Silicone rubber materials often face alternating hot - humid environments in practical applications, such as in outdoor electrical equipment and ships. Alternating hot - humid environments can accelerate the aging of silicone rubber, affecting its performance and service life. Therefore, studying the aging behavior of silicone rubber in alternating hot - humid environments and establishing an accurate life prediction model are of great significance.
In an alternating hot - humid environment, the periodic changes in temperature and humidity have a complex impact on the aging of silicone rubber. Under high - temperature and high - humidity conditions, water molecules can easily penetrate into the interior of the silicone rubber and undergo hydrolysis reactions with the silicone rubber molecular chains, especially damaging the silicon - oxygen bonds (Si - O). At the same time, the hot - humid environment also promotes the diffusion of oxygen into the silicone rubber, accelerating the oxidation reaction and leading to the degradation and cross - linking of molecular chains. In the low - temperature stage, the movement of silicone rubber molecular chains slows down, and internal stress concentrates, further aggravating the material damage. As the number of alternating hot - humid cycles increases, aging phenomena such as cracks and discoloration gradually appear on the surface of the silicone rubber, and its mechanical properties such as tensile strength and elongation at break gradually decline. Studies have found that after 100 alternating hot - humid cycles, the tensile strength of ordinary silicone rubber can decrease by 20% - 30%, and the elongation at break can decrease by 30% - 40%.
To accurately describe the aging behavior of silicone rubber in an alternating hot - humid environment, researchers have established various life prediction models. Among them, the model based on reaction kinetics is more commonly used. This model considers the relationship between the rates of aging reactions such as hydrolysis and oxidation and temperature and humidity. By experimentally measuring the aging reaction rate constants under different conditions and combining theories such as the Arrhenius equation, a life prediction model is constructed. For example, by measuring parameters such as the mass loss and mechanical property changes of silicone rubber at different temperatures and humidities, the activation energy and reaction order of the aging reaction are determined, and then the service life of silicone rubber in an actual alternating hot - humid environment is predicted. However, this model requires a large amount of experimental data support and has certain limitations in considering complex environmental factors.
In recent years, artificial intelligence technology has been applied in the field of silicone rubber life prediction. Using neural network algorithms, the initial performance parameters of silicone rubber, alternating hot - humid environment parameters (temperature, humidity, cycle period, etc.), and monitoring data during the aging process (such as mechanical property changes and microstructural changes) are input. Through model training, it can learn the complex relationship between these factors and the aging of silicone rubber, thereby realizing the prediction of the silicone rubber's service life. Compared with traditional models, the artificial - intelligence - based model can better handle the complex situation of multi - factor coupling and improve the accuracy of life prediction. However, this model has high requirements for data volume and computing resources, and the interpretability of the model needs further improvement.
By continuously and deeply studying the aging behavior of silicone rubber in an alternating hot - humid environment and optimizing and improving the life prediction model, scientific basis can be provided for the reliability evaluation and reasonable material selection of silicone rubber materials in practical applications, which helps to extend the service life of silicone rubber products, reduce maintenance costs, and ensure the safe and stable operation of related equipment.
Silicone Rubber for ultra-high voltage cable
