This paper reported an investigation on the effect of ultraviolet (UV )crosslinking on thermal elongation,mechanical properties and flame retardancy of an insulation material used for low-smoke halogen-free flame-retardant cables.The thermal stability and aging behavior of the insulation material were also studied by thermogravimetric analysis.The results showed that the thermal elongation of insulation material decreases gradually with an increase in UV irradiation time,and its mechanical properties,heat resistance,and flame retardant and electrical performance were greatly enhanced due to UV crosslinking.The tensile strength of the insulation material was improved from 10 MPa to 13 MPa after UV crosslinking.With a thermal aging test at 158 ℃,both the tensile strength and elongation at break achieved a retention rate above 90 %,and the limiting oxygen index also increased from 33.5 % to 35.0 %.Moreover,the volume resistivity and dielectric strength were improved to 7.8×1012Ω·m and 36.0 MV/m from 1.1×1013 Ω·m and 33.0 MV/m before UV crosslinking,respectively%研究了紫外光交联对低烟无卤阻燃电缆绝缘材料的热延伸、力学性能及阻燃性能的影响,并利用热失重分析仪研究了绝缘材料的热稳定性及老化性能.结果表明,随着紫外光辐照时间的延长,绝缘材料的热延伸率逐渐减小,交联后绝缘材料的力学性能、耐热性、阻燃性能及电性能明显提高;紫外光交联后,绝缘材料的拉伸强度由交联前的10.0 MPa增加到13.0 MPa;通过158℃热老化实验,绝缘材料的拉伸强度和断裂伸长率的保留率均大于90%;极限氧指数也由33.5%增大到35.0%;体积电阻率由交联前的7.8×1012Ω·m提高到1.1×1013Ω·m;介电强度由33.0 MV/m提高到36.0 MV/m.
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