bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Fiber Volume Fraction in Fiber Reinforcement Compaction in Resin Injection Pultrusion Process
Authors: Shakya N.S. , Roux J.A. , Jeswani A.L.
Published: September 2018

In the resin injection pultrusion process (RIP), the liquid resin is injected into the continuously pulled fibers through the injection slots to cause complete wetout of the fibers. As the resin penetrates through the fibers, the resin also pushes the fibers away from the wall causing compaction of the fiber reinforcements. When the fibers are squeezed together due to compaction, the resin penetration becomes more difficult; thus a resin injection pressure below a certain pressure cannot effectively penetrate through the fibers and achieve complete wetout. However, if the resin injection pressure is too high, the fibers are squeezed together to such an extent that the fiber becomes essentially impenetrable by the liquid resin. The harder it is to penetrate through the fibers, greater is the tendency of the fibers to be pushed away from the wall and cause compaction and affect wetout. In this study, the effect of fiber volume fraction on the fiber reinforcement compaction and the complete wetout is presented.
Effects of Fluorinated Silane Coupling Agent on Properties of Microcapsules for Self-Healing Materials
Authors: Cai Xiulan , Fu Datian , Qu Ailan
Published: September 2018

Urea–formaldehyde (UF) microcapsules used as self-healing materials were facilely prepared by a sonication technique using epoxy resin (E-51) and UF resin as core and shell materials, respectively. Fluorinated silane coupling agent (KBM-7803) was used to modify the surface of the UF microcapsules. The as-prepared microcapsules were investigated by Fourier transform infrared spectroscopy, which indicated the formation of UF polymer with successful encapsulation of the core materials in UF shell and effective absorption of KBM-7803 on the surface of the microcapsules. Analysis of the mechanical properties revealed that the modification using KBM-7803 improved the tensile properties and decreased the elasticity of the microcapsules. The results of scanning electron microscopy illustrated that KBM-7803 modified microcapsules had thin shells, indicating that the microcapsules were capable of being ruptured easily which resulted in the effective release of the curing agent into the crack planes to form a polymer that bonded the crack faces and restored the structural continuity of the composite, leading to effective self-healing.
Electromagnetic Interference Shielding Effectiveness and Electrical Conductivity of Ni Coated Pcabs/Pps Composites with Reinforcement of Carbon Fibre
Authors: Sunitha J.N. , Rajesh C.S. , Rai S.K
Published: September 2018

In this study, the EMI shielding effectiveness and electrical conductivity of nickel-coated Polycarbonate Acrylonitrile-butadiene-styrene (PCABS)/Polyphenylene Sulfide (PPS) graphitic composites with reinforcement by carbon fibre were investigated. Pulverized PCABS and PPS powder particles were coated with nickel using the electroless deposition technique. Electron microscopy evidenced the uniform nickel deposition on PCABS and PPS powder particles. The conductive composites were prepared with various amounts of nickel-coated PCABS/ PPS, carbon fibre (CF) and graphite in order to increase the electrical conductivity of the matrix. Composites were found to have excellent electrical conductivities of 12 S/cm and 19 S/cm, and electromagnetic interference (EMI) shielding effectiveness of 79 dB and 87 dB respectively. Tensile strengths at break were decreased by filler addition, and both tensile and flexural moduli were increased. The resulting conductive composites could be used in applications where metals have typically been the materials of choice.
Pmma Denture Base Composites Reinforced by Nitrile Rubber and Ceramic Fillers
Authors: Alhareb Ahmed O. , Akil Hazizan Md. , Ahmad Zainal Arafin
Published: September 2018

Poly(methyl methacrylate) (PMMA) denture base composites were fabricated by incorporating nitrile butadiene rubber (NBR) particles and ceramic fillers (Al2O3, YSZ, and SiO2). PMMA powder was mixed with liquid methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EGDMA) as crosslinking agents. The different types of ceramic fillers were fixed at 5 wt.% and NBR particles in proportions of 5, 7.5 and 10 wt.%, respectively, mixed with PMMA. The impact strength (IS) increased and the fracture toughness (KIC) decreased with the increase of NBR content in PMMA matrix. The composites with Al2O3 showed better IS and KIC when compared to YSZ and SiO2 particles. It has been demonstrated that the combination of 10 wt.% NBR/5 wt.% Al2O3 produced the optimum density (1.049 g/cm3), IS (7.41 KJ/m2), KIC (2.45 MPa.m1/2) and statistically the values was significantly increased (p < 0.05).
Pressure Transient Behavior for Alternating Polymer Flooding in a Three-zone Composite Reservoir
Authors: Zhu Changyu , Cheng Shiqing , He Youwei , Tang Engao , Kang Xiaodong , Peng Yao , Yu Haiyang
Published: September 2018

Alternating polymer flooding has achieved great attractions recently in oil industry, however, the research of pressure analysis in alternating polymer flooding reservoir is rare. This work presents a numerical pressure analysis method of three-zone composite model for formation evaluation. A new numerical pressure analysis model (three-zone composite model) is established by considering diffusion, convection, shear, and inaccessible pore volume, which is based on the rheology experiments. Based on this model, the type curves are then developed and sensitivity analysis is further conducted. The type curves have seven regimes in three-zone composite model. The characteristic is the obvious upturn of pressure derivative curve in transient regime between low concentration and high concentration polymer solution. Formation parameters can be interpreted by history matching and formation evaluation can be conducted based on this model. As an important part of formation evaluation, formation damage as a result of adsorption of polymers in porous media is evaluated by comparing the interpreted permeability with the original value before polymer flooding. The field test data proves that this proposed method can accurately evaluate reservoir characteristics in alternating polymer flooding reservoirs, which emphasizes the potential application of this method in petroleum industry.
Mechanical Properties of Graphene Oxide/Polyvinyl Alcohol Composite Film
Authors: Cheng-an Tao , Hao Zhang , Fang Wang , Hui Zhu , Xiaorong Zou , Jianfang Wang
Published: September 2018

