Temperature plays a significant role in the degradation and stability of polyethylene PE , which is a widely used thermoplastic polymer. The effect of temperature on polyethylene can be understood in terms of its impact on the chemical structure, physical properties, and overall performance of the material.1. Chemical structure: Polyethylene consists of long chains of carbon atoms bonded to hydrogen atoms. The stability of these chemical bonds is influenced by temperature. At higher temperatures, the energy in the system increases, which can cause the breaking of chemical bonds, leading to the degradation of the polymer. This process is known as thermal degradation and can result in the formation of free radicals, which can further react with other molecules and cause chain scission or cross-linking.2. Physical properties: The physical properties of polyethylene, such as its crystallinity, melting point, and glass transition temperature, are also affected by temperature. As the temperature increases, the polymer chains gain more energy and become more mobile. This can lead to a decrease in crystallinity and an increase in the amorphous regions of the polymer, which can affect its mechanical properties, such as tensile strength and elongation at break.3. Oxidative degradation: Polyethylene is susceptible to oxidative degradation, which occurs when the polymer reacts with oxygen in the presence of heat or light. Higher temperatures can accelerate the oxidation process, leading to the formation of carbonyl groups, hydroperoxides, and other degradation products. These products can further react with the polymer chains, causing chain scission or cross-linking, and ultimately reducing the stability and performance of the material.4. Environmental stress cracking ESC : ESC is a common failure mechanism in polyethylene, where the material cracks under stress in the presence of certain chemicals or environmental factors. Temperature can influence the susceptibility of polyethylene to ESC, as higher temperatures can increase the rate of stress relaxation and the diffusion of chemicals into the polymer matrix, promoting crack formation and propagation.In summary, temperature has a significant impact on the degradation and stability of polyethylene. Higher temperatures can cause thermal degradation, affect the physical properties of the material, accelerate oxidative degradation, and increase the susceptibility to environmental stress cracking. To maintain the stability and performance of polyethylene, it is essential to consider the temperature conditions during processing, storage, and application of the material.