自乳化水性环氧树脂的制备

采用聚醚醇二缩水甘油醚(PEGGE)、乙醇胺(MEA)及冰乙酸对双酚A环氧树脂(DGEBA)化学改性,在不需Lewis酸催化剂条件下制备低污染、高性能水性环氧树脂。首先,在物料摩尔比(MEA/PEGGE)2∶1,反应温度55℃,反应时间4h下,用PEGGE对MEA扩链合成MEA-PEGGE加成物;然后,在物料摩尔比(DGEBA/MEA-PEGGE)2∶1,反应温度65℃,反应时间5h下,用MEA-PEGGE加成物对DGEBA扩链,合成DGEBA-MEA-PEGGE加成物;再采用冰乙酸与DGE-BA-MEA-PEGGE加成物成盐,制备出具有良好水溶解分散性能的自乳化水性环氧树脂。该树脂涂膜性能优良,具有良好柔韧性和耐冲击性,改善了普通环氧树脂性能较脆的缺陷。

Preparation of Self-Emulsified Waterborne Epoxy Resin

A drawback of epoxy resins is their inherent brittleness. It is a trend to develop high performance epoxy resin with low pollution. The novel self-emulsified waterborne epoxy resin was synthesized without corrosive Lewis acid as catalyst: Firstly,in order to incorporate the hydrophilic and soft polyglycol segment,diglycidyl ether of polyglycol (PEGGE) as chain extender reacted with monoethanolamine (MEA) in propylene glycol methyl ether (PM) to synthesis MEA-PEGGE adduct. Secondly,MEA-PEGGE adduct as chain extender reacted with diglycidyl ether of bisphenol-A(DGEBA) to synthesis DGEBA-MEA-PEGGE adduct. In order to improve the water solubility of DGEBA-MEA-PEGGE adduct,acetic acid was used. And the influences of salting degree on the water solubility of DGEBA-MEA-PEGGE adduct were discussed. Finally,after PM was removed by distillation,water was added to the DGEBA-MEA-PEGGE adduct at 50 ℃～60 ℃ until solids content becomes 50%. The two-component film of prepared waterborne epoxy resin and waterborne epoxy curing agent has good properties especially with the good flexibility and impact resistance.