PP/EPDM-based dynamically vulcanized thermoplastic olefin with zinc dimethacrylate: Preparation, rheology, morphology, crystallization and mechanical properties

Abstract

Dynamically vulcanized thermoplastic olefin (TPO) based on polypropylene (PP)/ethylene-propylene-diene (EPDM) loaded with zinc dimethacrylate (ZDMA) was prepared. The addition of ZDMA significantly improved the complex viscosity of the resulting material in the melt state, as determined from rheological analysis. Dynamic mechanical analysis (DMA), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were performed to evaluate the structure, as well as to characterize the morphology formed during dynamic vulcanization. The ZDMA improved the crosslinking of the rubber phase and resulted in crosslinked rubber particles with dimensions within 200 nm. The addition of ZDMA improved the compatibility between rubber and PP phases, which contributed to the enhanced mechanical and rheological properties. The crystallization behavior analysis indicated that the addition of ZDMA promoted the nucleation process of PP, but a higher ZDMA content showed a negative effect on the crystallinity of the PP component. Remarkable improvements in toughness and extensibility of PP/EPDM/ZDMA composites were achieved.