Study on the Crosslinking System for Molded-In Foaming (MIF) Process

This study aimed to find a suitable crosslinking system for the molded-in foaming (MIF) process by analyzing the crosslinking behavior of ethylene-co-methacrylic acid copolymer (EMAA) with zinc oxide (ZnO) and dicumyl peroxide (DCP) as crosslinkers using oscillating disc rheometer (ODR). DCP was not suitable for MIF process due to its fast initial torque rise rate. For ZnO, a significant torque change was observed at 5 phr or higher, and even when it showed a similar maximum torque value to DCP, it was judged to be more suitable for the MIF process than DCP because of its low initial torque value increase rate. When DCP was added to 15 phr of ZnO, it was possible to increase the maximum torque value while keeping the initial torque increase low, so it was judged that the ZnO/DCP composite crosslinking system was more useful for the MIF process than DCP and ZnO alone.