The Preparation and PhysicoChemical Study of Glass,Jute and Hybrid Glass-Jute Bisphenol-C-Based Epoxy Resin Composites

Glass-PA (EC-G-PA), Jute-PA (EC-J-PA), Glass-Jute-Glass (EC-GJG-PA), Jute-Glass-Jute (EC-JGJ-PA) composites of epoxy resin of bisphenol-C (EBC) have been prepared using a hand lay-up technique at 150°C under 27.58 MPa pressure for 6 h by using phthalic anhydride as a curing agent. EC-G-PA, EC-J-PA EC-GJG-PA and EC-JGJ-PA Possess 34, 41, 27 and 21 MPa tensile strength; 34, 27, 19 and 22 MPa flexural strength; 1.9, 1.0, 1.6 and 1.3 kV/mm electric strength and 4.2 × 10¹³, 1.2 × 10⁹, 8.7 × 10¹¹ and 4.0 × 10¹¹ ohm.cm volume resistivity. Hydrolytic stability of the composites was tested against water, 10% aq. HCl and NaCl solutions at 35°C and also in boiling water. The percent water uptake, equilibrium time and diffusivity of the composites have been determined and discussed their possible applications.     

Preparation and Physico-Chemical Study of Sandwich Glass-Jute-Bisphenol-C-Formaldehyde Resin Composites

Glass-Jute-bisphenol-C-formaldehyde (Glass-Jute-BCF) sandwich composites were prepared by hand lay-up technique at 150°C under 30.4 MPa pressure for 2 h. The resin, glass and jute fiber content in the sandwich composite were 33.3, 10.4 and 56.3 wt%, respectively. 10 prepregs containing 8 inner prepregs of jute mats sandwiched between 2 outer prepregs of glass mats. Glass-Jute-BCF sandwich composite has 23 MPa tensile strength, 119 MPa flexural strength, 1.72 kV/mm electric strength and 1.25 × 10¹² ohm cm volume resistivity. Tensile strength and volume resistivity both decreased, while flexural strength and electrical strength both improved upon hybridization. Sandwich composite showed high diffusivity in water, 10% NaCl and 10% HCl solutions as compared to Glass-BCF composite. Equilibrium water absorption time is found to be 72 h in all 3 environments. Comparatively low diffusivity is observed due to silane treated glass fibers. No effect of boiling water is observed on stability of composite. Saturation time in boiling water reduced 18 times without any damage to the composite. Glass-Jute-BCF sandwich composite may be useful for low load bearing applications in construction, electrical and electronic industries as well as in harsh acidic and saline environments.     

Preparation,Mechanical and Electrical Properties and Water Absorption Study of Novel Bisphenol-C-Formaldehyde-Acrylate Treated and Untreated Jute Composites

The depolarization current spectra for polyvinyledenefluoride (PVDF), poly methylmethacrylate (PMMA), and their double-layered samples have been recorded under different polarizing conditions. When double-layered sample is polarized at 323 K with high field, a new TSDC peak is observed that is inherent in PMMA and PVDF when considered individually. This is because of the trapping charge carriers at the PVDF–PMMA interface. The space charge peak is shifted toward the lower temperature side for the PMMA and PVDF samples; however, this trend of peak shifting was not found for double-layered samples. The trapping of charge carriers in the metal polymer interface is responsible for space charge peak. This trapping of charge carriers in polymer-polymer interface is interesting, and this process is responsible for interfacial polarization in double-layered samples.     

Comparison of Water Absorption and Mechanical Behaviors of Polypropene Composites Filled with Rice Husks Ash

Composite materials were obtained by filling polypropene with raw and thermally treated rice husks at filler contents from 1 to 20%. The physicochemical properties were determined. A slight increase was observed in the tensile strength of the composites based on white rice husk ash (WRHA) and aerosil (AR) at degree of filling up to 3%. Young's modulus increased and the elongation at break and energy to break point showed a tendency to decrease for all the composites studied. The thermodynamics and kinetics of water absorption at immersion were studied in the temperature interval 25–90°C. The values of the changes in standard free energy, ΔG°, enthalpy, ΔH°, and entropy, ΔS° of adsorption were calculated. Water absorption was found to be thermodynamically difficult due to the diffusion mechanism of the process and it was accompanied by a decrease in the values of ΔH° and ΔS° with an increase in fillers contents. The effects of the amount of absorbed water, temperature, and treatment time on the composites tensile properties were estimated.     

