Parameter Determination Of Polymer Crystallization Kinetics And Crystallinity Forecast

The crystallization kinetics of polymer is the science on the relation of crystallinity or relative crystallinity with time under various conditions. It can not only provide basis for mastering the crystalline properties of materials and getting prospective structure of condensed state, but also establish academic basis for acquiring optimal processing conditions techniques of crystalline polymer. The following works focused on crystalline properties and effect of techniques condition on the distribution of crystallinity have been finished.1. Research on crystalline properties and crystallization kinetics of the PA6 and UFAPR polymer blend has been made, and the results show that the modes of crystal are the same for PA6 and the PA6/UFAPR blend. UFAPR plays an important role of nucleator in the process of crystallization, and obviously improves the crystalline rate and crystalline temperature of PA6, makes the distribution of crystal grain narrowed.2. According to the crystallization kinetics of polymer and the methods of resolving the crystallization kinetic parameters, analysis of the modern crystallization kinetics model has been studied. It can be concluded that there is not a widely accepted method.3. The kinetics of nonisothermal crystallization of two kinds of LDPE and PP is investigated by DSC, and characterized by three molds of nonisothermal crystallization kinetics. The result demonstrates Avrami equation is not fit to describe nonisothermal crystallization kinetics of four polymer materials. However, the nonisothermal crystallization kinetics of two PP materials can be described by the Ozawa equation. R-t equation can be used to describe nonisothermal crystallization kinetics of four polymer materials on the basis of experiment and the parameters of the materials can be acquired.4.Energy equation and nonisothermal crystallization kinetics mold are combined to study the effect of techniques condition on the distribution of products' crystallinity. It showed that crystallinity decreases at the same mold temperature with the increase of melt temperature; the crystallinity increase under the same melt temperature With the increase of mold temperature. In the direction of thickness, the crystallinity is low in the surface of product, and it reaches a maximum at a certain thickness, then gradually decrease with the increase of thickness, and get the minimum at the middle of the thickness, but the crystallinity at this point is much larger than the value on the surface of product.