全同立构聚丙烯振动注射试样晶体结构的变化

Change of Crystal Structures of Isotactic Polypropylene Samples Prepared by Vibration Injection

采用自行研制的压力振动注射装置 ,在不同熔体温度、振动频率、振动压力下成型了全同立构聚丙烯振动注射试样 ,并进行了WAXD、DSC和SEM测试。结果表明 ,当成型温度为 190℃时 ,在高的振动频率下 ,有γ晶生成 ;在高振动压力条件下 ,有 β晶生成。当成型温度为 2 3 0℃ ,无论是在高频率 ,还是高压力振动 ,都有 β晶生成。同时 ,振动还将改变试样的熔点 ,提高试样结晶度 ,细化晶粒。

Isotactic polypropylene samples were prepared at various melt temperature, vibration frequency, and vibration pressure using a self-made vibration injector and were characterized using WAXD, DSC and SEM. It showed that when melt temperature was 190 ℃, γ crystal form can be induced at high vibration frequency and β crystal form can be induced at high vibration pressure. When melt temperature was 230 ℃, β crystal form can be induced at both high vibration frequency and high vibration pressure. The vibration may also change the melting points, make the degree of crystallinity higher,and the spherulits finer.