Thermal,Mechanical and Morphological Characterization of Jute/Gelatin Composites

Jute fabrics/gelatin biocomposites were fabricated using compression molding. The fiber content in the composite varied from 20–60 wt%. Composites were subjected to mechanical, thermal, water uptake and scanning electron microscopic (SEM) analysis. Composite contained 50 wt% jute showed the best mechanical properties. Tensile strength, tensile modulus, bending strength, bending modulus and impact strength of the 50% jute content composites were found to be 85 MPa, 1.25 GPa, 140 MPa and 9 GPa and 9.5 kJ/m², respectively. Water uptake properties at room temperature were evaluated and found that the composites had lower water uptake compared to virgin matrix.     

Studies on Acrylonitrile-Butadiene (NBR) Latex-Reinforced Jute Nonwoven Fabric Composites: Chemical Resistance,Mechanical Properties,and Water Absorption

Composites were fabricated by impregnating the jute nonwoven fabric in a bath of acrylonitrile-butadiene (NBR) latex. The effects of different pickup ratios (dry-to-dry weight) of jute nonwoven fabric to NBR latex viz., 1:0.5, 1:1, 1:1.5, 1:2, and 1:2.5 on the performance of composites have been studied. The fabricated composites have been evaluated for physico-mechanical properties and chemical resistance. Percent water absorption of composites has been determined both at room temperature and boiling water. Effects of different relative humidity on the equilibrium moisture content of the natural jute nonwoven fabric-NBR composites have been evaluated.     

防霉剂对木塑复合材料吸水性能的影响研究

研究了防霉剂对木塑材料自身吸水性能的影响,以竹粉/高密度聚乙烯(HDPE)、木粉/HDPE为供试复合材料,通过向其中添加一定量的ZB-2335、WPC-GUARD及ZD-29E、ZD-4E四种防霉剂,测试不同防霉剂对木塑材料吸水性能的影响.结果表明:无论是在室温还是在60℃条件下,四种防霉剂均对竹粉/HDPE、木粉/HDPE复合材料的吸水性能无显著影响.向竹粉/HDPE、木粉/HDPE复合材料中加入不同用量的ZD-29E防霉剂,测试了ZD-29E防霉剂用量对木塑材料吸水性能的影响,结果表明:无论是在室温还是60℃条件下,不同用量ZD-29E防霉剂的加入,对供试木塑材料的吸水性能无显著影响.     

短玻纤增强PBT电击穿和力学性能的研究

以提高玻纤增强PBT材料在湿热环境下的电和力学性能为目标，研究了短玻纤品种和用量，加工助剂和加工条件的影响；探讨了干，湿态材料性能产生差异的原因。结果表明，使用直径较大（13μm)的短玻纤，PTFE的减摩和润滑作用，选用PEW作流动改性剂，控制较低的螺杆转速是有效措施，玻纤－PBT界面状况是影响干，湿态材料性能的支配因素。     

Mechanical,Water Absorption and Dimensional Stability Studies of Kenaf Bast Fibre-Filled Poly(butylene succinate) Composites

The effects of fibre loadings (10?40 wt.%) on mechanical properties, water absorption and dimensional stability of poly(butylene succinate)-filled kenaf bast fibre composites were investigated. The flexural strength and modulus of the composites increased with increasing fibre loading, while the impact strength of the composites decreased with increasing fibre loading. The higher the KBF loading was the higher absorption rate, equilibrium moisture content and the poorer dimensional stability of the composites. The poor retention and recovery of the composites from effect of water absorption were reflected by the poor flexural properties of the wet and re-dried composites after exposed to 90 days' water immersion.     

