阻燃型玻纤增强尼龙10T复合材料的热氧老化行为及热降解动力学

Thermo-oxidative Aging and Thermal Degradation Kinetics of the Flame Retardant Glass Fiber Reinforced Nylon 10T Composites

研究了不同热氧老化温度(160℃、200℃和240℃)和时间(0~50d)对溴化环氧树脂/Sb2O3协效阻燃短玻纤增强尼龙10T复合材料(PA10T/GF/FR)的热氧老化行为以及热降解动力学的影响。采用力学性能测试、SEM、DMA和TGA分析对老化前后复合材料的动静态力学、微观形貌以及热降解行为进行研究,并使用Kissinger和Flynn-Wall-Ozawa两种方法计算了复合材料的热降解活化能。结果表明:老化过程中基体树脂降解分子量降低,纤维与基体界面性能恶化,复合材料力学性能下降;160℃老化过程部分PA10T分子链发生交联反应,储能模量和玻璃化转变温度(Tg)增加,200℃和240℃下Tg先上升后下降,老化后期树脂分子链以降解为主;活化能计算表明160℃老化50d后复合材料热稳定性提升,200℃老化50d以及240℃老化30d后,复合材料结构破坏严重,热降解行为变化显著。此外,阻燃剂的添加能够提升老化试样的热稳定性。

In this paper,the thermal-oxidative aging effects on the thermal oxidation behaviors and thermal degradation kine-tics of flame retardant short-glass-fiber reinforced PA10T composites(PA10T/GF/FR)were investigated with different aging temperatures of 160℃,200℃and 240℃for 0-50 days.The static and dynamic mechanical properties,microstructure and thermal degradation behaviors were investigated by using mechanical properties analysis,DMA,SEM and TGA,respectively.Kissinger and Flynn-Wall-Ozawa methods were utilized to calculate the thermal degradation activation energy of PA10T/GF/FR.The results de-monstrated that during thermal-oxidative aging the molecular weight of PA10T resin declined and the interfacial properties between fiber and matrix deteriorated,resulting in the decrease of mechanical properties.The micro-crosslinking reaction happened during 160℃aging process and thus storage modulus increased as well as glass transition temperature(T g).However,the molecular degradation dominated in the later phase of 200℃and 240℃aging,which resulted in the T g increase first and decrease after.The calculation of activation energy exhibited that the thermal stability of the 50 d aged sample at 160℃was improved,while after 50 d aging at 200℃or 30 d at 240℃,the composite structure was destroyed seriously,and the thermal degradation behaviors changed significantly.What’s more,the flame retardant can enhance the thermal stability of aged samples.