端异氰酸酯基聚醚接枝环氧树脂的性能研究

合成了端异氰酸酯基聚醚（ITPs）改性双酚A型环氧树脂，通过红外光谱（IR）、动态热机械分析（DMA）研究了ITPs和EP之间的化学反应及改性环氧树脂酸酐固化体系的热性能，并测试了固化体系的力学性能。结果表明：ITPs作为枝链接枝到环氧树脂上：随着加入ITPs质量分率增加，其固化体系的冲击强度和弯曲强度上升，当ITPs含量为10％时，两者达到最大值：动态热机械分析（DMA）结果表明改性环氧树脂固化体系的玻璃化转变温度（Tg）随ITPs的含量增大而降低：当ITPs质量分率大于15%时，过量的ITPs与改性环氧树脂会形成相分离。     

含缺陷钢管复合材料修补抗内压疲劳性能研究

制备出带有壁厚减薄缺陷的钢管,研究了玻璃纤维复合材料环向补强对钢管抗内压性能的影响。结果表明,缺陷面积决定复合材料的补强面积,复合材料补强边界宽度超过缺陷轴向长度的80%时,补强效果较好,爆破时复合材料断裂,可充分发挥其性能;通过合理的设计,补强钢管的短时爆破压力大于30MPa,达到无缺陷钢筒爆破压力水平,同时疲劳次数大于15000次,补强效果优异。     

热塑性复合材料制备工艺概述

本文介绍了热塑性复合材料的发展现状。综述了热塑性复合材料的主要制备技术和成型工艺方法。     

支链化环氧树脂固化反应动力学研究

采用差示扫描量热法(DSC)测量了端羟基聚醚改性环氧树脂的固化过程,研究了不同配比对固化反应的影响,得出了固化反应过程的动力学参数,确定了支链化环氧树脂的固化工艺。结果表明:以甲基四氢苯酐为固化剂的体系中,不同分子量的端羟基聚醚改性环氧树脂的固化反应,其反应级数相同,但反应的活化能随分子链的增长略有降低。     

活性稀释剂种类对环氧树脂体系性能的影响研究

采用丁基缩水甘油醚(660)、乙二醇二缩水甘油醚(669)和苯基缩水甘油醚(690)三种活性稀释剂对环氧树脂/甲基四氢邻苯二甲酸酐(MeTHPA)固化体系进行改性,研究了稀释剂对树脂胶液粘度及其固化物力学性能和电性能的影响。结果表明,当加入669和690稀释剂后,体系的介电性能基本不变,耐电弧性能提高,而660的加入会降低体系的介质损耗,对耐电弧性能影响很小。其中,当690的添加量为3%时,耐电弧达到94s,比纯树脂提高了22%;当添加量为3%～12%时,树脂固化物的拉伸强度稳定在45～55MPa之间。     

不同铺层复合材料螺栓连接的研究

实验研究了在E/D=4(边距/孔径),W/D=5(宽度/孔径)的3种铺层[90/+45/-45/0]s,[90/0/+45/-45]s,[+45/-45/90/0]s的玻璃纤维/环氧复合材料试样在不同的扭矩和垫片尺寸(外径(Dw)/内径(D))下的静态破坏强度。实验结果表明,试样破坏强度随夹持力增大而增大,但增加趋势不断减弱,在5Nm扭矩下三种铺层的强度分别比其销钉连接增大175%,196%,141%;在销钉连接下,[90/+45/-45/0]s铺层强度比[90/0/+45/-45]s铺层高12.7%,[+45/-45/90/0]s铺层强度比[90/+45/-45/0]s铺层高10.8%;在手动拧紧下[90/+45/-45/0]s铺层强度比[90/0/+45/-45]s铺层高3.5%,而[+45/-45/90/0]s铺层强度比[90/+45/-45/0]s铺层高0.37%;垫圈的外内径比在2～3范围内,试样强度伴随外内径比的增大而增大,在3～4时,强度变化很小。     

Isocyanate-terminated Polyethers Toughened Epoxy Resin:Chemical Modification,Thermal Properties,and Mechanical Strength

The toughening of the diglycidyl ether of bisphenol A epoxy resin with isocyanate-terminated polyethers(ITPE)was investigated.The progress of the reaction and the structural changes during modification process were studied using FTIR spectroscopy.The studies support the proposition that TDI(tolylene diisocyanate)acts as a coupling agent between the epoxy and polyethers,forming a urethane linkage with the former and the latter,respectively.Me THPA-cured ER/ITPs blends were characterized using dynamic mechanical analysis(DMA)and thermogravimetric analysis(TGA).It is indicated the glass transition temperature(T g )of systems was lower than the T g of pure epoxy resin and overfull ITPE separated from the modified epoxy resin and formed another phase at an ITPE-content of more than 10wt%.The thermal stability was decreased by the introduction of ITPE.The impact strength and the flexural strength of the cured modified-epoxy increased with increasing the ITPE content and a maximum plateau value of about 24.03 kJ/m2 and 130.56 MPa was measured in 10wt%ITPE.From scanning electron microscopy(SEM)studies of the fractrue surfaces of ER/ITPE systems,the nature of the micromechanisms responsible for the increases in toughness of the systems was identified.     

Isocyanate-terminatcd Polyethers Toughened Epoxy Resin： Chemical Modification, Thermal Properties, and Mechanical Strength

The toughening of the diglycidyl ether of bisphenol A epoxy resin with isocyanateterminated polyethers （ITPE） was investigated. The progress of the reaction and the structural changes during modification process were studied using FTIR spectroscopy. The studies support the proposition that TDI （tolylene diisocyanate） acts as a coupling agent between the epoxy and polyethers, forming a urethane linkage with the former and the latter, respectively. Me THPA-cured ER/ITPs blends were characterized using dynamic mechanical analysis （DMA） and thermogravimetric analysis （TGA）. It is indicated the glass transition temperature （T） of systems was lower than the T of pure epoxy resin and overfull ITPE separated from the modified epoxy resin and formed another phase at an ITPE-content of more than 10wt%. The thermal stability was decreased by the introduction of ITPE. The impact strength and the flexural strength of the cured modifiedepoxy increased with increasing the ITPE content and a maximum plateau value of about 24.03 kJ/m^2 and 130.56 MPa was measured in 10wt% ITPE. From scanning electron microscopy （SEM） studies of the fractrue surfaces of ER/ITPE systems, the nature of the micromechanisms responsible for the increases in toughness of the systems was identified.     

碳纤维复合材料缠绕制品抗外压性能研究

研究了树脂基体模量、缠绕角和厚度对碳纤维复合材料缠绕制品抗外压性能的影响。实验结果表明:采用MNA共混PMDA固化环氧树脂并调整PMDA含量可以有效改变树脂模量,随着PMDA含量的增加,树脂模量提高。当PMDA含量仅为MNA的5%时,树脂模量从3.71 GPa增加到4.18 GPa,提高了13%;当PMDA含量为MNA的10%时,模量达到最大值,为4.61 GPa,提高了24%。随着基体模量增加,单向CFRP的压缩强度、剪切强度和环刚度均先增加后减少。当基体模量为4.18GPa时,CFRP的压缩强度和剪切强度均达到最大值,分别为655 MPa和71.6 MPa,提高了16%和12%。此时,缠绕管环刚度达到最大值,为277 k N/m~2,提高了87%;同时增加缠绕角和厚度能够提高缠绕管的抗失稳能力。     

玻璃纤维毡增强聚丙烯材料弯曲性能的研究

研究了玻璃纤维含量、偶联剂处理、乳液处理等几种因素对复合材料弯曲性能的影响。实验发现玻璃纤维毡增强聚丙烯片材的弯曲强度随着玻璃纤维含量的改变而变化。当玻璃纤维含量为 33%左右时 ,弯曲强度达到最大98.82 MPa。用 EVA乳液或硅烷偶联剂处理玻璃纤维后 ,按相同工艺压制的复合材料的弯曲强度不同程度地得到了提高。当 EVA乳液为某一浓度时 ,弯曲强度最大提高了约 2 0 % ,达到了 117.0 5 MPa;而用硅烷偶联剂处理玻璃纤维表面 ,弯曲强度提高的幅度较小