超支化聚氨酯改性水性环氧树脂固化剂的制备与性能

以异佛尔酮二异氰酸酯(IPDI)、二羟甲基丙酸(DMPA)和二乙醇胺(DEOA)为原料,合成出了超支化聚氨酯核HBPU-0;以IPDI、聚醚多元醇(N210)、DMPA等原料合成线型聚氨酯,然后将线型聚氨酯接枝到HBPU-0上,制备出超支化聚氨酯(HBPU);再以HBPU、环氧树脂E-44、丁基缩水甘油醚单封端的四乙烯五胺(TEPA-660a)为主要原料制备出超支化聚氨酯改性水性环氧树脂固化剂。用红外光谱、核磁共振、透射电镜、扫描电镜和热失重等方法表征和测试了聚合物的结构与性能,研究了HBPU含量对固化膜断面形貌、力学性能、热性能的影响。结果表明,当HBPU质量分数达到24%时,固化膜的综合性能最佳,此时冲击强度为23.4kJ/m2,拉伸强度为52.4 MPa,5%和50%的质量热损失温度分别为287.5℃和376℃,与未改性环氧树脂相比,柔韧性和耐热性均有显著提高。

Preparation and Properties of Waterborne Epoxy Curing Agent Modified with Hyperbranched Polyurethane

Hyperbranched polyurethane (HBPU-0) was prepared from isophorone diisocyanate (IPDI),dimethylol propionic acid(DMPA) and diethanol amine(DEOA),and linear polyurethane was prepared from IPDI,polyether polyol(N210) and DMPA.Linear polyurethane was grafted to HBPU-0,and reacted with epoxy resin (E-44) and mono-capped tetraethylene pentamine by N-butyl glycidyl ether (TEPA-660),then the waterborne curing agent modified with hyperbranched polyurethane(HBPU) was prepared.The structure and properties of polymer were characterized by IR,13C-NMR,TEM,SEM and TG;and effects of the HBPU content on the fractured surface morphology,mechanical properties and thermal properties of the cured film were studied.The results show that when the HBPU mass fraction is 24 ％,the cured film has the best comprehensive performance,the impact strength is 23.4 kJ/m2,the tensile strength is 52.4 MPa,the characteristic decomposition temperature at 5 ％ and 50 ％ mass loss is 287.5 ℃ and 376 ℃ respectively,and the flexibility and heat resistance are improved significantly compared with unmodified epoxy resin.