等规聚丙烯材料中β晶型相变动力学初探  

Kinetics of structural transformation in β-isotactic polypropylene

作　　者：贾涓[1] 毛卫民[1] Dierk Raabe 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]德国马克思普朗克钢铁研究所,德国杜塞尔多夫40237

出　　处：《武汉科技大学学报》2007年第4期360-363,共4页Journal of Wuhan University of Science and Technology

摘　　要：采用广角X射线衍射法测量了退火及轧制过程中等规聚丙烯材料中结晶度和β相含量的变化规律,分析了β晶型的相变动力学过程。结果显示,在等温退火和轧制过程中,β晶型都是最不稳定的相。当退火温度超过临界温度时,β相才能完全转化为α相。150℃等温退火时,发生的是β相的熔化和α相的再结晶过程,β相与保温时间的关系符合Avrami函数。轧制过程中,β相分别转化为α相和非晶相,两种转化均使β相含量随轧制真应变的增加呈线性减少。The X-ray diffractometer system with an area detector was used to observe the changes of crystallinity and the β phase fraction in isotactic polypropylene （iPP） during annealing and rolling. The kinetics of structural change was analyzed. The results show that the β crystalline phase is the most unstable phase in iPP during isothermal annealing and rolling. The total β-α structural transformation will occur only when the annealing temperature is higher than the critical one. After 150 ℃ isothermal annealing, the relation between the β phase fraction and the ageing time corresponds to the Avrami curve because the structural transformation is the melting of the β crystalline phase and the recrystallization of the α crystalline phase. During rolling, some of the β crystalline transfer to the α crystalline and others transfer to the amorphous. Both transformations lead to the linear decrease of the β phase fraction with the increase of the rolling true strain.

关 键 词：等规聚丙烯(iPP) Α相 Β相 相变 动力学 

分 类 号：TG142.1[一般工业技术—材料科学与工程]