Lifetime Prediction and Aging Mechanism of Glass Fiber Reinforced Acrylate‐Styrene‐Acrylonitrile/Polycarbonate Composite under Hygrothermal Conditions

Abstract The development of fifth‐generation technology has resulted in increased demand for materials with low dielectric losses and superior thermal and mechanical properties. However, ensuring the widespread use of such materials by investigating their aging mechanisms and operating lifetimes remains challenging. In this study, a glass‐fiber (GF)‐reinforced acrylate‐styrene‐acrylonitrile/polycarbonate (ASA/GF/PC) composite is designed and comprehensively investigated its aging behavior, mechanism, and service lifetime under long‐term hygrothermal conditions. Based on the general Peck model, the composite maintains a high level of quality for over 10 years, including under harsh conditions of 40 °C and 80% relative humidity. The aging mechanism is primarily ascribed to cracking between the GF fibers and matrix, the breaking of chemical bonds, the generation of new cross‐linked domains, and physical aging. These findings provide valuable insights into the long‐term utilization of ASA/GF/PC composites in harsh environments.