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合成了含不同分子量柔性间隔基的扩链脲（Ｕｉ），并对其与双氰双胺共同固化环氧树脂体系的反应活性、抗冲击性能、动态力学性能、形态结构及贮存性能进行了考察。结果表明：含分子量为４００的聚乙二醇柔性链的扩链脲／双氰双胺／环氧树脂固化体系的抗冲击强度较单纯双氰双胺／环氧树脂固化体系提高了７倍左右，其冲击试样断面电镜照片呈韧性断裂的特征。扩链脲的反应活性基本不受分子中聚乙二醇链段分子量的影响。环氧树脂／扩链脲／双氰双胺体系在５０℃下贮存期可达１～２天。
Synthesis of extended-chain ureas (Ui) containing flexible spacers of different molecular weights and their reaction activity, impact resistance, dynamic mechanical properties, morphological structure and storage properties with dicyandiamide were investigated . The results show that the impact strength of the chain extended with urea / dicyandiamide / epoxy resin with a molecular weight of 400 is more than that of the pure dicyandiamide / epoxy resin system , The impact specimen cross-section electron micrographs showed the characteristics of ductile fracture. The activity of the extended-chain urea is basically not affected by the molecular weight of the polyethylene glycol segment in the molecule. Epoxy resin / extended chain urea / dicyandiamide system at 50 ℃ storage period of up to 1 to 2 days.