Storage Life Evaluation and Aging Mechanism Analysis of Epoxy Resin Potting Materials

Abstract

The tensile shear samples of potting epoxy resin materials were accelerated under 90°C, 100°C and 110°C temperature conditions. The tensile shear strength was used as the aging characteristic index during the aging test. After normalizing the data in the descending section, the storage life evaluation and analysis is performed based on the Arrhenius model. The retention rate of tensile shear strength is 50% as the critical failure condition. The storage life at 25°C is predicted to be 21.7 years. During the thermal oxygen aging process, the epoxy bonding material’s adhesive interface first undergoes post-curing reaction under the action of heat, and then undergoes oxidative degradation under the action of thermal oxygen. The sample interface is more susceptible to oxidative degradation than the interior. In the oxidative degradation stage, the part of the epoxy resin connected to the hydroxyl group is oxidized to the aldehyde group, and the methylene group connected to the N in the curing agent is oxidized to C=O, forming C=O in the amide, and the molecular backbone is broken And produce low molecular weight polymers.