Effect of Drawing Induced Dispersion of Nano-Silica on Performance Improvement of Poly(propylene)-Based Nanocomposites

A new route that combines graft pre-treatment and drawing techniques with melt mixing to prepare nano-particle-filled thermoplastic polymer composites is reported. Nano-SiO 2 particles are first modified by graft polymerization and then the grafted nanoparticles are melt-compounded with poly(propylene) (PP) to produce composite filaments via drawing. Finally, the filaments are injection molded into bulk materials. Because the proposed manufacturing method is able to induce separation of the nanoparticles and the formation of beta-crystals in the PP matrix, the resultant PP-based nanocomposites are much tougher than the unfilled polymers, as characterized by either static or dynamic tests, in addition to showing a simultaneous increase in strength and stiffness.