物理老化对高性能热塑树脂酞侧基聚芳醚酮(PEK-C)长期使用行为的影响

Physical Aging Effect on the Long - term Behavior of High - Performance Thermoplastics

物理老化是大多数高分子材料在使用过程中特别是在高温环境中不可避免发生的热力学 过程，其发生的速率快慢和程度大小都直接影响这类材料的使用性能，进而影响其使用寿命．因此 对物理老化过程的预测是这类材料应用的要求．本文用示差扫描量热（ＤＳＣ）技术，通过研究高性能 热塑树脂酞侧基聚芳醚酮（ＰＥＫ－Ｃ）在高温物理老化过程中其玻璃化转变温度（ Ｔｇ）随老化时间的 变化规律，所似模拟了老化初始阶段ＰＥＫ－Ｃ的Ｔｇ与老化温度（ Ｔａ）和老化时间（ｔａ）的关系，并运 用所得的参数预测了ＰＥＫ－Ｃ在正常使用温度下物理老化发生的可能性及程度，为确定这类材料 使用寿命打下了基础．

The developments of physical aging in phenolphthalein poly(aryl - ether - ketone) (PEK - C) with time at two aging temperatures up to 20K below glass transition temperatures (Tg≈495 K ) have been studied using differential scanning calorimetry(DSC). Substantial relaxation within the aging course of several hours was observed by detecting Tg decreasing during physical mug process at the two aging temperatures. The relasxation process is extremely non - linear and self- retarding. The time dependency of enthalpy during the initial stages of annealing was approximately modeled using the Narayanaswamy- Toool model. The structure relaxation parameters obtained from this fitting were used to predict the possibility of physical aging occurring at using temperature for long - term pur-pose.