摘要
为了获得较高的环氧树脂韧性,本文合成了嵌段异氰酸酯的预聚物和具有特殊结构的环氧树脂强韧固化剂。首先,通过甲苯二异氰酸酯(TDI)和扩链剂的扩链反应制备异氰酸酯末端预聚物,然后与咪唑(MI)进一步合成封端的异氰酸酯预聚物,该咪唑通常用作封端剂。用低聚物作为增韧剂对环氧树脂进行改性,然后在指定温度下固化。在实验中,研究了不同剂量的不同封闭剂,反应温度,时间和不同的进料方式对封闭率的影响,以及不同介质对封闭温度的影响。结果表明,合成封闭的多异氰酸酯的最佳条件为:MI/-NCO的摩尔比为1.1-1.2,封闭反应温度为60℃,封闭反应时间为3h;固化时间温度为100℃,时间为3h。
In order to obtain high toughness of epoxy resin,in this paper,prepolymer of blocked isocyanate and tough curing agaent with special structure for epoxy resin is synthesized.First,isocyanate terminal prepolymer are prepared through chain extension reaction of toluene diisocyanate(TDI)and chain extender,and then blocked isocyanate prepolymer is further synthesized with imidazole(MI)which is often used as the blocking agaent.The epoxy resin is modified using the oligomer as a toughening agent,then cure at the specified temperature.In the experiment,the effects of different dosages of different blocking agents,reaction temperatures,time and different feeding methods on the blocking rate are studied,also the effects of different media on the deblocking temperature.The results show that the optimum conditions for the synthesis of blocked poly-isocyanates are found as follows:the molar ratio of MI/-NCO is from 1.1 to 1.2,the blocking reaction temperature is 60℃,and the blocking reaction time is 3 h;curing time temperature is 100℃,time is 3 h.
作者
王哲彭
程瑶
张宇鹏
田雨
Wang Zhepeng;Cheng Yao;Zhang Yupeng;Tian Yu(School of Chemical Engineering,Northwest Minzu University,Gansu,730124)
出处
《当代化工研究》
2020年第23期34-35,共2页
Modern Chemical Research
关键词
异氰酸酯
封闭剂
扩链剂
环氧树脂
isocyanate
blocking agaent
chain extender
epoxy resin
