CaCO_3级配填充PP结晶形态和非等温结晶动力学的研究

THE STUDY OF MORPHOLOGY OF CRYSTALLIZATION AND NON-ISOTHERMAL CRYSTALLIZATION KINETICS OF PP FILLED WITH CaCO_3 BY DIFFERENT SIZE AND SIZE DISTRIBUTION

将粒径分别为325mesh和1500mesh的CaCO3粒子按照不同比例进行混合级配,并以30%(质量)的填充比例填充聚丙烯。在以DSC和偏光显微镜对样品的结晶形态和非等温结晶动力学的研究中发现,经过合理的级配可以使填充复合材料中PP球晶半径明显增大,晶体排列更为有序;并可使PP的非等温结晶动力学参数K值下降,Avrami指数n和结晶半衰期t1/2上升。文中还运用合理的级配可有效促进复合材料体系粘度下降等实验结果对上述现象进行了合理的解释。

In this paper, two sizes of CaCO_3, 325 mesh and 1500 mesh, were blended by different proportion and filled into PP according to 30%. Differential scanning calorimeter and polarizing microscope were used to investigate morphology of crystallization and non-isothermal crystallization kinetics of the samples. The results show that the samples of efficient filler size and size distribution lead to high crystalline order and large crystallite dimension, while their crystallization rate constants(K) decrease and their Avrami exponents(n) and crystallization half-life(t__(1/2)) increase, compare with the samples of single filler. The experimental results were explained by decreasing of viscosity by samples of efficient filler size and size distribution.