Abstract:

Polyolefin materials, a widely used class of synthetic plastics, are susceptible to thermal-oxidative aging due to their exposure to hot air and oxygen during usage. This aging process can reduce material durability, ultimately affecting their service life. In this paper, the thermal-oxidative aging mechanism of polyolefin materials was introduced with a particular focus on the hydrogen atom transfer reaction, which served as the pivotal process in elucidating the aging mechanism. The protection mechanism, advantages and limitations of various antioxidants were discussed, elucidating their impact on the aging process. Thermal-oxidative aging of polyolefin materials led to alterations in their properties, which can be categorized into three distinct aspects: apparent changes, thermal properties and mechanical behaviors. The analysis encompassed life prediction methodologies for polyolefin materials, categorizing them into those utilizing a single performance metric and those incorporating multiple performance metrics. Finally, for future research on polyolefin thermal-oxidative aging, this work proposed several suggestions aimed at enhancing the theoretical foundation for lifespan regulation of these materials, including developing a comprehensive aging theory from the atomic level, quantifying the correlation between microstructures and macroscopic properties, and integrating multiple performance metrics to refine lifetime prediction accuracy.

Key words: thermal-oxidative aging, aging mechanism, radical, physicochemical properties, life prediction

摘要：

聚烯烃材料是一类应用广泛的合成塑料，由于在使用过程中容易暴露在热空气和氧环境中产生热氧老化现象，导致材料耐久性降低，进而影响其服役寿命。本文介绍了聚烯烃材料的热氧老化机理，其中氢原子转移反应是分析老化机理的关键。讨论了不同抗氧剂的防护机理和优缺点，明晰了抗氧剂对老化进程的影响。分别从表观性能、热性能、机械性能三个方面阐述了热氧老化引起的聚烯烃材料特性的变化。分析了聚烯烃材料的寿命预测方法，包括基于单一性能参数和基于多性能参数的寿命预测方法。最后，针对未来的聚烯烃热氧老化研究工作，提出了从原子尺度建立完整老化理论体系、建立微观结构与宏观性能之间的量化关系和结合多性能参数提高寿命预测准确度等建议，以期为聚烯烃材料的寿命调控提供理论参考。

关键词: 热氧老化, 老化机理, 自由基, 理化特性, 寿命预测