Mechanical Properties of Nanocomposites from Ball Milling Grafted Nano-Silica/Polypropylene Block Copolymer

Polymer based nanocomposites, in which inorganic nanoparticles are dispersed in organic polymer matrices, have attracted materials scientists’ attention owing to their unique properties, resulting from their nano-scale microstructure. Because of their large surface area, nanoparticles interact with the polymer matrix and carry a load effectively. The mechanical properties of these composites can be significantly improved at low filler content if the ultrafine phase dimensions of the nanoparticles are maintained1, 2. To make successful nanocomposites, it is very important to be able to disperse the nanoparticles throughout the matrix. However, a homogeneous dispersion of nanoparticles is very difficult to achieve, because they have a high surface energy, and tend to agglomerate. Moreover hydrophilic nanoparticles are incompatible with hydrophobic polymers. Consequently, a number of loose clusters of particles appear in the composite materials and lead to properties even worse than those of conventional inorganic/organic systems. To break up the agglomerates, researchers have proposed two approaches: (a) in-situ polymerisation of monomers in the presence of nanoparticles3 and (b) intercalation polymerisation techniques4. Although nanoparticles can be dispersed uniformly, these methods involve complex processing procedures, special conditions and high cost and are limited to a laboratory scale. In Mechanical Properties of Nanocomposites from Ball Milling Grafted Nano-Silica/Polypropylene Block Copolymer