Structural Investigations of Propylene/Ethylene Random Copolymers by Thermal Fractionation Technique

Stepwise Isothermal Segregation Technique (SIST) has been applied to four C3C2 random copolymers with very similar ethylene content and molecular weight distribution but generated by using different Ziegler-Natta catalysts in order to test the capability of such technique to discriminate among molecular structures. On the basis of obtained results it was possible to demonstrate the sensibility of SIST to both inter- and intra-molecular defects impressed to the polymers by the different catalytic systems.