β-PP的结晶和熔融行为  

Crystallization and Melting Behaviors of β-PP

作　　者：朱文利[1,2] 刘祯[1,2] 

机构地区：[1]湖北文理学院机械与汽车工程学院,湖北襄阳441053 [2]汽车零部件制造装备数字化湖北省协同创新中心,湖北襄阳441053

出　　处：《塑料》2015年第5期18-21,共4页Plastics

基　　金：襄阳市科技计划研究与开发项目(襄科业(2013)66号);湖北省自然科学基金(2014CFB456)

摘　　要：通过差示扫描量热法(DSC)研究了冷却速率、加热速率以及等温结晶温度和时间等参数对一种市售β-PP形成β晶相对含量的影响。在非等温结晶过程中,较慢的冷却速率有利于β晶的生成和完善;在加热过程中,由于β晶不稳定引起的β-α转变会影响DSC测试结果:升温速率越低,β-α转变越显著,但升温速率过快又会影响DSC的分辨率。研究结果表明:利用10℃/min的升温速率进行β晶相对含量的测试和计算较合理;在等温结晶过程中,β-PP的最佳等温结晶温度是130℃。在该温度下进行等温结晶,只需5 min即可使β-PP的β晶相对含量高达90%,若继续提高等温结晶时间,可以进一步提高β晶相对含量。The effects of parameters including cooling rate, heating rate, isothermal crystallization tmnperature and time on the relative β crystal content of a commercialized β - PP were studied by using the differential scanning calorimetry （ DSC）. During the non-isothermal crystallization, the slower cooling rate was good for formation and perfection of βcrystals. During heating process, DSC testing results would be influenced by β - ℃ transition due to the instability of β crystal. The slower the heating rate, the more obvious of β - αtransition was. However, resolution of DSC would be reduced if heating rate was relatively high. The study results showed that the heating of 10 ℃/min was reasonable for measuring and calculatingβ relative crystal content. During the isothermal crystallization, the optimum isothermal crystallization temperature was 130 ℃ for the selected β - PP. Under this temperature, it took only 5 min to make β - PP with 90% βcrystals. The relative β crystal content could be further increased if isothermal crystallization time was increased continuously.

关 键 词：聚丙烯 结晶 Β晶 Kd值 β-α转变 

分 类 号：TQ325.14[化学工程—合成树脂塑料工业]