Improvement of tensile properties of nano-SiO2/PP composites in relation to percolation mechanism

Low nano-silica loaded polypropylene composites are produced by conventiona l compounding technique in which the nanoparticles are grafted by polystyre ne using irradiation beforehand. A high interfacial stress transfer efficie ncy is demonstrated by both strengthening and toughening effects perceived in tensile tests. The role of the modified nanoparticles in improvement of tensile properties of the nano-composites is discussed in terms of percolat ion concept. A double percolation of yielded zones is presented to explain the specific influence generated by the nano-SiO2 particles at low-filler l oading regime. (C) 2001 Elsevier Science Ltd. All rights reserved.