外给电子体对聚丙烯结晶性能的影响

The effect of external donors on crystallization properties of polypropylene

利用3种不同的硅氧烷外给电子体制备了3种具有不同等规度和相对分子质量的聚丙烯,考察了外给电子体对聚丙烯结晶性能的影响。采用偏光显微镜和DSC对3种聚丙烯进行了等温结晶测试。实验结果表明,随外给电子体烷基位阻的增加,制备的聚丙烯的等规度增加,聚丙烯的相对分子质量也逐渐增加,结晶速率提高;随结晶温度的升高,聚丙烯的结晶速率降低。

Three kinds of polypropylenes（PPs） with different isotacticity and relative molecular mass were prepared by using three kinds of alkylsiloxane external donors. The effects of external donors on crystallization properties of PPs were introduced. The isothermal crystallization of the three kinds of PPs was tested by DSC and POM. The results showed that the isotacticity and relative molecular mass of PPs increased with the volume of alkylsiloxane as external donors. As increasing the crystallization temperature,the crystallization rate of PPs decreased.