Effect of hydrophobic nano-silica/β-nucleating agent on the crystallization behavior and mechanical properties of polypropylene random copolymers

In this work, hydrophobic nano-silica (SiO₂) and β-nucleating agent are incorporated into polypropylene random copolymer (PP-R) matrix by melt blending. The effect of the content of nano-SiO₂/β-nucleating agent on the crystallization and mechanical behaviors of PP-R was investigated in detail. For a nano-SiO₂ content of 0.5 wt% and a β-nucleating agent content of 0.5 wt%, the tensile strength and impact strength of the composite were in a more balanced position. Regarding isothermal and non-isothermal crystallization experiments, nano-SiO₂/β-nucleating agent significantly accelerated the nucleation and growth of crystallites with a synergistic nucleation effect. Also, the crystallization kinetics of PP-R/nano-SiO₂/β-nucleating agent, PP-R/nano-SiO₂ and PP-R/β-nucleating agent composites were analyzed and compared using the Avrami equation. The results showed that the PP-R/nano-SiO₂/β-nucleating agent composites have better crystallization rate and shorter semi-crystallization time. This study shows far-reaching theoretical and practical implications for accelerating the development of new high-performance PP-R materials. © 2023 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Industrial Chemistry.