Graphene oxide (GO) was served as mechanical strengthening to prepare GO/Polyvinyl Alcohol(PVA) composite film. This was accomplished in order to explore the influence of contents of GO on the tensile strength and failure strain of GO/PVA composite film. The results showed that as the GO content increased, the tensile strength of the composite film became greater rapidly at first, and then decreased gradually. When the GO content was 20%, the film had its maximum tensile strength (59.6 MPa). This is over 500% of the tensile strength of pure PVA film. The failure strain of GO/PVA composite film decreased rapidly as the GO content increased. The enhancement mechanism of the composite can be explained by the existence of multi-hydrogen bonds between the hydroxyl (-OH) groups of PVA and oxygen-containing functional groups of GO.
Effect of Oyster Shell Powder Loading on the Mechanical and Thermal Properties of Natural Rubber/Oyster Shell Composites
Authors: Li Lefan , Zeng Zongqiang , Wang Zhifen , Peng Zheng , She Xiaodong , Li Sidong , Zhong Jieping
Published: September 2018

The oyster shell powder/natural rubber composites were successfully prepared by blending the modified oyster shell powder with natural rubber (NR). The oyster shell powder with a particle size of 209 nm were well distributed within the rubber matrix. The characteristic Fourier transform infrared spectroscopy (FTIR) absorption bands of both oyster shell powder and natural rubber were observed in the FTIR spectra of NR/oyster shell powder composites. The C-O absorption bands in carbonates of composites exhibit a shift from 1425 cm−1 to 1446 cm−1 which suggests the bonds formed among oyster shell powder, earth coupling agent and NR. The tensile strength and stress at 500% elongation increased with rising of the earth coupling agent. Composites with 1.5 parts per hundred rubber (phr) coupling agent achieved the highest mechanical properties, where an increase of 13.4% in tensile strength was found. The tensile strength and tear strength increased along with an increment of oyster shell powder. When the content of oyster shell powder attained 25–30 phr, the composites exhibited the best mechanical properties. In particular, the tensile strength and tear strength increased by 27.9% and 17.2% when compared with those of the control samples. Furthermore, the addition of the oyster shell powder leads to the improvement of thermal stability which is evidenced by an increase of 8 °C in the initial degradation temperature. The improvement of the mechanical properties and thermal stability of the composites have demonstrated that the oyster shell powder can be used as potential fillers for natural rubber.
Interfacial and Mechanical Properties of Continuous Fiber-Reinforced PP via Pre Impregnated Winding
Authors: Song Jiuqiang , Qin Yan , Chen Jia , Qin Siwen
Published: September 2018

In this paper, a continuous glass fiber-reinforced polypropylene prepreg was prepared by fiber treatment with a silane coupling agent and MAH-g-PP resin. Continuous glass fiber-reinforced polypropylene sheets were made from prepreg and PP mats by hot-pressing; they displayed exceptional performance. This paper studies the effects of maleic anhydride grafting on the polypropylene crystallinity and MAH-g-PP content in the prepreg, and the mechanical properties of the composites. The results showed that modifying PP with maleic anhydride decreased the tacticity of the polypropylene molecular chain, which reduced the crystallinity and melting point. An excellent interface formed between the polypropylene and fiber after the glass fiber was treated with a silane coupling agent and MAH-g-PP resin. The mechanical properties of the polymer materials displayed more favorable properties as MAH-g-PP content increased; the ideal MAH-g-PP content was 50%.
Effect of Heat Treatment on Curing Uniformity of Fiber Composite Laminates
Authors: Wang Xiaoxia , Wang Qinglin , Gao Linlin , Jia Yuxi
Published: September 2018

A numerical simulation procedure is presented to investigate the heat transfer and temperature distribution and then predict the curing uniformity of fiber/resin composite laminates during the hot molding process. By means of a coupled thermochemical simulation of the composite material curing process, the effects of curing temperature and heating rate on curing uniformity are investigated. Compared with the curing process with lower temperature and heating rate, the curing process with higher temperature and heating rate can cure the composites much faster but generate more uneven temperature distribution. By comparatively analyzing the influencing factors of curing non-uniformity, the curing characteristics of composites are revealed distinctly, which is helpful to understand the curing mechanism and design optimal curing cycle according to specific requirements.
Modified Silicon Nitride Nanopowder Coating and its Influence on the Dynamic Mechanical Property of Polymethyl Methacrylate Nanocomposite
Authors: Wang Xiaodong , Hu Yuan
Published: September 2018

