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通过对比研究硫磺固化液体丁腈橡胶、液体丁腈橡胶/苯基缩水甘油醚、液体丁腈橡胶/邻烯丙基苯基缩水甘油醚3个体系的固化反应,推测了硫磺/含双键橡胶/环氧树脂体系的反应机理.采用示差扫描量热(DSC)法、红外光谱(FTIR)法、X射线光电子能谱(XPS)法、动态力学分析(DMA)法研究了固化反应放热,双键和环氧基团随反应时间的变化,固化产物中苯环、氧元素、网络结构与模型化合物结构的关系.实验结果表明,硫磺/液体丁腈橡胶体系是一步反应、硫磺/液体丁腈橡胶/环氧化合物体系是两步反应,且丁腈橡胶与环氧化合物之间有化学键键接;液体丁腈橡胶/硫磺、液体丁腈橡胶/苯基缩水甘油醚/硫磺、液体丁腈橡胶/邻烯丙基苯基缩水甘油醚/硫磺3个体系的玻璃化转变温度依次升高,储能模量、交联密度依次降低.在此基础上提出液体橡胶与环氧化合物的固化反应机理为:硫磺裂解生成硫自由基,一方面部分硫自由基与体系中的双键发生加成反应,另一方面硫自由基与烯丙基α位的活泼氢反应生成巯基,巯基引发环氧基团发生开环反应,体系内的自由基间相互偶合交联.
By comparing the curing reaction of the three systems of nitrile rubber, liquid nitrile rubber / phenyl glycidyl ether, liquid nitrile rubber / o-allyl phenyl glycidyl ether, the sulfur / double bond rubber / Epoxy resin system.The reaction heat of curing reaction was studied by differential scanning calorimetry (DSC), infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and dynamic mechanical analysis (DMA) The relationship between the benzene ring, oxygen element, network structure and the structure of the model compound in the cured product of double bonds and epoxy groups changes with the reaction time.The experimental results show that the sulfur / liquid nitrile rubber system is a one- Nitrile rubber / epoxy system is a two-step reaction, and nitrile rubber and epoxy compounds have a chemical bond between; liquid nitrile rubber / sulfur, liquid nitrile rubber / phenyl glycidyl ether / sulfur, liquid nitrile The glass transition temperature of rubber / o-allyl phenyl glycidyl ether / sulfur increased in turn and the storage modulus and crosslinking density decreased in turn. On this basis, the curing reaction of liquid rubber and epoxy compound Mechanism is : Sulfur pyrolysis generated sulfur free radicals, on the one hand part of the sulfur free radicals and system double bond addition reaction, on the other sulfur free radicals and allylic active hydrogen α position generated mercapto, mercapto group initiated epoxy group Ring-opening reaction occurred, the system of coupling between the coupling of free radicals.