基于热可逆Diels-Alder动态共价键PU-DA体系的制备和性能

Preparation and Properties of PU-DA System Based on Thermoreversible Diels-Alder Dynamic Covalent Bond

使高度柔性的聚四氢呋喃二醇(PTMG)基材与糠基缩水甘油醚-2-呋喃甲胺(FGE-FA)反应得到四元呋喃结构的聚氨酯预聚物,再将其与含亲双烯体结构的双马来酰亚胺反应制备出高密度Diels-Alder(DA)动态共价键结构的自修复聚氨酯(PU-DA)。用FTIR、DSC和OM表征PU-DA的结构,用电子万能试验机测试了PU-DA的性能。结果表明:在PU-DA中引入了DA动态共价键后,其正、逆反应温度分别为70℃和132℃;PU-DA具有良好的重塑性、溶胀溶解性和多次自修复性能。受损试样在70℃修复4 h裂纹即基本愈合,第一次修复率可达94.8%,三次修复率仍高于70%。

The highly flexible polytetrahydrofuranediol(PTMG)substrate was reacted with furfuryl glycidyl ether-2-furanethylamine(FGE-FA)to obtain the polyurethane prepolymer of tetrahydrofuran structure,and then it was reacted with bismaleimide of dienophile structure to prepare high density Diels-Alder(DA)self-healing polyurethane(PU-DA)with dynamic covalent bond.The PU-DA was characterized by FTIR,DSC and OM,and the performance of PU-DA was tested by electronic universal testing machine.The results show that the forward and reverse reaction temperatures of PU-DA are 70℃and 132℃,respectively,after the introduction of DA dynamic covalent bond.PU-DA has good performance in remodeling,swelling solubility and multiple self-healing.Cracks of the damaged PU-DA could basically be healed by heating at 70℃for 4 h,meanwhile,the first repair rate could 94.8%,and the third repair rate was still higher than 70%.