一种基于动态双硫键的自修复聚氨酯弹性体的制备与性能

Preparation and Properties of a Self-healing Polyurethane Elastomer Based on Dynamic Disulfide Bond

以聚丙二醇(PPG)、异佛尔酮二异氰酸酯(IPDI)和含硫扩链剂胱氨酸二甲酯(CDE)为原料,固定摩尔比为1∶3∶2,采用预聚体法制备含硫自修复聚氨酯弹性体(SPU),对SPU进行红外光谱测试、拉曼光谱测试、力学性能和自修复性能测试、划痕修复观察和DSC测试。结果表明,SPU为非晶结构,微相分离程度低;切割50%深度后,通过拉伸强度测试得出其在60℃的自修复效率达到89.8%,原因是动态双硫键的交换反应和分子链的高运动能力(硬段玻璃化转变温度<60℃)。

Using polypropylene glycol(PPG)as the soft segments,isophorone diisocyanate(IPDI)and sulfur-containing chain extender cystine dimethyl ester(CDE)as the hard segments,disulfide-containing self-healing polyurethane(SPU)was prepared through two-step process according to molar ratio of 1∶3∶2.The tests of SPU such as infrared test,Raman test,mechanical and self-healing properties test,scratch repair observation and DSC test were conducted.The results showed that SPU was amorphous structure with low degree of microphase separation.SPU had an excellent self-healing performance.When the film was cut at 50%depth,the self-healing efficiency reached to 89.8%at 60℃by tensile strength test.The good self-healing properties of SPU were resulted from the exchange reaction of dynamic disulfide bonds and the high mobility of molecular chains(Glass transition temperature of hard segment<60℃).