Computer Simulation For Crystal Morphology Evolution In Polymer Crystallization Process

The spherulites will be born in the crystallization process of crystalline polymer from melt. The spherulites' density and dimension have a profound effect on the polymer performance of thermodynamics/optics and mechanical behavior. The objective of this thesis is to build a model for the spherulites growth process in quiescent crystallization and dynamic display the growth process. The following works have been finished:1. Based on the assumption of symmetry growth in quiescent crystallization, the crystal morphology model (the induction time model/nuclei model/growth model/impingement model/the relative crystallinity mode) is established for crystalline polymer in quiescent isothermal and nonisothermal crystallization process.2. Based on the theory study, compile the program to dynamic display the process of spherulites growth from nuclei stage to impinge stage with Visual C++. Then, the spherulite's size change will be displayed in picture from small nuclei to a spherulite with big dimension in time.3. Analyze the effect of confectioning condition on the spherulite morphology in quiescent isothermal and no-isothermal crystallization. In isothermal crystallization, analyzed the process in three crystallization temperature .The result indicated the spherulites' density decrease and size increase with the crystallization temperature increasing. In nonisothermal crystallization, calculated the temperature field at the beginning, and then, analyzed the growth process of spherulite in different thickness, boundary temperature and melt temperature. The result indicated that the part's thickness, boundary and melt temperature have a notable effect on the crystallization process.