Effect of Water Absorption on the Mechanical Properties of Sisal and Jute Fiber Composites

The variation of the ultimate stress and the elastic modulus of four different natural fiber-resin matrix composites was evaluated as a function of the aging of these composites in distilled water. Their diffusion coefficients and the maximum water content were also determined by fitting the experimental data to the Fickian model for diffusion. The composites analyzed were the common jute- and sisal-polyester matrix as well as jute- and sisal-epoxy resin matrix. The overall mechanical behavior observed could be qualitatively explained by the topographic aspects generated at the fracture surfaces. The jute-epoxy composite showed the best properties over all the immersion times analyzed. A strong fiber-matrix interface was developed for this composite and is partially responsible for its better behavior. The experimental data also show that the sisal fibers are more affected by water than jute fibers.     

Comparative Studies of Mechanical and Interfacial Properties Between Jute Fiber/PVC and E-Glass Fiber/PVC Composites

Composites (50 wt% fiber) of jute fiber reinforced polyvinyl chloride (PVC) matrix and E-glass fiber reinforced PVC matrix were prepared by compression molding. Mechanical properties such as tensile strength (TS), tensile modulus (TM), bending strength (BS), bending modulus (BM) and impact strength (IS) of both types of composites was evaluated and compared. Values of TS, TM, BS, BM and IS of jute fiber/PVC composites were found to be 45 MPa, 802 MPa, 46 MPa, 850 MPa and 24 kJ/m², respectively. It was observed that TS, TM, BS, BM and IS of E-glass fiber/PVC composites were found to increase by 44, 80, 47, 92 and 37.5%, respectively. Thermal properties of the composites were also carried out, which revealed that thermal stability of E-glass fiber/PVC system was higher. The interfacial adhesion between the fibers (jute and E-glass) and matrix was studied by means of critical fiber length and interfacial shear strength that were measured by single fiber fragmentation test. Fracture sides after flexural testing of both types of the composites were investigated by Scanning Electron Microscopy.     

废纸浆/ABS复合材料的性能研究

研究了废纸浆、马来酸酐接枝苯乙烯-乙烯/丁烯-苯乙烯(SEBS-g-MAH)用量以及发泡对废纸浆/丙烯腈-丁二烯-苯乙烯(ABS)复合材料的力学性能和吸水率的影响;通过扫描电镜SEM分析了SEBS-g-MAH对未发泡和发泡废纸浆/ABS复合材料的增容效果.结果表明:废纸浆用量为30份和SEBS-g-MAH用量为20份时,未发泡和发泡复合材料的拉伸性能和缺口冲击强度都达到最佳;吸水率随纸浆用量的增加而增加,SEBS-g-MAH用量为20份时,未发泡和发泡材料吸水率都达到最低.发泡后的复合材料的拉伸强度降低,冲击性能和吸水率升高.SEBS-g-MAH能有效地改善ABS和纸浆的界面相容性.     

木质纤维/PP复合材料吸水性能研究

采用模压成型工艺制备了木质纤维/PP木塑复合材料。测试了复合材料的24h吸水率和吸水厚度膨胀率,用体视显微镜对复合材料的微观结构断面进行了观察。结果表明:木质纤维质量分数为30%,粒径为100目时,复合材料的防水性能较好。     

Optimization of Mechanical Characteristics of Short Glass Fiber and Polytetrafluoroethylene Reinforced Polycarbonate Composites via D-Optimal Mixture Design

This paper deals with the application D-optimal mixture design (DMD) integrating response surface methodology (RSM) to discuss variation of mechanical characteristics depending on injection molding during production of short glass fiber (SGF) and polytetrafluoroethylene (PTFE) reinforced polycarbonate (PC) composites. Planning of experiments was based on a D-optimal mixture design (DMD). By applying RSM analysis, a mathematical predictive model of the tensile strength and flexural strength properties was developed in terms of the mixture ratio of PC, SGF, and PTFE. In addition, analysis of variance (ANOVA) and response surface graphs were applied to identify the effect of mixture ratio of SGF and PTFE reinforced PC composites for the tensile strength and flexural strength.     

