交联结构对阻燃玻纤增强PPE材料热氧老化行为的影响研究

Effect of Crosslinking Structure on the Thermal Oxygen Aging Behavior of Flame-Retardant Glass Fiber Reinforced PPE Materials

深入探讨了阻燃玻纤增强聚苯醚(PPE)材料热氧老化过程中发生两种交联反应,测试了不同厚度材料的凝胶含量,分析了凝胶含量和交联结构与PPE材料在不同热氧老化时间后的拉伸强度保持率之间的关系。研究结果表明:材料的凝胶含量或交联程度与材料的性能保持率之间存在显著的关联,在老化的早期阶段材料的拉伸强度明显下降;随着老化时间的延长和交联反应的进行,材料的交联网络逐步完善,凝胶含量达到平衡;不同厚度的样品在180℃下老化时均出现了有性能保持率的急剧下降,然后逐渐回升的“过冲”现象;而在160℃下老化时,不同厚度样品均表现出了一个明显的性能保持率“平台区”;此外,还观察到材料表层和芯层在热氧老化中表现出不同的行为。综上所述,材料的热氧老化可以分为3个阶段,即老化初期、老化性能修复期和老化性能平台期。

Based upon prior research concerning two distinct crosslinking reactions during thermal oxidative aging of flameretardant glass fiber reinforced polyphenylene ether(PPE)materials,this study expands its scope to assess gel content across materials of varying thicknesses.It examines the interplay between the gel content,crosslinking structure and the post-aging tensile strength retention of PPE materials under diverse thermal oxygen aging conditions.The results showed that the gel content or cross-linking degree of the aged materials are highly related to the performance retention of the materials.In the initial stages of aging,a marked reduction in tensile strength retention is observed.However,as aging time prolongs and crosslinking reactions advance,the materials’cross-linking network steadily matures,achieving gel content equilibrium.Notably,samples of differing thicknesses undergoing aging at 180℃exhibit a phenomenon of performance retention rate"overshoot".Conversely,those aged at 160℃manifest a distinct"plateau"in performance retention rate.Additionally,the material’s surface layer and core layer of the material exhibit distinct thermal oxygen aging behaviors.The thermal oxygen aging process for these materials can be categorized into three stages:early aging,aging performance restoration phase,and aging performance stabilization phase.