基于D-A反应的光固化自修复聚氨酯涂料及其性能研究

Preparation and Properties of UV-cured Self-healing Polyurethane Coatings Based on Diels-Alder Reaction

以对苯基亚甲基双马来酰亚胺(BMI)和糠醇(FA)为反应单体,通过Diels-Alder反应制备得到带羟基的改性DA单体,再以不同分子量的聚碳酸酯二元醇(PCDL)、异佛尔酮异氰酸酯(IPDI)、改性DA单体为反应单体,得到聚氨酯预聚物,然后与甲基丙烯酸羟乙酯(HEMA)反应得到光固化自修复聚氨酯。利用傅立叶红外光谱(FT-IR)、核磁共振氢谱(1 HNMR)等表征了树脂的结构,同时考察了树脂的光固化性能。再以聚氨酯树脂为基体树脂,通过配方设计制备了光固化自修复凃料。通过超景深显微镜和热重分析仪(TGA)对涂料的基本性能、自修复性能、热性能进行了测试,结果表明:随着PCDL分子量的增加,涂层的硬度有所下降,而DA单体的引入赋予涂层自修复性能的同时可以提高涂料的硬度。

N,N′-4,4′-Diphenylmethane-bismaleimide(BMI)and furfuryl alcohol(FA)were used to synthesize the modified DA monomers with hydroxyl groups through Diels-Alder reaction,and then use the polycarbonates diols(PCDL)with different molecular weights,isophorone isocyanate(IPDI)and modified DA monomers as reaction monomers to obtain a polyurethane prepolymer.Then the UV cured self-healing polyurethane were prepared by reaction of the prepolymer and hydroxyethyl methacrylate(HEMA).Fourier transform infrared(FT-IR)and nuclear magnetic resonance(1HNMR)spectra were used to characterize the structure and double bond conversion of the self-healing polyurethane.In addition,the UV cured self-healing polyurethane coatings were prepared by designing a series of coating formulations with the polyurethane.The self-healing properties and thermal properties of the coatings were tested by ultra-deep-depth microscope and thermal gravimetric analyzer(TGA).The results showed that the hardness of the coatings decreased as the molecular weight of PCDL increased,and the introduction of the DA monomer imparts self-healing properties to the coating while increasing the hardness of the coating.