高温高压湿热处理对环氧树脂复合材料电性能的影响

本文研究了多官能度环氧树脂（WHUT—170）、TDE-85和E-51环氧树脂／玻璃纤维复合材料经高温高压湿热处理后的电学性能。结果表明：WHUT-170复合材料具有高的湿热绝缘性能,样品在175℃、140MPa的水压下处理2h后,复合材料的体积和表面电阻率分别为1．1×10^10Ω·cm和5．0×10^8Ω,均比TDE-85和E-51树脂复合材料的高出1个数量级;WHUT-170复合材料的介电常数和介电损耗明显低于其它体系。     

玻纤对湿热环境下的环氧复合材料拉伸性能的影响

为了研究湿热环境下玻璃纤维对环氧复合材料拉伸性能的影响,建立试验模型,以不同浸润剂配方生产的相同单丝直径及TEX值的玻璃纤维进行浸胶制样,样条在95℃下1%浓度的NaCl溶液中浸泡24 h、72 h后,样条拉伸强度变化,从而得出玻璃纤维对在湿热环境下环氧复合材料拉伸性能的影响,即选用合适的偶联剂生产的玻璃纤维,对复合材料湿态拉伸强度有明显的提升。     

树脂含量对碳布/环氧复合材料力学性能的影响

主要研究了不同树脂含量下，碳布／环氧复合材料的径向拉伸和纬向压缩性能，并初步探讨了树脂含量对复合材料拉伸、压缩性能的影响机理。试验结果表明：树脂含量对复合材料力学性能的影响较大，当树脂质量含量在42％－45％之间时，拉伸、压缩性能较好。     

顺丁橡胶/环氧树脂橡塑复合材料的制备及性能研究

采用机械共混制得顺丁橡胶(BR)/双酚A型环氧树脂(E-44)两网型橡塑复合材料。考察了橡胶硫化体系与环氧树脂固化体系的相互影响及环氧树脂比例对顺丁橡胶/环氧树脂复合材料结构及力学性能的影响。结果表明:橡胶硫化体系加速了环氧树脂的固化。SEM与DSC分析结果表明顺丁橡胶与环氧树脂形成了两网结构。随着环氧树脂比例的增加,拉伸强度、撕裂强度、100%定伸应力、硬度逐渐增强,扯断伸长率逐渐下降。     

The Effect of Fibre Surface Treatment on the Failure of Continuous Carbon Fibre/Epoxy Resin Composites

The failure mechanisms of a composite, consisting of continuous, aligned, high strength, polyacrylonitrile (PAN) based carbon fibre in an epoxy resin, under uniaxial tension, have been studied. In order to study the effect of the interphase/interface strength, six different levels of an electrochemical fibre surface treatment were used. Single tows containing approximately 12,000 treated carbon fibres were impregnated to produce composite rods with a fibre volume fraction of 0.55. Lengths of this impregnated tow were also set in the centre of glass-fibre/epoxy resin composite coupons which were used to study the mechanisms of failure of the embedded tows. Acoustic emission was used to monitor all samples and bundle failure was found to occur after a build-up of sub-critical damage events as previously modelled.¹ Microdebond tests demonstrated an initial increase of interfacial strength which levelled out at the higher levels. In impregnated samples with high surface treatments, catastrophic failure occurred with the crack propagating approximately perpendicular to the fibre direction. However, in samples with lower fibre surface treatments, longitudinal splitting (not accounted for in current models), occurred, meaning that a greater length of composite was involved in the final failure process. Acoustic emission has been shown to have an approximately direct relation with the predicted number of single fibre breaks in composite test-pieces; however, there was no significant difference attributable to the different surface treatments. The hybrid test coupons allow a detailed assessment of the failure mechanisms within the impregnated carbon tow. The failure strains of the embedded tow is some 5% higher than that of unsupported tow. The Weibull modulus is of the same order.     

The Effect of Fibre Surface Treatment on the Failure of Continuous Carbon Fibre/Epoxy Resin Composites

The failure mechanisms of a composite, consisting of continuous, aligned, high strength, polyacrylonitrile (PAN) based carbon fibre in an epoxy resin, under uniaxial tension, have been studied. In order to study the effect of the interphase/interface strength, six different levels of an electrochemical fibre surface treatment were used. Single tows containing approximately 12,000 treated carbon fibres were impregnated to produce composite rods with a fibre volume fraction of 0.55. Lengths of this impregnated tow were also set in the centre of glass-fibre/epoxy resin composite coupons which were used to study the mechanisms of failure of the embedded tows. Acoustic emission was used to monitor all samples and bundle failure was found to occur after a build-up of sub-critical damage events as previously modelled.¹ Microdebond tests demonstrated an initial increase of interfacial strength which levelled out at the higher levels. In impregnated samples with high surface treatments, catastrophic failure occurred with the crack propagating approximately perpendicular to the fibre direction. However, in samples with lower fibre surface treatments, longitudinal splitting (not accounted for in current models), occurred, meaning that a greater length of composite was involved in the final failure process. Acoustic emission has been shown to have an approximately direct relation with the predicted number of single fibre breaks in composite test-pieces; however, there was no significant difference attributable to the different surface treatments. The hybrid test coupons allow a detailed assessment of the failure mechanisms within the impregnated carbon tow. The failure strains of the embedded tow is some 5% higher than that of unsupported tow. The Weibull modulus is of the same order.     

