【摘要】 本文系统开展了两种密度的聚苯醚（PPO）材料在γ辐射（0～1 kGy）和压缩（3%压缩率）耦合作用下的老化实验，研究了吸收剂量和压缩对PPO泡沫材料力学性能、热稳定性、导热性能、表面形貌及化学结构的影响，并利用气体红外光谱揭示了其辐射释放气体的种类及产量。结果表明，γ辐射-压缩耦合老化后PPO泡沫材料弹性模量和导热系数显著增加，样品表层孔结构的坍塌与永久变形是导致这一结果的关键；老化前后样品内部自由基类型和表面官能团结构均无明显变化，样品内部残余自由基浓度由辐射化学过程和吸收剂量所控制；PPO在O₂/N₂气氛下辐解产生CO₂、CO与烷烃，并且受永久变形影响，相对于单独γ辐射老化条件，PPO泡沫材料辐射-压缩老化后CO₂产量略微降低。研究结果对PPO泡沫材料γ辐射-压缩老化机理与服役寿命的评估具有重要意义。更多还原

【Abstract】 This study examines the changes in properties and aging mechanisms of polyphenylene oxide （PPO）foams under two densities when subjected to combined γ-radiation （0–1 kGy） and 3%compression.The investigation focuses on the effects of absorbed dose and compression on various characteristics,including the mechanical properties,thermal stability,thermal conductivity,surface morphology,and chemical structure of PPO foams.The types and yields of gases released during radiation exposure are revealed using gas-phase infrared spectroscopy.The results showed that the collapse and permanent deformation of the surface pore structure in PPO foams following γ radiation and compression aging significantly contribute to increase in elastic modulus and thermal conductivity.No significant changes were observed in the internal radicals or surface functional group structures of the samples before and after aging.The concentration of residual radicals within the samples was influenced by radiation-induced chemical changes and the absorbed dose.Upon radiation exposure and subsequent aging in an O₂/N₂ atmosphere,PPO foams emited CO₂,CO,and alkanes.In addition,the CO₂ yield of PPO foams after radiation-compression aging was slightly reduced due to the permanent deformation caused by compression,compared to γ-radiation aging alone.These findings hold significant value for the evaluation of γ-radiation–compression aging mechanisms and the lifespan of PPO foams.更多还原