In this study we modified nanoparticles to prepare Si3N4/PMMA nanocomposites. Surface modification of nano-Si3N4 powder was carried out by using a suitable modification agent (NDZ-102) for improving nanoparticles dispersion stability. The surface properties of Si3N4 nanoparticles were systematically investigated by Fourier transform infrared spectroscopy, thermogravimetric analysis, size distributions analyzer, surface free energy measurement and transmission electron microscopy (TEM). We concluded that 11% of NDZ-102 is the appropriate dosage of the coupling agent used to modify the surface of Si3N4 nanoparticles. Based on TGA and the spectra of FTIR, our results indicate that the coupling agent molecules are linked to the nanoparticles by chemical bonds, and that the surface of nanoparticles were coated by an organic layer. On the basis of the surface free energy experiments, it can be seen that there is an obvious improvement in the nanoparticles hydrophobicity after modification. Particle size tests and TEM reveal that the average diameter of the modified nano-Si3N4 is less than 100 nm and the nanoparticles have good dispersion in the solvent. It has also been found that the dynamic mechanical property of polymethyl methacrylate nanocomposite shows regular changes with an increasing powder content.
Medicated Multiple-component Polymeric Nanocomposites Fabricated Using Electrospraying
Authors: Wu Yong-Hui , Yu Deng-Guang , Li Jiao-Jiao , Wang Qing , Li Hai-Peng , Li Xiao-Yan
Published: September 2018

Drug-loaded hydrophilic polymeric composite (HPC) is one of the most promising biomaterials for resolving the long-standing challenge of the development of oral solid formulations for insoluble drugs. With polyvinylpyrrolidone K10 (PVP) as polymeric carrier and sodium dodecyl sulfonate (SDS) as a surface active agent, a new type of HPC was fabricated for enhancing the dissolution of quercetin using an electrospraying process. A solvent mixture consisting of acetic acid, acetone and ethanol were exploited to prepare the co-dissolving solution of quercetin, PVP, and SDS for creating HPC. Both the sprayed nanoparticles and casting film fabricated using a thermal solvent evaporation process were amorphous composites, as demonstrated by the XRD results. ATR-FTIR spectra verified that the drug and the pharmaceutical carriers had good compatibility. In vitro dissolution experiments showed that the sprayed HPC could provide an over ten-fold faster dissolution rate than the casting film. Electrospraying is a facile method for developing new kinds of HPCs for insoluble drugs.
Effect of Aminosilane Concentrations on the Properties of Poly(Lactic Acid)/Kenaf-Derived Cellulose Composites
Authors: Tee Yee Bond , Talib Rosnita A. , Abdan Khalina , Chin Nyuk Ling , Basha Roseliza Kadir , Yunos Khairul Faezah Md
Published: September 2018

To reinforce the use of kenaf-derived cellulose as a compatible plastic filler, the cellulose (C) was thermally grafted with various concentrations (5, 8, and 11 wt.%) of hydrolysed 3-aminopropyltriethoxysilane (APS). The silane-grafted cellulose (SGC) were named as SGC5, SGC8 and SGC11. C (30 wt.%) and all of the SGC were respectively melt-compounded into poly(lactic acid) (PLA) before being hot-pressed into ∼0.3 mm sheets, which is the approximate thickness of clamshell packaging. The intermolecular interaction between SGC and PLA, which was absent with C, was confirmed via Fourier Transform Infrared Spectroscopy (FTIR). PLA filled with SGC5 or SGC8 showed significant improvement in thermal, tensile, physical, and barrier properties compared with the PLA/C composite. In contrast, adverse effects were observed with the PLA/SGC11 composite. 8 wt.% of APS was concluded as the critical concentration to be thermally-grafted onto the kenaf-derived cellulose as PLA/SGC8 composite showed optimum reinforcement in tensile strength (52 MPa), crystallizability (16% crystallinity), water resistance (5.3%) and dimensional stability (3.3%), and significantly shifted oxygen barrier from medium-low range to medium range (3.2 ×10−17 m3 m/m2 s Pa). Overall, the variation in the properties of these biocomposites may extend PLA's range in food packaging applications.
Study on Effect of Surface Treating Method on Mechanical Behavior of Three Plant Fiber Reinforced Polypropylene Composites
Authors: Ma L. , He L.J. , Shao S.Y.
Published: September 2018

The surface modification effects of triethoxysilane (KH-550), methacryloxy propyl tri-methoxy silane (KH-570), and maleic anhydride grafted polypropylene (MAPP) on sawdust (SD), wheat straw (WS) and cellulose (CE) were studied by a tensile test, as well as surface morphology observation on reinforced composites. The results revealed that MAPP was the most effective coupling agent, and SD composites performed better than WS and CE. The tensile test results indicated that the optimum conditions for coupling agents were 1 wt.% for silane coupling agents and 5 wt.% for MAPP. SEM studies confirmed the tensile test results, proving that adhesion was improved with the employment of MAPP. MAPP-treated composite samples presented a prevailed fiber broken pattern which resulted in strong fiber-matrix interface bonding, whereas silane treatments did not provide an obvious enhancement in adhesion between the fiber and the matrix.
Poly(glycidyl Methacrylate) Grafted to Carbon Fiber Surface by RAFT Polymerization for Enhancing Interface Adhesion and Mechanical Properties of Carbon Fiber/Epoxy Composites
Authors: Lan Daosong , Xiong Lei , Wanyan Hongtao , Yuan Yiming , Fan Qian , Zeng Xuekai , Chen Yonglong , Cao Zhiyuan
Published: September 2018

