热老化条件对机车电缆绝缘材料机械性能的影响

Effect of Thermal Ageing Conditions on Mechanical Properties of Railway Rolling Stock Cable Insulation Materials

研究了不同热老化条件(热老化温度和热老化时间)对交联聚烯烃机车电缆料机械性能的影响。4种交联聚烯烃机车电缆料分别在120℃、240 h热老化条件和135℃、168 h热老化条件下进行平行热老化机械性能试验,并采用傅立叶变换红外光谱仪(FTIR)分析和扫描电子显微镜(SEM)扫描热老化后的交联聚烯烃机车电缆料微观结构进行表征。试验结果表明:相比135℃、168 h热老化条件,120℃、240 h热老化条件对交联聚烯烃机车电缆料的机械性能影响明显;120℃、240 h热老化条件对交联聚烯烃机车电缆料的C—H键破坏性更大,使材料紧密度下降,同时多处出现不规则孔洞。通过对热老化条件对交联聚烯烃机车电缆料机械性能影响的研究,最终为机车电缆材料选用及电缆生产工艺设定提供理论支撑。

The effect of different thermal ageing conditions(thermal ageing temperature and thermal ageing time)on mechanical properties of crosslinked polyolefin for railway rolling stock cable is studied. Four kinds of crosslinked polyolefin for railway rolling stock cable are carried out parallel experiments under 120 ℃ 240 h and 135 ℃ 168 h thermal ageing conditions respectively. The microstructure of the materials after thermal ageing is characterized by Fourier transform infrared spectroscopy(FTIR) and scanning electron microscopy(SEM). The test results show that the mechanical properties of crosslinked polyolefin for railway rolling stock cable are obviously affected by 120 ℃ 240 h thermal ageing conditions compared with 135 ℃ 168 h thermal ageing conditions, and the C―H bond of the materials are more destructive under 120 ℃ 240 h thermal ageing conditions than under 135 ℃ 168 h thermal ageing conditions, which decreases the compactness of the materials and causes irregular holes in many places. Through the study of the effect of thermal ageing conditions on the mechanical properties of crosslinked polyolefin for railway rolling stock cable, the theoretical support for the selection of railway rolling stock cable materials and the setting of cable production process is provided.