Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Weathering mechanism of MVQ/g-Opal@CeO2 composites in extreme dry heat environments.

ABSTRACT
This study conducted a comprehensive comparative analysis of the mechanical properties, surface morphology, hydrophobicity, microstructure, and crystallization behavior of methyl vinyl silicone rubber (MVQ) and its composites (MVQ/opal and MVQ/g-opal@CeO2) under both extreme dry-heat and natural aging conditions. The results demonstrated that the incorporation of g-opal@CeO2 significantly improved weathering resistance. Under extreme dry heat aging, the MVQ/g-opal@CeO2 composite exhibited a tensile strength loss of only 7.13% and a hardness increase of 4.6 HA, significantly superior to the 13.05% loss and 6.4 HA increase in pure MVQ. Similarly, during natural aging, the composite showed a minimal tensile strength decline of 5.0% compared to 10.44% for MVQ, while maintaining a high contact angle (decreasing only from 123° to 120°). These improvements were attributed to the combined effects of Ce3+/Ce4+ redox-mediated oxidative protection and UV absorption, which effectively delayed Si–C bond degradation and suppressed the formation of Si–O–Si network structures. Furthermore, prediction models based on Back Propagation (BP) neural networks were developed to characterize the evolution of tensile strength, achieving determination coefficients exceeding 0.9 under both conditions.