含DA键的自修复交联型聚氨酯弹性体的制备与再加工

Synthesis and Reprocessing of Self-Healing Crosslinked Polyurethane Containing Diels-Alder Bonds

通过预聚法,制备了具有自修复性且可重新加工成型的新型交联聚氨酯(CPU-DA),利用傅里叶变换红外光谱仪(FT-IR),差示扫描量热仪(DSC),热台显微镜,电子万能材料试验机等对聚氨酯中的DA键的热可逆性能和该聚氨酯的热性能进行了研究。研究表明:CPU-DA具有快速自修复性和多次再加工性。在110℃下热处理10 min后,裂缝愈合且修复效率达81.6%;碾碎加热压铸再加工三次后拉伸强度不仅没有下降,反而提高了65%以上,由原样的8.56MPa增加到14.14 MPa。

A new family of crosslinked polyurethane(CPU-DA)was synthesized via prepolymer processes,which was cable of repeatedly self-healing and reprocessing.Thermal-reversible performance of DA,self-healing efficiency and thermal properties of CPU-DA were characterized by FTIR,DSC,Hot-Stage polarization microscope and electronic universal material testing machine.The results demonstrate that CPU-DA exhibits excellent quick self-healing ability and thermal reversibility.Crack can be completely healed in less than 10 minutes at 110℃,and CPU-DA shows excellent thermal-healing ability with an efficiency of 81.6%considering breaking stress.The tensile strength of CPU-DA at the break increases from 8.56 to 14.14 MPa after hot molding for three times,which is different from that usually observed in traditional polyurethanes.Meanwhile,the tensile strength of CPU-DA increases by more than 65%.