In this study, we present a novel approach to graft a large number of poly(glycidyl methacrylate) (PGMA) chains onto the carbon fiber (CF) surface through reversible addition-fragmentation chain transfer (RAFT) polymerization. Characterization results of FT-IR, XPS and TGA demonstrated that PGMA was covalently combined with carbon fibers. The CF/epoxy composites were obtained by addition of pristine CF and CF functionalized with poly(glycidyl methacrylate) (CF-PGMA) into epoxy resin. Experiment results revealed that the grafting of PGMA chains on the CF surface could increase significantly roughness and number of active groups of CF, which enhanced interface and mechanical properties of the composites. The compression strength, tensile strength, flexural strength and interfacial shear strength (IFSS) of CF-PGMA/epoxy composites are enhanced by at least 63.1%, 37.9% 55.6% and 122.5%, respectively, compared to pristine carbon fiber/epoxy composites. This enhancement indicates that surface modification of the carbon fibers by RAFT technique is a potential method to preparing CF-reinforced polymer matrix composites with excellent mechanical properties.
Synthesis and Properties of Novel Polymers to Increase the Electrochromic Service Life of Poly(3-hexylthiophene)
Authors: Lai Cheng-Yuan , Foot Peter J. S. , Brown John W.
Published: September 2018

Poly(3-alkylthiophene)s (P3ATs) are a promising class of electrochromic materials because of their convenient processability and environmental stability. The adhesion of electroactive polymer coatings on a transparent conducting substrate is a significant factor affecting the durable colour-changing life of electrochromic devices such as visual displays and switchable windows. Traditional electrochromic coatings on transparent ITO glass electrodes often have poor cycling lifetimes, due to incompatibility between the polymers and the inorganic substrates. However, providing a covalently-bonded network between the active electrochromics and the ITO glass is an efficient method to increase the adhesion and hence to extend the service time; the research described here used Suzuki-Miyaura coupling of N-(3-trimethoxysilylpropyl)pyrrole (TMP) onto poly(3-hexylthiophene) (P3HT), as a precursor to a sol-gel reaction. The Si-O-metal network produced between the siloxane groups and metal oxide after the sol-gel reaction served to enhance the adhesion of the poly(3-hexylthiophene) onto ITO glass. With this stronger bonding, the colour-switching service time was found to be extended considerably by the observation of repeated electrochemical cycling tests. In addition, the electro-optic and electrochemical properties of copolymers with various molar substitution ratios of TMP on P3HT were investigated by cyclic voltammetry and UV-visible spectroscopy. The π-π* transition energy of P3HT increased with the degree of bromo-substitution, but diminished again after substituting with TMP. The hysteresis in electrochromic switching also became more noticeable with increased bromo-substitution on the P3HT, but it decreased when TMP was attached to the thiophene rings.
Development and Characterization of PLA/Buriti Fibre Composites – Influence of Fibre and Coupling Agent Contents
Authors: Brambilla Vanessa C. , Beltrami Lilian V.R. , Pelegrini Kauê , Zimmermann Matheus V.G. , Brandalise Rosmary N. , Zattera Ademir J.
Published: September 2018

The use of biodegradable polymers has aroused academic and technological interest directed to the replacement of conventional polymers aiming at reducing the environmental impact caused by these materials. Vegetable fibres as reinforcement elements provide gains in mechanical, thermal and degradation properties to polymer composites. The buriti fibre (Mauritia flexuosa) is an abundant crop of easy cultivation in tropical countries and its use in composites with poly(lactic acid) (PLA), can provide the development of a material with specific features, combining good mechanical properties and excellent degradation potential to the obtained composites. In this research, PLA and buriti fibre composites were developed with the use of triacetin as coupling agent. For a 30% content by mass of fibre, the results showed that the mechanical properties of the composites were similar to those of neat PLA. This was attributed to the fibre/matrix interaction observed by the SEM analysis and to an increase in crystallinity assessed by thermal properties.
Enhancing Fatigue Life of Filament Winding Laminar and Curved Pipes Containing Carbon Nanotubes, and Their Fatigue Failure
Authors: Taşyürek Mustafa , Tarakçioğlu Necmettin
Published: September 2018

In this study, the fatigue life of glass fibre-epoxy matrix material produced by the filament winding composite pipes and matrix material reinforced with multi-walled carbon nanotubes (MWCNTs) nanocomposite filament winding tubes were studied experimentally under the influence of internal pressure. Glass-reinforced plastic (GRP) pipes which were reinforced with carbon nanotubes were tested in the conditions of an open-ended test. The winding angle of test specimens was ±55° and they had six layers. During all the experiments, the fatigue life effect of reinforced carbon nanotubes was investigated. Unreinforced glass, as a reference material, was compared with reinforced plastic with the addition of nano-reinforced material using two different rates of 0.5% and 1%. Fatigue tests of specimens have been carried out in accordance with ASTM D-2992. Later on, the results obtained by determining the material properties with the reinforcement of carbon nanotubes GRP pipes were evaluated. As a result of this study, it has been found that MWCNTs reinforcement increases the fatigue life of the GRP tubes. Inter-laminar fracture strength was developed via the mechanical locking of MWCNTs. The critical MWCNTs usage value was between 0.5% and 1%.
Application of Taguchi Method for Optimizing of Mechanical Properties of Polystyrene-Carbon Nanotube Nanocomposite
Authors: Farbodi Maryam
Published: September 2018

