超高分子量聚乙烯纤维网紫外线光照老化试验研究

Study on Ultraviolet Light Aging Test of Ultra-high Molecular Weight Polyethylene Fiber Nets

为揭示超高分子量聚乙烯(UHMWPE)纤维网在紫外线光照下的老化规律,通过傅里叶变换红外光谱、扫描电子显微镜、示差扫描量热法和拉伸实验研究了其在不同试验周期紫外线光照后的化学成分、形貌和断裂强力变化等性能。结果表明,紫外光照使超高分子量聚乙烯主链断裂、诱发聚乙烯分子降解;微观形貌由原始的表面平整逐渐产生裂纹和凹坑,断口形貌逐渐变为脆性断裂;力学性能明显降低,断裂强力从原始的850.8 N,经过10个周期的紫外辐照后下降至79.1 N;紫外线照射导致内部C―C键断裂、折叠链结晶的熔融峰降低,辐照高温促进氧分子等从微裂纹和气孔渗入,生成C=O和C―O―C等键,诱发一系列氧化反应的发生,最终导致UHMWPE降解、力学性能降低。

In order to reveal the aging law of ultrahigh molecular weight polyethylene(UHMWPE)fiber net under ultraviolet light,the chemical composition,morphology and strength of UHMWPE fiber net under ultraviolet light were studied by Fourier transform infrared spectroscopy,scanning electron microscopy,differential scanning calorimetry and tensile experiments.The results show that ultraviolet light can break the main chain of ultrahigh molecular weight polyethylene and induce the molecular degradation of polyethylene.From the original surface flatness,cracks and pits appear gradually,and the fracture morphology changes to brittle fracture gradually.The mechanical properties decreased significantly from the original 850.8 N to 79.1 N after 10 cycles of ultraviolet irradiation.Ultraviolet radiation leads to internal C―C bond breakage and a decrease in the melting peak of folded chain crystallization,while irradiation at high temperatures promotes the ingress of oxygen molecules and other gases through microcracks and pores,generating C=O and C―O―C bonds,thereby inducing a series of oxidation reactions.Ultimately,this results in the degradation of UHMWPE and a decrease in its mechanical properties.