双酚F环硫/环氧树脂/胺体系固化反应及其交联网络的研究

合成了双酚F环氧/环硫树脂，采用元素分析、红外光谱分析和核磁共振光谱分析确定了合成树脂的结构,对比研究了环硫基团/环氧基团为0/100、15/85和50/50（质量比）的双酚F环硫/环氧树脂与脂环胺DMDC固化剂体系的固化行为。通过差示扫描量热仪（DSC）、动态力学热分析仪（DMTA）等手段研究了固化剂配比对体系固化程度、固化物的模量和玻璃化转变温度的影响，结果显示：当环硫基团质量分数从0分别增加到15%和50%时，环硫/环氧树脂/胺体系不仅固化速度加快，且固化剂用量相应减少约15%和50%，说明胺基与环硫基团开环反应形成的—SH或—S-可作为固化剂进一步与环氧基团和环硫基团进行开环反应；另一方面，固化物的模量和玻璃化转变温度有所提高，说明环硫树脂固化物交联网络更密集，也证明了环硫/环氧树脂的固化反应行为与环氧树脂存在不同。

The curing reaction and cross-linked network of the bisphenol-F thiirane/epoxy/amine system

The structure of thiirane is similar to that of epoxy resin with the oxygen atoms being replaced by sulfur atoms. Thiirane and epoxy resin have many similarities in terms of curing mechanism and performance, however, they show different curing behavior. In this work, bisphenol-F episulfide/bisphenol-F epoxy resin (BPFES/BPFER) materials with mass ratios of 0/100, 5/85 and 50/50 were successfully prepared and their structures were determined by elemental analysis, infrared spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. The dependence of the degree of curing on the content of curing agent was investigated by using differential scanning calorimetry (DSC). The dependence of the modulus and glass transition temperature on the content of curing agent was investigated by using dynamic mechanical thermal analysis (DMTA). The results showed that when the content of S-based ring groups increases from 0 to 15% and then to 50%, the curing speed of the thiirane/epoxy/amine system increases, and at the same time, the consumption of the curing agent is reduced by approximately 15% and 50%, respectively. This is because the —SH and —S- moieties can combine with the curing agent to make the thiirane and epoxy rings open and act as a curing agent. In addition, the modulus and glass transition temperature of the cured material were improved, which indicates that the cross-linked network structure of cured thiirane/epoxy resin was more compact, confirming that differences in curing behavior exist between thiirane and epoxy resin.