【作者】 黄海江；

【导师】 张军营；

【作者基本信息】 北京化工大学 ， 高分子化学与物理， 2004， 硕士

【摘要】 环氧树脂因其具有良好的综合性能和工艺性而在复合材料、胶粘剂和涂料行业中有着不可替代的作用。随着高新技术的不断发展,对环氧树脂提出了越来越高的要求,因而也就不断推动着高性能环氧树脂的研究开发。本论文立足于合成一种新型的含有双键的高性能环氧树脂——二烯丙基双酚A型环氧树脂(DADGEBA), 并对该环氧树脂的基本性能及双键与环氧基团双固化的特性进行了研究。本论文采用两步法合成出了DADGEBA,并采用NMR、FTIR、DSC以及环氧值、粘度、剪切强度和浇铸体力学性能的测试对该环氧树脂的基本性能进行了研究。同时创新性的发现并采用硫磺作为该环氧树脂的固化剂,并对该体系的双固化特性、固化机理及硫磺与其它固化剂的复配效果进行了深入的研究。结果表明该环氧树脂的环氧值为0.436,其在室温下具有较低的粘度;IR谱图表明该型环氧树脂既具有环氧基团又具有烯丙基双键,是一种多官能的环氧树脂;DSC表征说明DADGEBA树脂的分子结构中虽然引入了双键,但对树脂的室温稳定性及贮存期影响较小;力学性能测试的结果表明其固化物与通用型环氧树脂E-51相比,具有较高<WP=4>的韧性及弯曲强度。对于硫磺/DADGEBA体系,通过硫磺的加入可使环氧树脂DADGEBA中的环氧基团及双键发生双固化,其固化机理为首先硫磺在高温下,八元环会发生均裂从而产生大量的链自由基,一方面硫磺自由基与烯丙基双键作用进行自由基加成反应;另一方面烯丙基中α位的活泼氢向硫磺链自由基发生转移,从而产生巯基,然后巯基与环氧基团发生开环反应;最终通过上述两种反应使整个体系交联固化。因此,通过硫磺与其它固化剂的复配,使之进行双固化反应,从而可以达到提高交联密度,改善固化物耐热性及加快固化反应的目的,为该种环氧树脂的进一步应用奠定了理论基础。更多还原

【Abstract】 As we known that epoxy resins were widely used as adhesives and matrix resin in composites. With the constant development of high technology, higher and higher request is put forward to the epoxy resin. So the enormous efforts have been made to study epoxy resins. This thesis bases on synthesizing a novel high performance epoxy resin (DADGEBA) containing double bonding and deeply study on the basic performance and double-curing behavior of epoxy DADGEBA. This thesis adopted the way of two steps to synthesize epoxy DADGEBA and deeply studied on the basic performance of epoxy DADGEBA by measuring NMR, FTIR, DSC, epoxy value, viscosity, shear strength and mechanics performance. And innovatively adopting sulfur as the curing agent of epoxy and deeply studying on the double-curing behavior, curing mechanism and the cooperating effect of sulfur and other curing agent.Results show that the epoxy value of DADGEBA is 0.436 and it has relatively lower viscosity in room temperature. IR spectra indicate the <WP=6>epoxy DADGEBA has double bonding in the molecular and it is a kind of multifunctional epoxy. DSC curves indicate that the epoxy resin has relatively longer pot time in room temperature though there has double bonding in the molecular. Mechanics performances show that epoxy DADGEBA has higher toughening and bending strength. For system S/DADGEBA, epoxy DADGEBA may carry out double curing. The curing reactions were likely contributed to two ways. A sulfur-sulfur bond was firstly broken to form two sulfur radicals when heated to relatively high temperature, and then a sulfur radical would captured a α-H atom in ally group to form a mercapto(SH) group and the ally group to form a carbon radical. The radicals (carbon or sulfur) resulted in radical polymerization reaction of double bond in the allyl group or the coupling reaction between two radicals. In the other hand, the epoxy group in DADGEBA was easily opened with the mercapto(SH) group to form C-S bond . Finally the system is cured by above two kinds of reactions. So by the cooperating effect of sulfur and other curing agent, the systems may carry out double curing and consequently it can enhance the cross-linking density, improve the thermal resistance and quicken the curing reactions and lay a stability foundation on the deep theory research.更多还原