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 μm, 1 μm, 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.

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► We used four different sizes of silica particles ranging from micro- to nano-sizes.
► We examine the particles size effect on PP/SiO2 composites under various strain rates.
► We also investigate the strain rate effect for each of tested PP/SiO2 composites.
► Particle size and strain rate influence the mechanical properties of tested composites.
► Each PP/SiO2 composite shows significant strain rate sensitivity up to certain extent.