基于动态受阻脲键的可修复环氧树脂的制备及性能

Preparation and Properties of Self-healing Epoxy Resin Based on Dynamic Hindered Urea Bonds

以大位阻仲胺和异氰酸酯为原料,合成了基于大位阻脲键的环氧固化剂,并以4, 4’-二氨基二苯甲烷为交联剂,制得了基于大位阻脲键的热可逆结构稳定性自修复环氧热固性树脂。对合成的含大位阻脲键的环氧树脂进行了进行拉伸性能测试、热机械性能测试(DMA)、热重测试(TG)、可修复性能和可再加工性能测试。结果表明,拉伸强度达到68.62 MPa,断裂伸长率达到了6.93%,有效解决了环氧树脂的脆性难题,并且能够保持相对优异的力学性能,从而具有实际应用价值。同时,这种新型材料可以在120℃下10 min内实现快速愈合,大位阻脲键赋予了环氧热固性材料优异的再加工性、自愈合性、焊接性、可重塑性、可循环性和形状记忆性。因此,将大位阻脲键引入热固性环氧树脂,为以经济高效的方式制备具有高机械强度和自愈合效率的环氧热固性树脂提供了一种可行的策略。

An epoxy curing agent based on large hindered urea bond was synthesized using hindered diamine and isocyanate as raw materials,and a self-healing epoxy thermosetting resin with thermal reversible structure stability based on large hindered urea bond was successfully prepared by using 4,4’-diaminodiphenylmethane(DDM)as cross-linking agent.The tensile properties,dynamic mechanical analysis(DMA),thermal gravimetric analysis(TGA),self-healing properties and reprocessability of the synthesized epoxy resin with hindered urea bond were tested.The tensile strength reached 68.62 MPa,and the elongation at break reached 6.93%,effectively overcoming the brittleness issue of epoxy resins while maintaining relatively superior mechanical properties.Therefore,it has practical application value.At the same time,this new material can achieve rapid healing within 10 min at 120℃.The hindered urea bond endowed the epoxy thermosetting material with excellent reprocessability,self-healing ability,weldability,reshaping capability,recyclability,and shape memory effect.Therefore,introducing the hindered urea bond into thermosetting epoxy resin provides a feasible strategy for preparing epoxy thermosetting resin with high mechanical strength and self-healing efficiency in an economical and efficient way.