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采用分子动力学模拟方法构建了环氧树脂/SiO2界面模型,研究了呋喃环氧树脂和胺类固化剂分子随着交联反应的进行在界面层局部浓度的变化以及界面层形成的动力学因素。研究结果表明:沿着远离SiO2表面的方向,树脂及其固化物的浓度呈现先增加、达到峰值、然后逐渐减小、最后趋于平稳的变化趋势;交联反应未发生时,固化剂分子与SiO2表面之间具有较强的界面相互作用能,所以在界面层内胺基氢浓度高于环氧基团浓度;随着固化反应转化率的提高,环氧树脂交联网络逐渐形成,进一步限制了胺基氢和环氧基团的运动能力,未反应的胺基氢和环氧基团不均匀分布被限定;当交联反应程度达到85%时,界面层内残余的胺基氢浓度仍高于环氧基团浓度。而且,胺基在界面层的这种富集现象造成了界面层的交联密度低于树脂层的交联密度。
Abstract：A model of epoxy resin/SiO2 interface was constructed by molecular dynamics simulation method.The local concentration changes in the interface layer of furan epoxy resin and amine curing agent with the process of crosslinking reaction and the dynamic factors of interface layer formation were studied. The research results showed that the concentration of resin and its cured products increased first,reached the peak,then gradually decreased,and finally tended to be stable along the direction away from the surface of SiO2. When the crosslinking reaction did not occur,there was strong interface interaction energy between the curing agent molecule and SiO2 surface,so the concentration of amine hydrogen in the interface layer was higher than that of epoxy groups.With the increase of conversion rate of curing reaction,the crosslinking network of epoxy resin was gradually formed,which further restricted the movement ability of amine hydrogen and epoxy resin,and the uneven distribution of unreacted amine and epoxy groups was limited. The concentration of residual amine hydrogen in the interface layer was still higher than that of epoxy groups when the crosslinking reaction degree reached 85%.Moreover,the enrichment of amine groups in the interface layer resulted in the crosslinking density of the interface layer to be lower than that of the resin layer.
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基本信息:
DOI：10.13416/j.ca.2022.02.010
中图分类号:TQ323.5;TB332
引用信息:
[1]李婉莹,谢星宇,任晏等.呋喃环氧树脂/SiO_2界面层特性的分子动力学模拟[J].中国胶粘剂,2022,31(02):1-9.DOI:10.13416/j.ca.2022.02.010.
基金信息: