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

• PPR were nucleated by aryl amide compounds (TMB-5), CaPA and CC100.
• The non-isothermal crystallization kinetics of PPR and β-nucleated PPR was studied.
• The crystallization activation energy was calculated according to Friedman method.
• The nucleation activity (NE) was calculated according to Dobreva method.
• We found that the nucleation efficiency is CC100 > CaPA > TMB-5.

A great number of investigations demonstrated that it is more difficult for polypropylene random copolymer (PPR) to obtain high β-crystal content. To increase the β-crystallization in PPR, calcium pimelate (CaPA) supported on the surface of nano-CaCO3 (CC100) was used as a β-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 β-nucleated PPR was examined by Jeziorny and Mo models. The crystallization activation energy and nucleation activity (NE) of PPR and β-nucleated PPR were calculated according to Friedman and Dobreva methods, respectively. It indicated that the β-nucleating efficiency of CC100 was higher than those of TMB-5 and CaPA. It is an effective method to enhance the β-crystallization of PPR with a supported β-nucleating agent.

The Kβ values of β-nucleated PPR as a function of cooling rate (PPA, PPB and PPC represent PPR nucleated by CaPA, TMB-5 and CC100, respectively).Figure optionsDownload as PowerPoint slide