Lifetime prediction and aging mechanism of unplasticized polyvinyl chloride filled with calcium carbonate under long-term thermal and oxidative conditions

The successful implementation of the low-carbonization strategy is heavily reliant on the development of low-loss and high-efficiency green antenna technology. However, long-term exposure to high heat and oxygen leads to the degradation of antenna materials and the release of harmful substances. Studies on the aging behavior and mechanism of the antenna materials are of essence to realize the low-carbonization strategy. To address this issue, an unplasticized polyvinyl chloride filled with calcium carbonate (uPVC/CaCO3) has been successfully prepared using the injection molding technique. After that, the aging behavior, mechanism, and working lifetime were comprehensively explored under thermal and oxidative conditions. It is found that the composite maintains a high level of functionality for up to 24 years at 60 degrees C and 4.5 years at 70 degrees C on the impact strength failure criterion. The simultaneous oxidation and dehydrochlorination reaction, cross-linking reaction, and deterioration of the interaction between components are responsible for the aging of the uPVC/CaCO3 composite. These findings provide valuable insights into the development of radome materials for achieving low-loss and highefficiency green antenna technology.