Mechanical properties of polymer blend reinforced with nano silica

Unsaturated polyester resin widely separated because of its low cost and its good physical properties. To get higher impact resistance, it has been blended with natural rubber (NR), for the weight ratio (UP 80 / NR 20) % and reinforced with different loading of nano silica with particle size (20nm) ranging from 0 to 5wt% were prepared by hand – layup method, and were characterized for their SEM. The nanocomposites’ mechanical properties like: impact strength, tensile strength, and hardness were studied as a function of filler loading. All of these mechanical properties values were increased with increasing the filler concentration. The results showed averages of (18%, 90% and 39%) increase in tensile strength, impact strength and hardness respectively compared to pure blend. SEM image of 5wt% amine-ilica/UP/NR showed that there is a free space between the small clusters of the nano silica agglomerations. And in the case of unfilled UP/NR blend there was a very limited plastic deformation because of Presence of UP matrix around the rubber particles. Keywords: Natural rubber, Unsaturated polyester, nano silica, mechanical properties, Nanocomposites.