热氧老化对聚醚醚酮结构与性能的影响

Effect of Thermal Oxidative Aging on the Structure and Properties of Poly(ether-ether-ketone)

聚醚醚酮(PEEK)作为工程材料广泛应用于多个领域,研究其热氧老化规律对其材料服役优化具有重要意义。采用傅里叶变换红外光谱(FT-IR)、X射线光电子能谱(XPS)、X射线衍射、差示扫描量热和万能拉力机等测试了PEEK片在310℃高温环境中热氧老化不同时间后化学结构及性能的变化。结果表明,在实验老化时间范围内,FT-IR谱图中未出现新的红外吸收峰;XPS谱图显示样品表面形成了氧化产物,且老化168 h的氧化程度达到最大;样品的结晶温度、熔融焓及结晶度均随着热老化时间的延长而减小,在老化504 h后结晶度降为9.7%;老化样品的断裂伸长率随着热老化时间的延长而减小,断裂应力在热老化96 h范围内呈上升趋势,随后逐渐降低。

Poly(ether-ether-ketone)(PEEK)is widely used as engineering material in many fields.It is of great significance for its service optimization to study the thermal oxidative aging of PEEK.Fourier transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),differential scanning calorimetry(DSC)and a universal tension machine were used to test the variation of different time of thermal oxidative aging on the chemical structure and properties of PEEK sheets at 310℃.The results show that no new infrared absorption peaks appear in the FT-IR spectra within the aging time range;XPS spectra show that oxidation products were formed on the surface of the samples and the oxidation degree reaches the maximum after aging time for 168 h.The crystallization temperature,melting enthalpy and crystallinity of the samples decrease with the increasing aging time,and the crystallinity decreases to 9.7% after aging time for 504 h.The elongation at break of the samples decreases with the increasing aging time.The tensile stress increases within the range of 96 h of thermal oxidative aging,and then decreases gradually.