氨酯脲型聚醚胺的合成及其增韧环氧树脂的研究

合成了不同相对分子质量的四元伯胺封端的氨酯脲型聚醚胺（TAPEU），并用于增韧双酚A型环氧树脂/二乙烯三胺（DGEBA/DETA）固化体系。利用核磁氢谱和傅里叶红外光谱（FT IR）表征了TAPEU的结构，系统表征了TAPEU改性DGEBA/DETA材料的氢键化程度、玻璃化转变温度、交联网络结构、拉伸断裂面形貌特征以及材料的力学性能。结果表明，成功合成了不同相对分子质量的TAPEU；当TAPEU相对分子质量增加时，材料交联密度降低，氢键化作用增强，玻璃化转变温度有所增加；引入TAPEU改性环氧树脂材料体系，断裂面具有明显韧性断裂特征，且出现微相分离；TAPEU改性环氧树脂材料的韧性和冲击强度有明显的提高。与未改性环氧树脂相比，添加摩尔分数为50% TAPEU2000的改性材料冲击强度提高了65%，断裂伸长率提高了330%。

Synthesis of Tetra Amine Terminated Polyether with Urethane Urea Groups and Its Application for Toughening Agent in Epoxy Resin

Different molecular weights of tetra amine terminated polyether with urethane urea groups (TAPEU) were synthesized and characterized with FT IR and NMR. Then, TAPEUs were used as toughening agent for diglycidyl ether of bisphenol A epoxy resin (DGEBA)/diethylenetriamine (DETA) system. The degree of hydrogen bonding, glass transition temperature, network structure, tensile fracture morphology and mechanical properties of the modified epoxy resins were investigated. The results showed that with the increasing molecular weight of TAPEU in the toughened epoxy systems, the crosslinking density decreased, the degree of hydrogen bonding enhanced, and the glass transition temperature increased. Tensile fracture morphology became rough, the micro phase structure was observed, and toughness and impact resistance improved significantly when TAPEU was introduced into the epoxy resin. Compared with neat epoxy, the impact strength and elongation at break of the TAPEU2000 50 modified epoxy resin was enhanced by 65% and 330%, respectively.