Comparison of the Crystallization Behavior of Ziegler-Natta and Metallocene Catalyzed Isotactic Polypropylene

The crystallization behavior of three metallocene catalyzed isotactic polypropylenes were compared to that of a Ziegler-Natta catalyzed resin. The differences in behavior between the two type of resins are suggested to be a result of the differences in molecular microstructures of the resins. Characterization of the molecular microstructures suggest that the miPP resins have a more uniform defect distribution from chain to chain, compared to the zniPP resin.