钢渣对碳纤维水泥基材料温敏性能的影响

通过试验研究了钢渣对碳纤维水泥基材料在升温和降温过程中的Seebeck系数及电阻率的影响。研究结果表明：在碳纤维水泥基材料中掺入钢渣,可以提高水泥基材料Seebeck系数,随着钢渣掺量的增加,碳纤维水泥基材料的Seebeck系数先增大后减小;电阻率随着钢渣掺量的增加而减小,并且存在渗流现象。     

碳纳米管/石墨烯杂化材料改性环氧树脂研究

采用物理法和化学多步法合成了碳纳米管/石墨烯杂化材料,通过红外光谱表征证明杂化材料的成功合成,通过沉淀实验表明化学多步法合成的碳杂化材料具有良好的分散性和分散稳定性。将碳纳米杂化材料按照质量分数0.3%添加到环氧树脂(EP)中制备复合材料,对复合材料的拉伸强度和断裂韧性进行表征,并通过扫描电子显微镜对复合材料的断面进行表征。结果表明,碳纳米管/石墨烯杂化材料对EP的增强增韧效果较好,尤其是化学多步法合成的杂化材料改性EP复合材料,其拉伸强度最大,曲线积分面积最大,弹性模量最小,韧性最好。这可能要归因于化学多步法合成的杂化材料具有更为稳定的三维结构,可以更好地承担和转移外部载荷。     

Thermal Properties of Organic-inorganic Hybrid Composites Based on Multi-Epoxy Silsesquioxane and Epoxy Resin

The multi-epoxy cubic silsesquioxane (SSQE) was successfully introduced into epoxy resin (EP) and formed the organic-inorganic EP-SSQE hybrids. The hybrids were cured by 4,4′-diaminodiphenylsulphone (DDS) and the Fourier transformation infrared (FTIR) spectra were used to monitor the cured reaction of the hybrid, and the results showed that the hybrids could be cured thoughtfully without influence the cubic silsesquioane structure. The thermal properties of the hybrid such as the heat distortion temperature (HDT), the glass transition temperature Tg and the thermal decomposing property were studied. The results showed that the hybrids had the higher thermal properties than that of the pure epoxy resin for the introducing of multi-epoxy cubic silsesquioxane.     

加料顺序对炭黑/NR相互作用及性能的影响

研究了加料顺序对炭黑/NR间相互作用及胶料性能的影响。结果表明,配方相同时,采用先加小料后加炭黑的加料顺序可使混炼过程能耗最低,混炼胶加工性能较好,综合物理机械性能较好;加料顺序对交联密度基本没有影响;在混炼过程中,加入小料会迅速降低胶料扭矩值,起到增塑作用,有利于分散;提前加入炭黑会增强炭黑/NR间相互作用,生成较多结合橡胶。     

高性能PAN基碳纤维及其复合材料在航天领域的应用

对高性能PAN基碳纤维的发展历程、现状以及以其为增强体的复合材料进行了综述,并对高性能PAN基碳纤维增强复合材料在航天领域的主要应用情况进行了介绍,最后对我国高性能碳纤维复合材料的现状及发展重点进行了探讨.     

碳系填充环氧树脂复合材料导电性能研究进展

以逾渗理论、隧道效应理论和场致发射效应理论为例分析介绍了填充复合型导电高分子材料的导电机理;以炭黑、碳纳米管、石墨烯填充环氧树脂复合材料为例,综述了影响复合材料导电性能的主要因素,并重点介绍了相关研究人员在改善碳系材料分散性、降低复合材料渗流阙值等方面的研究进展。     

碳纳米管/聚合物复合材料研究和应用进展

碳纳米管的发现引起科学界及产业界的极大重视,大量的研究集中在碳纳米管的合成、生长机理、物理性能的表征等方面。随着碳纳米管合成、提纯、化学修饰等领域的研究不断取得进展,碳纳米管/聚合物复合材料的研究已成为世界科学研究的热点。综述了碳纳米管/聚合物复合材料研究在机械、电学、光学性能等方面所取得的进展与应用。     

碳纤维布表面处理对酚醛树脂复合材料力学性能的影响

以碳纤维布(CB)为增强相,丁苯橡胶为增韧剂,酚醛树脂(PF)为基体,通过模压成型工艺制得了PF/CB复合材料,研究了CB表面处理方式、丁苯橡胶含量及加工成型温度对PF/CB复合材料的界面结合及力学性能的影响。结果表明,丙酮处理CB、氧化处理CB及加工成型温度的提高都能改善纤维与基体的结合程度,提高界面结合力。但氧化处理CB随着加工成型温度的提高,易断裂,对复合材料的增强作用有所减弱。丁苯橡胶加入量为12%时PF的加工及冲击性能为最佳。     