Carbon nanotube (CNT) was selected as reinforcement agent to improve the mechanical properties of polystyrene (PS). PS–CNT nanocomposite was prepared by mixing CNT with a solution of PS. Taguchi experimental design method was used to determine the optimal conditions for preparation of the nanocomposite. The effects of six factors including the type of CNT (A), type of solvent (B), type of PS (C), drying temperature of nanocomposite film (D), the percentage of CNT (E) and duration of mixing after adding CNT (F) were investigated at different levels. The tensile strength values of PS-CNT nanocomposite films were used as the responses for the analysis of data using signal to noise (S/N) method. Using this method, the optimum conditions were obtained as: the type of CNT: functionalized single walled CNT (SWCNT), the percentage of SWCNT: 1.5%, the type of solution: tetrahydrofuran, the type of PS: GPPS 1460, drying temperature: 25 °C, duration of mixing: 1 hour. Based on the obtained values, the order of the effect of factors was CEADBF. The most effective and the least effective factors were C and F, respectively. The calculated F-ratio of each factor showed that at 95% confidence interval, the F values for all factors except factor F have significant effects on the response values. Also, the functionalization of the CNTs surfaces by –OH and –COOH groups confirmed by FTIR and SEM techniques.
Dry Slide Wear Behavior of Graphite and SiC, TiO2 Filled the Unidirectional Glass-Epoxy Composites
Authors: Madhanagopal A. , Gopalakannan S.
Published: September 2018

This study determines the friction and the wear properties of the unidirectional glass epoxy composite with Gr, SiC TiO2 powder by using pin on disk apparatus. This tribological data is obtained in dry sliding condition for a constant sliding time of 30 minutes. Test specimens are prepared using hand lay-up process and by varying the different (2, 5, 7) percentage each of graphite and SiC, TiO2 particles addition for the combination of fiber and matrix. The tests are performed by varying the operating parameters of contact pressure (p) and velocity (v). The composites (2% 5%, and 7%) are worn by dry sliding at the steel counter face under ambient conditions. The coefficient of friction reaches maximum of 0.78 at 2 kg load, 2 m/s velocity with testing time duration of 24 min. whereas 5%, 7% sample shows the coefficient of friction 0.28, 0.25 respectively. The specific wear rate value drops to 0.79 (mm3/N-m×10−6) at 2 kg load at 2 m/s velocity for the 5% specimen. The maximum reduction in the specific wear rate at 3 kg load, 1m/s velocity is 32.7 percentages, 5.63 percentages for the 5,7 percentage specimen compared to 2% specimen for the graphite and SiC, TiO2 particle filled composite specimen respectively. The SEM images are also taken to support the results.
Fabrication and Characterization of A356-Basalt Ash-Fly Ash Composites Processed by Stir Casting Method
Authors: Venkatachalam G. , Kumaravel A.
Published: September 2018

This paper presents the characterization of A356 composite reinforced with fly ash and basalt ash produced by stir casting method. Aluminium metal matrix composites (AMC) are used in wide variety of applications such as structural, aerospace, marine, automotive etc. Stir casting is cost effective manufacturing process and it is useful to enhance the attractive properties of AMCs. Three sets of hybrid AMC are prepared by varying the weight fraction of the reinforcements (3% basalt + 7% fly ash, 5% basalt + 5% fly, 7% basalt + 3% fly ash). The effect of reinforcements on the mechanical properties of the hybrid composites such as hardness, tensile, compressive and impact strength were studied. The obtained results reveal that tensile, compressive and impact strength was increased when weight fraction of fly ash increased, whereas the hardness increases when weight fraction of the basalt ash increased. Microscopic study reveals the dispersion of the reinforcements in the matrix.
An Experimentation of Chemical and Mechanical Behaviour of Epoxy-Sisal Reinforced Composites
Authors: Yuvaraj G. , Kumar Hemanth , Saravanan G.
Published: September 2018

In this work the variation of mechanical properties like tensile, impact and chemical resistance properties of randomly oriented sisal/glass fibre reinforced hybrid composites with different fibre ratios (50:50,45:55,40:60,30:70) was studied. Hand lay up method is used for making the composites with epoxy resin. The result shows that increase in chemical, impact properties of composites with increase in fibre loading. Also it was observed that significant improvement in tensile properties of hybrid composites by alkali treatment.
The Effect of Fibers Loading on the Mechanical Properties of Carbon Epoxy Composite
Authors: Solomon Blaise , George Davis , Shunmugesh K. , Akhil K.T.
Published: September 2018

Carbon fiber reinforced epoxy composites are having greater acceptance in industries as well as for researches and engineers due to the inherent properties. In this paper the change in mechanical properties like tensile strength and hardness are studied by changing the percentage composition of carbon by 30%, 35% and 45% in the carbon epoxy composite. Composite is manufactured by vacuum suction method.
Synthesis of Chitosan-Polyvinyl Alcohol Copolymers for Smart Drug Delivery Application
Authors: Mulchandani Neha , Shah Nimish , Mehta Tejal
Published: September 2018

Chitosan is a natural polymer obtained from exoskeletons of crustaceans and polyvinyl alcohol (PVA) is a synthetic polymer which has excellent film forming ability along with non-toxic nature. The current work focuses on synthesizing a smart polymer by copolymerization of natural and synthetic polymers and exploring its applications in drug delivery. The copolymers were blended in different ratios and were synthesized using ammonium ceric nitrate as initiator and glutaraldehyde as a crosslinking agent which were converted to films by casting method. Amoxicillin, as a model drug was incorporated to the copolymerized films to study the in-vitro drug release. The films obtained were evaluated by varying the pH to study the pH responsive nature of films. Drug release studies were performed to obtain the release profile of drug; water uptake capacity of the copolymerized film were measured to determine the swelling behaviour of the films. The films were further characterized using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Differential Scanning Calorimetry (DSC) to identify the structural and morphological changes along with thermal transitions. The results indicate that the synthesized copolymers are pH responsive in nature having great potential for application in controlled and targeted drug delivery.
Effect of Na+ and Ca2+ on the Thermal Degradation of Carboxymethylcellulose in Air
Authors: Tan Liwen , Shi Ran , Ji Quan , Wang Bingbing , Quan Fengyu , Xia Yanzhi
Published: September 2018

