changing the contents of the crosslinker, triallyl isocyanurate (TAIC), crosslinked PIs (CPIs) are synthesized. The resulting CPIs have a significant improvement in thermal properties, dielectric properties, and mechanical strengths. Especially, for the CPI‐4‐30, in which 30% of TAIC is used, the glass transition temperature (Tg) increases by 20°C, the Dk decreases from 2.62 to 2.41, and the ultimate tensile strength boosts from 91.65 to 115.16 MPa. The CPIs with low Dk and high Tg values may have great potential as substrate materials for broad applications, such as microelectronics and integrated circuit packages.