Effect of Void Volume on the Tensile Modulus of Oriented Polypropylene Filled with Surface Modified Calcium

Abstract

An investigation has been made of the relation between void volume and tensile modulus of oriented polypropylene filled with surface modified calcium carbonate. The modifiers are phosphate ester, titanate coupling agent and stearic acid. The void volumes of surface modified filler systems are smaller than those of unmodified ones, irrespective of filler size and filler content. The relative modulus of oriented composites, E_c^d/E_r^d (wherein E_c^d, E_r^d are modulus of oriented composites and modulus of oriented polymer matrix, respectively, ) can be simply expressed as a function of void volume formed by drawing, irrespective of modifiers.