Preparation and Characterization of New Micro-Composites Derived from Polyamide and Silica Sol

Abstract

Abstract New class of inorganic-organic hybrid micro-composites were prepared by the introduction of different proportions of colloidal silica particles into the polyamide matrix. Poly(phenyleneterephthalamide) was prepared by reacting a mixture of m- and pphenylenediamines with terephthaloyl chloride in dimethyl acetamide. Colloidal silica particles were obtained separately through sol-gel process by controlling the hydrolysis and condensation steps using tetraethoxysilane, ethanol, fuming HCI and water. Various proportions of the resulting sol were mixed with the polymer' solution. 1% aminophenyltrimethoxysilane was added as a coupling agent in each case. Films were cast by evaporating the solvent and these films up to 5% WI. silica were yellow, tough and transparent, whereas the films with 7.5% wt. silica or more were off-white in color and opaque. Mechanical properties of these films were analyzed. The values of tensile strength, maximum strain at rupture, initial modulus and toughness were initially ...