Abstract: This review was about polypropylene/nano-silicon dioxide composites with their preparation, compatibility, and toughening/reinforcing mechanism introduced. The preparation methods included in-situ polymerization, sol-gel, and ultrasonic procedure. The mechanism involved in toughening of polypropylene matrix by the nanoparticles included cracks/craze mutual transformation, physical chemistry process, and critical ligand thickness. The mechanical properties of the composites could be further increased through surface modification of the nano-particles to reduce the interface energy, increase the wetting and binding, and regulate its hydrophobicity.

Key words: polypropylene, nano silicon dioxide, composite, compatibility, reinforcement, preparation, toughening, mechanism