固化(化学)
环氧树脂
热固性聚合物
聚氨酯
缩水甘油醚
材料科学
极限抗拉强度
芳香胺
复合材料
复合数
双酚A
胺气处理
自催化
高分子化学
化学
有机化学
催化作用
作者
Nikita A. Bratasyuk,V. V. Zuev
标识
DOI:10.1016/j.tca.2020.178598
摘要
The cure kinetics of thermosetting polyurethane/epoxy composites based on oligomeric diglycidyl ether of bisphenol A and branched oligomeric diphenylmetane diisocyanate and polymeric aliphatic amine or mixture of low molecular weight aromatic amines as hardener was studied. It was shown that curing process comprises three stages: at first, a polyurethane network is formed, after that amine hardener react with epoxy oxirane rings with formation linear oligomers, and at the final stage of curing, the network is formed by reaction of secondary amines obtained on the second stage with epoxy oxirane rings. The isoconversional methods of Flynn–Wall–Ozawa and Kissinger-Akahira-Sunose were employed to investigate activation energy as a function of curing degree. The correlation between Ea and α determined by these methods indicated that there were autocatalytic effects in curing systems under study. Interestingly, the mixture of low molecular weight aromatic amines curing compositions exhibited the highest tensile strength and elongation among all materials studied. It means that slow curing with separated stage of composite formation leads to composite with more regular structure which improved their mechanical performance.
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