扩链脲改性环氧树脂E-51/双氰双胺(dicy)体系的固化行为  

Curing Behavior of E-51/Dicyandiamide Modified with Extended Chain Ureas

作　　者：何尚锦[1] 石可瑜[1] 张珍坤[1] 李亮[1] 杜宗杰[1] 张保龙[1] 

机构地区：[1]南开大学化学系.吸附分离功能高分子材料国家重点实验室,天津300071

出　　处：《应用化学》2001年第11期857-860,共4页Chinese Journal of Applied Chemistry

基　　金：国家自然科学基金 ( 5 94730 2 8);天津市自然科学基金资助项目 ( 9836 0 3111)

摘　　要：以聚醚 PPG1 0 0 0、甲苯二异氰酸酯 ( TDI)合成预聚体 ,然后分别以二甲胺、咪唑、2 -甲基咪唑对其封端 ,合成了 3种结构不同的活性增韧促进剂扩链脲 ( TP、TI0 、TI1 ) .利用 DSC、动态粘弹谱仪、冲击试验机和SEM对 3种扩链脲改性环氧树脂 E-5 1 /双氰双胺 ( dicy)固化体系的反应活性、玻璃化温度、冲击性能及试样断裂面的形态结构进行了系统研究 .结果表明 ,经过改性的固化体系的固化反应活性明显提高 ,固化反应峰顶温度从未改性体系的 1 90℃降至 1 2 0～ 1 4 0℃ ,表观活化能从未改性体系的 1 31 k J/mol降至 70～80 k J/mol.其中经过 TI系列扩链脲改性的环氧树脂 E-5 1 /双氰双胺固化体系的冲击强度提高至未改性体系的 2～ 3倍 ,而其玻璃化温度基本不变 .Three kinds of reactive toughening accelerators for epoxy resin/dicyandiamide system, amine terminated chain extended urea(TP), imidazole terminated chain extended urea(TI 0) and 2 methylimidazole terminated chain extended urea (TI 1) were synthesized from polyurethane prepolymer. Compared with the unmodified system, the curing activity, glass transition temperature, impact property and fracture surface morphology of the modified systems were investigated by DSC, SEM and measurement viscoelasticity. The results show that the curing activity was so greatly enhanced that the curing peak temperature decreased from 190 ℃ for the unmodified system to 120～140 ℃ for the modified systems, and the apparent activation energy of curing reaction decreased from 131 kJ/mol to 70～ 80 kJ/mol . Furthermore, the impact strength of the curing systems modified with TI n was 2～3 times as high as that of the unmodified system, while the glass transition temperature was little changed, and the fracture surface of the modified systems became tougher.

关 键 词：环氧树脂 扩链脲 反应活性 形态 结构 改性 固化反应 双氰双胺 增韧促进剂 

分 类 号：TQ323.5[化学工程—合成树脂塑料工业] TQ316.6