基于三元复合抗氧剂体系煤基PP的使用寿命预测研究

Lifetime predication of coal-based polypropylene modified with ternary antioxidant composite system

设计了一系列基于受阻酚类抗氧剂(Irganox®1010、Irganox®1076)、亚磷酸酯类抗氧剂(Irgafos®168)和内酯型碳自由基捕捉剂(Revonox®501)的复配体系,应用于煤基聚丙烯(PP)抗热氧老化性能的改善。通过热台偏光显微镜、差示扫描量热仪(DSC)分析了不同抗氧剂复配体系对PP的影响规律;通过氧化诱导期测试研究了各复配体系对PP抗热氧老化性能的增强效果,利用热失重分析考察了抗氧剂复配体系对PP热降解动力学的作用规律,并对其进行了使用寿命预测。结果表明,与二元复合抗氧剂体系相比,引入碳自由基捕捉剂与主、辅抗氧剂复配,可更显著提高煤基PP的抗热氧老化性能;这一协同增效作用还提高了煤基PP的热稳定性,增加了使用寿命;在最优三元抗氧剂复配比例下,煤基PP在50℃的环境温度下的使用寿命预测高达4.55×10^(5)h。

A series of ternary antioxidant composite systems based on Irganox®1010 and 1076 as main antioxidants,Irgafos®168 as an auxiliary antioxidant,and Revonox®501 as a carbon radical capture agent.These antioxidant composite systems were applied for the modification of coal‑based homopolypropylene(homo‑PP)to enhance its thermo‑oxidative aging performance.The resultant modified homo‑PP samples were evaluated using polarizing optical microscopy,DSC,TGA,SEM and oxidation induction time,and their lifespan was predicted using the parameters obtained from TGA thermal analysis.The results indicated that the ternary antioxidant composite system had a much better enhancement effect on the thermo‑oxidative aging performance of the coal‑based homo‑PP than the binary one,thus resulting in a much greater OIT value.The incorporation of antioxidant composite system slightly enhanced the crystallinity of the coal‑based homo‑PP because the scission of PP molecular chains could be effectively prevented during the melting process.A synergistic effect derived from the ternary antioxidant composite system could improve the thermal stability of the coal‑based homo‑PP and prolong its lifespan at various ambient temperatures.A lifespan prediction demonstrated that the coal‑based homo‑PP modified with an optimal formulation of antioxidant composite system achieved a lifetime of 4.55×10^(5) h at an ambient temperature of 50℃.