Carboxymethylcellulose (CMC), including the acid form (CMC-H) and salt forms (CMC-Na, CMC-Ca), were prepared for the survey of thermal degradation and the CMC-H was obtained by acidifying CMC-Na with HCl. An online-coupled thermogravimetric (TG)-FTIR evolved gas analysis instrument was used to identify and monitor the evolution of gaseous products during the thermal degradation of CMC in air. The thermal degradation characteristics of CMC-H and salt forms CMC-Na, CMC-Ca of carboxymethylcellulose were compared to determine the effect of Na+ and Ca2+ counter-ions on CMC thermal degradation in air. From the TG and DTG curves, thermal degradation of the samples occurred in three stages. During the second stage (200–410 °C) major degradation occurred, accompanied by a large weight loss. The 3D FTIR absorbance spectra and Gram-Schmidt curves of the evolved gases were obtained. In compounds CMC-Na and CMC-Ca, the initial degradation temperature is higher, the rate of CMC degradation increases, and the weight loss in the temperature range 200–410 °C decreases. These samples also catalyse the stable intermediate products in the temperature range 410–600 °C.
Analytical Modelling of Textile Parameters and Draping Behaviour of 2D Biaxial Braided Sleevings
Authors: Schillfahrt Christian , Schledjewski Ralf
Published: September 2018

Biaxial braided sleevings are commonly used for producing hollow complex-shaped composite parts through bladder inflation moulding. To enable feasibility analyses, part design and the prediction of mechanical properties of the resulting fibre-reinforced component, various geometrical and weight-related parameters of the braided fabric in its draped state must be known, such as fibre orientation, fibre volume fraction and areal weight. In the present work, a comprehensive analytical model describing fabric formation, preform architecture and weight as well as the change of relevant textile parameters of a biaxial braided sleeving during draping is established. The principal modelling approach is based on sporadic investigations found in literature and was substantially expanded to compile an extensive collection of relationships for the utilisation in a sleeving-on preforming process. Furthermore, a critical overview about the state of the art in the area of geometrical modelling of tubular 2D braided structures and a comparison of the identified procedures in regard to the desired application is given.
Vinyl Ester Resin Modified with Acrylated Epoxidised Soybean (AESO) and Linseed (AELO) Oils: Effect of Additional Urethane Crosslinking
Authors: Grishchuk S. , Karger-Kocsis J.
Published: September 2018

Bisphenol A-based vinyl ester resin (VE) was modified with acrylated epoxidised soybean and linseed oils (AESO and AELO, respectively) in 10 wt.%. The double bond/epoxy ratio in these functionalised vegetable oils was practically the same, i.e. 30/70%, allowing us to deduce effects caused by the different unsaturations in the parent oils. The crosslink density of the resins was enhanced by adding polyisocyanate. The glass transition temperature (Tg) of the hybrids was determined by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). Resistance to thermal degradation was assessed by thermogravimetric analysis (TGA). The fracture toughness and energy (Kc and Gc, respectively) were determined on compact tension specimens at room temperature. Incorporation of AESO and AELO reduced the Tg of VE along with slight reductions in the Kc and Gc data. The Tg reduction was less for AELO than AESO which was attributed to the higher functionality of AELO compared to AESO. Urethane crosslinking of VE (VEUH) prominently enhanced the Tg. Modification of VEUH with AES(L)O enhanced the Tg due to additional crosslinks. Urethane hybridisation was associated with a strong decrease in both Kc and Gc compared to those of the parent VE. Kc and Gc of VEUH did not change practically as a function of blending with AES(L)O. Incorporation of AES(L)O reduced the resistance to thermal degradation of both VE and VEUH.
Isocyanate-functionalised Montmorillonite as a Reactive Asphalt Modifier
Authors: Zhang Dengke , Xiao Xinyan , Cui Ying
Published: September 2018

Sodium montmorillonite was functionalised by isophorone diisocyanate (IPDI) and organic montmorillonite was functionalised by hydrogenated diphenylmethane diisocyanate (HMDI). Reaction between montmorillonite (MMT) and IPDI/HMDI caused the interlayer space of MMT to increase from 1.41 nm to 1.95 nm and 2.08 nm to 2.42 nm, respectively, and the resulting grafted –NCO groups led to a suitable reactive modifier. In order to improve the high-temperature performance and UV aging resistance of the asphalt binder, asphalt modification was carried out by chemical reaction between –NCO groups and some polar groups (mainly –OH) of asphalt. The results showed that the interlayer space enlarged and exfoliated structure was formed due to the introduction of functionalised MMT (IPDI-HMMT-85 or HMDI-OMMT-80) into the asphalt. The as-prepared IPDI-HMMT-85 and HMDI-OMMT-80 modified asphalts, with a maximum softening point of 57.0 °C and 62.2 °C, initial decomposition temperature of 363 °C and 374 °C, respectively, possessed good storage stability, and were superior to Na-MMT modified asphalt and OMMT modified asphalt in terms of high temperature and UV aging properties.
Thermal Diffusivity of Copper/Linear-low-density Polyethylene Composites
Authors: Carson James K. , Alsowailem Mohamed
Published: September 2018

