Particle size - Dependent on the static and dynamic compression properties of polypropylene/silica composites

The effect of particle size is widely known as an essential factor that influences the mechanical properties of particulate filled polymer composites. However, there is a limited number of works available, on the particular under dynamic perspective. Based on this, the static and dynamic compression properties of polypropylene/silica composites, with particle sizes of 3 mu m, 1 mu m, 20 nm, and 11 nm, were successfully studied at different levels of strain rates (i.e., 0.01 s(-1), 0.1 s(-1), 650 s(-1), 900 s(-1), and 1100 s(-1)) using a universal testing machine and a split Hopkinson pressure bar apparatus. Results show that the yield strength, the ultimate strength, and the stiffness properties, of polypropylene/silica composites were greatly affected by both particle size and loading rates. Furthermore, particle size also influences the rate sensitivity and the thermal activation volume of polypropylene/silica composites; where, smaller particle recorded lower rate sensitivity. Meanwhile, for the thermal activation volume, the trend was reversed. (C) 2012 Elsevier Ltd. All rights reserved.