| The thesis describes the effect of processing conditions and various blowing agents on injection molded nylon foams. The types of chemical blowing agents investigated were endothermic: $rm Safoamspcircler$ RPC and exothermic: Expandex 5PT. Two different grades of nylon were used, namely nylon 6 and nylon copolymer. Six different processing conditions were used. It was found that exothermic blowing agent, i.e., $rm Expandexspcircler$ 5PT led to greater amount of density reduction, as low as 50%, but poorer cell structure. Whereas, the use of endothermic blowing agent, $rm Safoamspcircler$ RPC, resulted in lower amount of density reduction (about 40%) but uniform cell structure with smaller cells. It was observed that, as the density was reduced, the cell size increased and the solvent (fuel) resistance decreased. Nylon 6 foams had better solvent resistance than nylon copolymer foams. |
