The Influence of Biaxial Orientation on the Mechanical Properties of Polyethylene Filled with ZnO Nanoparticles

The influence of biaxial orientation on the mechanical characteristics of polypropylene filled with ZnO nanoparticles was studied. The experimental method of biaxial orientation of composite was developed. The film of filled composite was compressed between two thick disks made of lead/tin alloy; the deformation was determined by alloy. The nanocomposite material contained particles characterized by size <= 30 nm. The increase in content of particles led to the significant increase in yield point; it was explained by crystallization of polypropylene on filler particles. The nonoriented composite exhibited brittle rupture at the degree of filling equal to 20 vol %. The rupture took place owing to the emergence of a craze-like crack; polymer flow was localized within the zone characterized by width about 10 mu m. Preliminary orientation at twofold degree of deformation already allowed preserving plasticity of composite containing up to 30 vol % of particles.