聚合物等温结晶过程的模拟实验

Simulation experiment for isothermal crystallization of polymers

采用Monte Carlo法,利用计算机模拟预先成核条件下聚合物的等温结晶过程,研究了影响聚合物等温结晶过程的多种因素,如结晶体系外形、体系体积变化、晶核数目、晶体线生长速率等.基于Avram i方程的计算机模拟实验结果表明:与立方体体系比较,球体体系的结晶速率常数Z和Avram i指数n值更接近理论值;随着体系体积、晶核数目和晶核后期线生长速率的减小,Avram i指数n值随之减小;结晶后期晶核线生长速率的变化使得模拟实验曲线与理论值偏离严重.

The isothermal crystallization process of polymers under the condition of predetermined nucleation is simulated with computers by Monte Carlo method. The factors which affects on the isothermal crystallization process of polymers are researched including the shape of crystallo system, volume changes of this system, the number of the nuclei and the linear velocity of nuclei growth. The simulation results of computers based on the Avrami equation show that the crystallized velocity constant（Z）and Avrami index（n） of the sphere system are more coincident with the theoretical value than those of the cube system. With the decrease of the system height, the number of the nuclei and the linear velocity of nuclei growth, the Avrami index （n） is reduced gradually. The change of linear velocity of nuclei growth makes badly departure from its theoretical value at the later stage of the crystallization.