流延聚丙烯的结晶结构

Crystal structure of casting polypropylene

通过DSC和WAXD讨论了结晶温度、拉伸和冷却方式对流延聚丙烯结晶结构特别是γ晶形成的影响.结果表明:拉伸作用提高了试样的结晶度,但对γ晶的形成几乎没有影响;快速冷却不利于γ晶的生成;在95℃和115℃等温结晶的样品中发现了γ晶,且在115℃下生成γ晶更明显.

The crystal structures of several casting polypropylenes were characterized with differential scanning calorimetry （DSC） and wide angle X-ray diffraction （WAXD）. The effects of temperature, draw ratio and cooling rate on crystal structure were discussed. The main conclusions were listed as follows： drawing could increase the crystallinity of casting polypropylene, but could not induce the formation of the γ-form. Temperature and cooling rate could affect the formation of the γ-form. The slower the cooling rate, the more easily the γ-form developed; γ-form was found in the samples crystallized at 95 and 115℃ and the γ-form content of the sample at 115℃ was higher than that at 95%. Key words：