A Strategy to Develop Homo-polypropylene Composites with High Impact and High Rigidity

One of the significant drawbacks of polymer toughening is the trade-off between improved toughness and reduced rigidity. Based on our previous research (Li et al. Polymer, 2020, 191, 122237), to produce rubber particle-toed polymer composites with high impact and low rigidity loss, it is best to have a high modulus for the core and a low modulus for the shell. The question is whether we can construct high-impact polymer composites while maintaining or increasing their rigidity by increasing the core modulus. Here, SiO2/POE core–shell particles are used to toughen the polymer composites. According to theoretical analysis, the modulus of the composites can be much higher than that of the polymer matrix. Additionally, the rigidity of the PP composites is greatly influenced by the composition of the core (SiO2) and shell (POE) materials, as well as the amount of SiO2/POE core–shell particles. Experimentally, a PP composite with a high impact and high rigidity is successfully fabricated. The notched impact strength is 44.6 kJ/m2, and the flexural modulus is 1644 MPa, consistent with the theoretical calculations. To the best of our knowledge, this is the highest-performing PP composite with excellent impact strength and rigidity.