Abstract: This paper reviews advances in the modification of PP-based composites with micro-/nano-sized inorganic rigid particles, with emphasis on reviewing the effects of micro-sized, nano-sized and micro-/nano-sized compounded inorganic particles on the mechanical and functional properties of the PP-based composites. A general conclusion is that the smaller the inorganic particles, the more favorable the composites are strengthened and toughened, and that the modification of the inorganic particles has a critical influence on the interfaces of the composites, which then affect the microstructures and properties remarkably. The addition of micro-sized inorganic particles can improve the impact property and rigidity of the PP-based composites, but usually reduces the strength properties; on the other hand, nano-sized inorganic particles have the ability to enhance the strength, toughness, and modulus of the PP-based composites. The properties of the PP composites filled with compounded fillers are better than those of the PP composites filled with single fillers.

Key words: polypropylene, micro-/nano-sized inorganic rigid particles, strengthening, toughening