The thermal diffusivities of copper/linear-low-density polyethylene (Cu/LLDPE) composites were measured relative to the thermal diffusivity of pure LLDPE. The relative thermal diffusivities were similar to those obtained for copper/high-density polyethylene composites, but were noticeably different from estimated values derived from thermal conductivity, density and specific heat capacity data for Cu/LLDPE from the literature. The thermal diffusivity of the composite material initially decreased below that of the pure polymer with the addition of a small amount of copper, before increasing above it as more was added. There would appear to be marginal or no benefit from adding less than about 15 to 20% metal by volume to a polymer, since the relative increase in thermal diffusivity only becomes significant for greater volumes.
The Mechanical and Optical Properties of Injection-moulded PMMA, Filled with Glass Particles of a Matching Refractive Index
Authors: Wildner Wolfgang , Drummer Dietmar
Published: September 2018

In this paper, the optical and mechanical properties of injection-moulded plates (thickness: 1 mm) made of poly(methyl methacrylate) (PMMA) and glass particles as filler with a matching refractive index are investigated. Tests show that the orientation resulting from the injection moulding process greatly affects the tensile strength and elongation at break, whereas the elastic modulus merely depends on the filling degree, which is investigated up to 13 vol.%. In terms of the optical properties, the specimens’ haze depends on the difference in the refractive index between a glass and polymer. However, the absolute value of haze increases with increasing filling degree and decreasing particle size. Surface defects resulting from the injection moulding process were found to be the primary reason for this haze, even with identical RI between PMMA and glass.
Synthesis of Polyaniline-TiO2 Nanocomposites and Their Application in Photocatalytic Degradation
Authors: Jumat Nur Aziera , Wai Phang Sook , Ching Juan Joon , Basirun Wan Jefrey
Published: September 2018

Photocatalyst involving conducting polymer doped with titanium dioxide, TiO2 hold a great efficiency for photocatalytic application. In present study, polyaniline (PAni) with different TiO2 content (10%, 20%, and 40%) has been successfully synthesized through template free method. Ultraviolet-visible (UV-vis), Fourier Transform Infrared (FTIR), Raman, and X-ray Powder Diffraction (XRD) characterizations of PAni-TiO2 nanocomposites confirmed the chemical structure of polymer composites was intact after doped with TiO2. Field Emission Scanning Electron Microscope (FESEM) investigation of PAni-TiO2 nanocomposites revealed the formation of nanorod/nanotube. PAni-TiO2(10%) showed the highest conductivity 2.48 × 10−2 S/cm as compared to those with 20% and 40% of TiO2 content. Photocatalytic properties of PAni-TiO2 were examined by degrading Reactive Black 5 (RB5) dye under visible light irradiation. PAni-TiO2(10%) showed the greatest degradation (96%) than that of TiO2 (10%). Due to synergistic effect between PAni and TiO2, it is capable of absorbing visible light more efficiently and decreasing the process of electron hole recombination. Photoluminescence (PL) analysis proved low efficiency of electron hole recombination of PAni-TiO2.
Synthesis of Water-soluble Polyaniline by Using Different Types of Cellulose Derivatives
Authors: Hussin Hazira , Gan Seng Neon , Mohamad Sharifah , Phang Sook Wai
Published: September 2018

Pure polyaniline (PAni) is insoluble in water. Water-soluble complexes of PAni with different of cellulose derivatives were successfully synthesized by using chemical oxidation polymerization of aniline in aqueous solution of cellulose derivatives. In this study, cellulose derivatives such as methylcellulose (MC), hydroxypropyl cellulose (HPC), and hydroxypropyl methylcellulose (HPMC) had been used as a steric stabilizer, aniline (Ani) as a monomer with hydrogen chloride (HCl) as an acidic dopant, and ammonium persulfate (APS) as an initiator. The chemical structure of PAni complexes were confirmed by using Fourier Transform Infrared Spectroscopy (FTIR). The interactions of PAni and cellulose derivatives were observable through Ultraviolet-Visible Spectroscopy (UV-Vis) in the wavelength range of 300 nm to 900 nm. The Standard Four-Point Probe Method was used for the conductivity measurements. In the electrical conductivity measurement, PAni in toluene was used as a control. The result showed that water-soluble PAni-cellulose derivatives gave higher conductivity value (9.47 × 10−2 – 1.87 × 10−1 S/cm) than the pristine PAni (1.60 × 10−3 S/cm).
Red Seaweed Pulp as a Separator in Rechargeable Al-anode Battery
Authors: Izazi A.A. , Juan J.C. , Lai C.W. , Phang S.M.
Published: September 2018