Study of Water Absorption Behavior in Wood Plastic Composites by Using Neutron Radiography Techniques

Abstract

Neutron radiography (NR) technique has been adopted to study the water absorption behavior of different kinds of wood plastic composites (WPC). The cold neutron radiography facility (CNRF) of Japan Research Reactor (JRR‐3M) was used in this work. Profiles of the absorbed water thickness of the samples are easily observed and measured from the radiography images. A small difference between NR image data and the measured data has been observed. That water absorption in these composites increases with time is clearly observed from the NR images.     

电光源用硼硅酸盐玻璃紫外截止性研究

针对电光源用硼硅酸盐玻璃的紫外截止问题进行了系统研究,利用SiO2-B2O3-Al2O3-R2O玻璃体系,以TiO2作为紫外截止剂,采用紫外分光光度法测其吸光度,根据吸光度的大小判断其紫外截止性能,并分析其影响机理.     

A Comparative Study on the Mechanical,Degradation and Interfacial Properties of Jute/LLDPE and Jute/Natural Rubber Composites

Jute fabric (hessian cloth) reinforced low-density polyethylene (LLDPE) composites (40 wt%) and solid natural rubber-(NR) based composites (40 wt%) were fabricated by compression molding. Tensile strength (TS), tensile modulus (TM) and percentage elongation at break (Eb) of jute/LLDPE composites were found to be 29, 680 MPa and 20%, and for jute/NR-based composites were also found to be 15, 122 MPa and 94%, respectively. Interfacial shear strength (IFSS) of the jute/LLDPE and jute/NR systems was investigated by using the single fiber fragmentation test (SFFT). Scanning electron microscopy (SEM) and aqueous degradation tests were also performed.     

Water Absorption Behavior and Impact Properties of Spartium Junceum Fiber Composites

This paper presents the influence of Spartium junceum (SJ) fiber content, surface treatment and temperature on the water uptake of polypropylene/Spartium junceum fiber (PP/SJ) composites. Composites specimens were dried at 70°C to reach a constant weight and then were submerged in distilled water at different temperatures, 23°C and 85°C. Water uptake of PP/SJ fiber composites was found to increase with fiber content. Impact strength properties are dramatically affected by the water absorption. Water-saturated samples present poor impact strength. The SEM micrograph of Spartium junceum fiber untreated and treated with silane (Z-6020) illustrate the reduction of roughness via surface treatment of fiber.     

微发泡PP/GF复合材料力学性能研究

采用化学发泡注塑成型的方法制备了微发泡聚丙烯/玻璃纤维(PP/GF)复合材料;结合成核理论和玻纤增强机理,研究了发泡质量对微发泡PP/GF复合材料力学性能的影响。结果表明:在PP/GF复合材料中添加5.0%纳米SiO2后,纳米SiO2对PP与GF的相容性并无太大影响,微孔发泡PP/GF复合材料的拉伸强度和冲击强度得到较大提高。     

Study on Mechanical and Dielectric Properties of Jute Fiber Reinforced Low-Density Polyethylene (LDPE) Composites

Abstract

Jute fiber (Hessian cloth) reinforced low-density polyethylene (LDPE) composites were prepared by heat press molding techniques. The mechanical properties such as tensile strength (TS), bending strength (BS), and elongation at break of the composites were studied. The enhancement of TS (33%) and BS (50%) were obtained as a result of reinforcment jute fabrics in LDPE. In order to improve the mechanical properties and adhesion between jute and LDPE, hessian cloth were each treated with 2-hydroxyl ethyl methacrylate (HEMA). The HEMA-treated jute composite showed higher tensile and bending strength compared to untreated jute composite and LDPE. Dielectric properties like dielectric constant and loss tangent (tan δ) of jute, LDPE and composites were studied. Ferro to paraelectric phase transition occurred in both treated and untreated jute composites containing more than 20% jute. Water uptake behaviors of the composite were monitored and HEMA-treated composite showed lower water absorption behavior. The adhesion nature of jute and LDPE also characterized by scanning electronic microscopy (SEM), better adhesion was observed between HEMA-treated jute and LDPE over untreated ones.