ASSESSING POLYMER CRYSTALLIZABILITY FROM NONISOTHERMAL CRYSTALLIZATION BEHAVIOR

Crystallization of polymers plays an important role in polymer process ing because the structure developed during crystallization influences the mechanical and physical properties of the polymer product. The cry stallization of polymers takes place under nonisothermal conditions du ring 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 t he inherent crystallizability of the polymer and its sensitivity to pr ocessing conditions is reported. The polymers used in the present inve stigation include various grades of polyethylenes and polypropylenes. It is shown that a simple graphical analysis of the nonisothermal crys tallization parameters can be used to quantify the inherent crystalliz ability of polymers and sensitivity of its structure development to ch anges in the cooling rates.