The depletion of non-renewable energy resources, has simultaneously increased the demand for energy storage system like battery. Many efforts have been made to improve the performance of battery such as high concentration of electrolyte, high power density of electrodes and high ion selective separator or membrane. The application of a biomass-derived as a separator have emerged as tantalising alternatives to liquid and synthetic polymer electrolyte for battery. The motivation is clear because of the corrosive, hazardous and leakage of liquid electrolyte usage; non-biodegradable and insolubility of synthetic polymer electrolyte in certain solvents. Due to environmental concern and sustainability, red seaweed-pulp is a good candidate to be used as a separator for battery. The SEM image revealed that morphology of red seaweed consists of 20–30% solid material (endofibre), which consists of small, regular and hollow fibre. These characteristics enable the pulp to absorb and retain the wettability of electrolyte and contribute high ion conductivity of battery. In this study, novel battery, a separator made from red seaweed-pulp, is comprised of aluminium plate (anode), graphite plate (cathode), and sodium chloride (electrolytes) that have been developed. This red seaweed pulp-based battery has shown a very good electrochemical potential from 2.5 to 3.0 V, maximum capacity up to 6 mAh, and the charge-discharge can withstand up to 10 cycles. In summary, red seaweed pulp can be a potential material for energy storage system like battery.
Application of Fiber Bragg Grating Sensor coated with Polyaniline as an optical Sensor for chloroform detection
Authors: Ahad Irma Zulayka Mohamad , Harun Sulaiman Wadi , Gan Seng neon , Phang Sook Wai
Published: September 2018

Fiber Bragg Grating (FBG) sensor coated with PAni was designed as a sensing device in chloroform detection. PAni thin film was synthesized through chemical oxidation method by using aniline (Ani) as a monomer, ammonium persulphate (APS) as an initiator and dioctyl sodium sulfosuccinate (AOT) as a dopant. The chemical structure of PAni thin film was confirmed by using Fourier transform infrared (FTIR) and ultraviolet-visible (UV-Vis) spectrometer. The conducting behaviour of PAni thin film (1.157 × 10−2 S/cm) was determined by using four-point probe measurement. In the optical sensor part, FBG was etched in hydrofluoric acid solution (48% HF) to remove the cladding layer on fiber before coated with PAni. The response of this sensor was monitored based on the different of Bragg wavelength shift at ∼1557 nm in an optical spectrum analyzer (OSA) detector. PAni-coated FBG significantly increased in the Bragg wavelength shift (sensitivity = 0.0009) compared with uncoated FBG (sensitivity = 0.0002). The interaction between PAni and chloroform was significantly confirmed by the “polaron peak ratio” (Pf/Pi) and “quinoid and benzenoid peak ratio” (IQ/ IB) through UV-vis and FTIR spectroscopy analysis. In this study, FBG sensor coated with PAni thin film had been found as an efficient sensor in chloroform detection with fast response time (7 s).
Isolation and Characterisation of Cellulose Nanowhiskers from Microcrystalline Cellulose Using Mechanical Processing
Authors: Borsoi Cleide , Ornaghi Heitor L. , Scienza Lisete C. , Zattera Ademir J. , Ferreira Carlos A.
Published: September 2018

In this study, the production of cellulose nanowhiskers (CNW) from microcrystalline cellulose (MCC) by a mechanical grinding process in a super mass colloider was evaluated. MCC and CNW samples were evaluated by thermogravimetric analysis (TGA), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The stress/strain characterisation of the films was performed by dynamic mechanical equipment. The morphological analysis showed the formation of a nanowhiskers/nanoscale structure in the CNW sample. The FTIR analysis of the CNW sample showed absorption band that is characteristic of cellulose. The XRD analysis indicated a small decrease in the crystallinity index and crystallite size, although the cellulose type-I structure was maintained. No changes were observed in the thermal stability of the CNW sample after the mechanical grinding process until 350 °C. A greater increase in the Young modulus was observed for the CNW sample.
Effect of Thermoplastic Polyurethane-Modified Silica on Melt-Blended Poly(Lactic Acid) (PLA) Nanocomposites
Authors: Lai Sun-Mou , Li Pei-Wen
Published: September 2018

3-aminopropyltriethoxysilane (APTES) was used as a coupling agent to graft thermoplastic polyurethane (TPU) onto a nanosilica surface. The modification of TPU on the surface of silica nanoparticles was confirmed by FTIR, NMR, ESCA and TGA assessment. The grafting degree of TPU onto the silica was about 7.3%. The incorporation of surface-modified silica (TAS50) into poly(lactic acid) (PLA) induced the nucleation of PLA, giving a higher crystallisation peak temperature, which would be advantageous for fast processing cycles in the commercial moulding process. With pristine silica incorporated into PLA, the variation in the cold crystallisation and melting temperatures was limited. However, for the surface-modified silica filled PLA, a lower cold crystallisation temperature at 112.1 °C and a shift of melting temperature from Tm1 to Tm2 at 167.7 °C were observed. The cooling rate also played an essential role in the derived crystalline forms. The tensile strength of the composite containing modified silica was slightly higher than that with the pristine silica, even though both showed similar degrees of silica dispersion from the morphology observation. For the surface-modified silica composite, the optical transmittance was higher than that of unmodified silica case. This finding implies the significance of the surface modification.
Preparation and Curing Behaviour of Epoxy Based Film for Moderate Temperature Prepreg
Authors: Yao Jiangwei , Zhan Haihua , Zou Zhuanyong
Published: September 2018

Bisphenol A epoxy resin and an acid anhydride [chosen from methyltetrahydrophthalic anhydride (Me-THPA), methylhexahydrophthalic anhydride (MHHPA) and methyl nadic anhydride (MNA)] were used to prepare epoxy films for hot melt prepreg. The effects of film composition, i.e. type and amount of epoxy resin, curing agent and curing catalyst, were investigated to develop a moderate temperature prepreg, and orthogonal experiments were used to investigate the effect of film composition on the curing behaviour of the epoxy resin film, and to determine the optimal formulation. The most favourable formulation film was cured at 100 °C for 2 h, and its curing degree was characterised by FTIR spectroscopy.