ASSESSING POLYMER CRYSTALLIZABILITY FROM NONISOTHERMAL CRYSTALLIZATION BEHAVIOR

Crystallization of polymers plays an important role in polymer processing because the structure developed during crystallization influences the mechanical and physical properties of the polymer product. The crystallization of polymers takes place under nonisothermal conditions during processing. Hence, the study of nonisothermal crystallization is essential for optimizing the processing conditions to obtain a product with desired properties. A simple approach based upon analysis of the nonisothermal crystallization behavior of a polymer to characterize the inherent crystallizability of the polymer and its sensitivity to processing conditions is reported. The polymers used in the present investigation include various grades of polyethylenes and polypropylenes. It is shown that a simple graphical analysis of the nonisothermal crystallization parameters can be used to quantify the inherent crystallizability of polymers and sensitivity of its structure development to changes in the cooling rates.