Enhanced beta-crystallization in polypropylene random copolymer with a supported beta-nucleating agent

摘要

A great number of investigations demonstrated that it is more difficult for polypropylene random copolymer (PPR) to obtain high beta-crystal content. To increase the beta-crystallization in PPR, calcium pimelate (CaPA) supported on the surface of nano-CaCO3 (CC100) was used as a beta-nucleating agent. The crystallization behavior and morphology, melting characteristics and non-isothermal crystallization kinetics of CC100 nucleated PPR were compared with PPR nucleated by aryl amide compounds (TMB-5) and CaPA by DSC, XRD and POM. The non-isothermal crystallization kinetics of PPR and beta-nucleated PPR was examined by Jeziorny and Mo models. The crystallization activation energy and nucleation activity (NE) of PPR and beta-nucleated PPR were calculated according to Friedman and Dobreva methods, respectively. It indicated that the beta-nucleating efficiency of CC100 was higher than those of TMB-5 and CaPA. It is an effective method to enhance the beta-crystallization of PPR with a supported beta-nucleating agent. (C) 2014 Elsevier B.V. All rights reserved.