Deng Jiangang, Lan Zhenbo, Xu Zhuolin, Long Wei, Sun Qiang, Nie Yu
Wuhan Nari Limited Liability Company of State Grid Electric Power Research Institute, Wuhan 430206, China.
State Grid Electric Power Research Institute, Nanjing 211106, China.
Polymers (Basel). 2024 Aug 10;16(16):2269. doi: 10.3390/polym16162269.
In this study, two types of composites, polybutylene terephthalate (PBT) and epoxy resin (ER), reinforced with 20% of glass fiber (GF) are used as the comparative research objects. Their mechanical properties after thermal aging at 85~145 °C are evaluated by tensile strength and fracture morphology analysis. The results show that the composites have similar aging laws. The tensile strength of GF/PBT and GF/ER decrease gradually with the increase of aging temperature, while their elastic moduli are independent of the thermal treatment temperature. Scanning electron microscopy study of the fracture surface shows that separation of glass fiber from PBT and ER matrix becomes more obvious at higher aging temperature. The fibers on the matrix surface appear clear and smooth, and the whole pulled out GFs can be observed. As a main mechanical strength degradation mechanism, the deterioration of interface adhesion between the matrix and GF is discussed. A large difference in coefficients of thermal expansion of the matrix and GF is a main factor of the mechanical degradation.
在本研究中，以两种用20%玻璃纤维（GF）增强的复合材料，聚对苯二甲酸丁二醇酯（PBT）和环氧树脂（ER）作为对比研究对象。通过拉伸强度和断裂形态分析来评估它们在85~145 °C热老化后的力学性能。结果表明，复合材料具有相似的老化规律。GF/PBT和GF/ER的拉伸强度随老化温度的升高而逐渐降低，而它们的弹性模量与热处理温度无关。对断裂表面的扫描电子显微镜研究表明，在较高的老化温度下，玻璃纤维与PBT和ER基体的分离变得更加明显。基体表面的纤维显得清晰且光滑，并且可以观察到整个拔出的玻璃纤维。作为主要的机械强度降解机制，讨论了基体与玻璃纤维之间界面粘结的劣化。基体和玻璃纤维热膨胀系数的巨大差异是机械性能降解的主要因素。
