聚醚型聚氨酯/超支化聚酯互穿聚合物网络的形态和力学性能

Morphology and Mechanical Properties of Polyurethane/Hyperbranched Polyester IPN

为了改善聚醚型聚氨酯弹性体(PU)的力学性能,运用互穿聚合物网络(IPN)技术,分别将端正己烷基、端十二烷基、端十八烷基超支化聚酯(HBP-C6、HBP-C12、HBP-C18)引入至PU中形成共混体系。结果表明,相比于空白胶片,PU/HBP IPN体系的力学性能有了一定的提高,超支化聚酯端烷烃链越长,相畴尺寸逐渐减小,互穿程度更高;高含量的HBP-C18加入后,随着其质量分数的增加,互穿网络胶片的拉伸强度和断裂伸长率均呈现出先增大后减小的趋势,加入30%的HBP-C18时,形成了双相连续的微观结构;采用"准一步法"和"一步法"合成端十八烷基超支化聚酯,分别与聚氨酯形成互穿网络,力学测试结果表明,前者的力学性能优于后者。

In order to improve mechanical properties of polyether polyurethane elastomer( PU),three kinds of alkylterminated hyperbranched polyesters( HBP-C6,HBP-C12,HBP-C18) were introduced by interpenetrating polymer network( IPN) modification technique. The results show that mechanical properties of IPN are improved when the content of HBP is low. The longer the end-chain alkanes of hyperbranched polyesters is,the smaller the phase domain size becomes. When the content of HBP-C18 is high,both the tensile strength and the elongation at break of IPN increase first and then decrease. When the content of HBP-C18 is 30%,the dual continuous interpenetrating networks are observed in IPN. The tensile strength is 1. 76 times than that of PU,and the elongation at break is as high as 2055%,7. 56 times higher than before. The effect of synthetic method of HBP-C18 such as pseudo one-step method and one-step method on mechanical properties of IPN was also studied. The results show that the former performs better mechanical properties.