碳纤维水泥基复合材料压敏性的灵敏度及机理分析

采用阶梯循环加卸载方式,对碳纤维水泥基复合材料在不同应力下压敏性的变化进行试验,提出压敏性的灵敏度概念,对比了未经烘干与经烘干后两种情况下压敏性的灵敏度差异,试验结果表明:未经烘干的碳纤维水泥基复合材料呈现正压敏特性,而烘干后的材料呈现负压敏特性,但两者压敏性的灵敏度均随受压应力的增加而减小,并且经烘干后,材料压敏性的灵敏度随受压应力增加而衰减的速度比未经烘干材料的衰减速度慢.应用隧穿效应和电容效应共同作用机理能较好的分析试验现象.     

不同的木粉处理方法对木塑复合材料性能的影响

采用不同的相容剂对木粉进行表面处理,与聚丙烯按一定比例,经双螺杆挤出机熔融挤出造粒后,制成术塑复合材料,并测试了复合材料的各项力学性能。研究发现,甘油一定程度上减少了木粉的极性．有效地提高复合体系的界面粘接强度,并起到了一定的增塑作用,处理木粉后所制备的复合材料力学性能下降最少。     

环氧树脂/碳纤维/BN导热复合材料制备及研究

采用高温模压成型法制备环氧树脂/碳纤/BN导热复合材料.探讨了BN用量对复合材料导热性能和力学性能的影响.结果表明,当BN用量为6%(wt)时,复合材料的弯曲强度和剪切强度较佳,BN用量对复合材料的冲击强度影响不大;导热性能随BN用量的增加而增加,当BN用量为20%(wt)时,导热系数为0.8438W/m·K.     

微米Al_2O_3层间增韧EP/CF复合材料性能研究

采用喷雾技术,通过VARTM工艺制备了微米Al2O3层间增韧环氧树脂/碳纤维复合材料,研究了微米Al2O3面密度对改性复合材料II型层间断裂韧性的影响,并进一步分析了改性对复合材料弯曲、冲击等性能的影响。研究结果表明,微米Al2O3的加入明显改善了复合材料的II型层间断裂韧性,当面密度为15 g/m2时,改性效果最好,II型层间断裂韧性由348 J/m2增加至522 J/m2,其增韧机理与裂纹的偏移、大量微裂纹的形成、Al2O3粒子从基体中拔出及与基体脱粘等现象有关。此外,改性复合材料的冲击性能得到了较好的改善,弯曲性能则稍有提高。     

Effects of Microwave Processing on Fiber-Matrix Adhesion. II. Enhanced Chemical Bonding of Epoxy to Carbon Fibers

The effect of microwave processing on the chemical interactions occurring between the carbon fiber surface and the epoxy matrix constituents was investigated using X-ray Photoelectron Spectroscopy (XPS). Monofunctional model compounds selected to duplicate the matrix constituents were exposed to the carbon fibers at temperatures similar to those encountered during composite processing. After solvent extraction, chemisorbed species were quantified by XPS. Differences were apparent in the C 1s and O 1s core electron regions of the microwave treated samples when referenced to the same elemental regions of thermally (convection) treated samples. Specifically, the atomic percentage of oxygen (in the form of carbon oxides) was increased to a greater degree when using the microwave treatment as opposed to the thermal treatments. The microwave treatment resulted in a substantial increase in the amount of chemical interaction between the fiber surface and the epoxy resin and amine components of the matrix. An epoxy resin/amine hardener adduct compound was also used to investigate the possible interaction of the adduct hydroxyl group with the carbon fiber surface. XPS results indicate a low to insignificant interaction of the hydroxyl with the carbon fiber surface under the conditions used in this study.     

Effects of Microwave Processing on Fiber-Matrix Adhesion. II. Enhanced Chemical Bonding of Epoxy to Carbon Fibers

The effect of microwave processing on the chemical interactions occurring between the carbon fiber surface and the epoxy matrix constituents was investigated using X-ray Photoelectron Spectroscopy (XPS). Monofunctional model compounds selected to duplicate the matrix constituents were exposed to the carbon fibers at temperatures similar to those encountered during composite processing. After solvent extraction, chemisorbed species were quantified by XPS. Differences were apparent in the C 1s and O 1s core electron regions of the microwave treated samples when referenced to the same elemental regions of thermally (convection) treated samples. Specifically, the atomic percentage of oxygen (in the form of carbon oxides) was increased to a greater degree when using the microwave treatment as opposed to the thermal treatments. The microwave treatment resulted in a substantial increase in the amount of chemical interaction between the fiber surface and the epoxy resin and amine components of the matrix. An epoxy resin/amine hardener adduct compound was also used to investigate the possible interaction of the adduct hydroxyl group with the carbon fiber surface. XPS results indicate a low to insignificant interaction of the hydroxyl with the carbon fiber surface under the conditions used in this study.