摘要
利用DSC和偏光显微镜研究了三种等规聚丙烯树脂的结晶动力学。这三种树脂具有完全不同的分子量(熔融指数分别为12,35和300)与分子量分布(多分散指数相应为a=4.76,2.16和2.85)。研究发现,在等温结晶条件下,总结晶速率和球晶的生长速率从根本上受到分子量和分子量分布的影响。随熔融指数的增加(即重均分子量的减少),结晶的半值期增加。根据聚合物结晶动力学的理论,得到了平衡熔点T.o和大分越来越子折叠表面的自由能a.,并且发现T.o和O.值随着重均分子量的增加而增加.
The crystallization kinetics of three isotactic polypropylene with different molecular weight(melt indexes 12, 35 and 300 respectively)and molecular weight distributions (correspond polydisperse indexes a =4.76, 2.16 and 2.85)were investigated by DSC and polarized microscope. It was found that the overall isothermal crystallization rates and the growth rates of spherrulites were substantially influenced by the differences in molecular weight and its distribution. The half value period of crystallization increased as the increa- sement of the melt indexes. Based on the theories of the kinetics of polymer crystalli- zation, the values of equilibrium melting point T_m^o and the free energy σ_e of folding surface of macromoleeules were obtained, and it was found that T_m^o and σ_e values are increased as the increasement of weight average molecular weight
出处
《合成纤维工业》
CAS
CSCD
1989年第1期37-43,共7页
China Synthetic Fiber Industry
