红外光谱法在研究硫磷型合成齿轮油性能衰变中的应用

STUDY OF PERFORMANCE DEGRADATION OF SYNTHETIC SULFUR-PHOSPHORUS TYPE GEAR OIL BY FT-IR

利用傅里叶变换红外光谱仪分析了氧化前后的合成齿轮油,确立了试验油氧化吸收峰位在波数1 724~1 684cm^(-1)范围;通过分析不同硫剂含量的基础油,确立了波数在1 130~1 080cm^(-1)和920~870cm^(-1)处为硫化烯烃C—S键的特征吸收峰位置;通过分析不同含量的磷系添加剂,确立了波数在1 100~925cm^(-1)和700~640cm^(-1)处为P—O—C键和P=S键的特征吸收峰位置。利用红外光谱法对某机车齿轮油(GL-5 75w-90)在使用过程中的性能衰变进行研究,结果表明:基础油的氧化在100 000km前递增较快,100 000km后变化趋势平稳;极压抗磨剂不断降解,其中磷剂的降解更快,起主要作用的官能团是P=S基团。

The FT-IR spectrometer was used to characterize the performance changes of gear oil and relative additives. The results indicate that the absorption band of a gear oil before and after oxidation is in 1 724 1 684 cm ^-1. And that the wave number ranges of C--S groups in sulfurized olefin locate in ranges of 1 130 1 080 cm-1 and 920 870 cm-1,and the P--O -C groups is in 1 100 925 cm 1 and P=S groups in 700--640 cm 1. By FT-IR,the degradation of a locomotive gear oil （GL-5 75w-90） was studied. The results show that the oxidation of gear oil increases faster within 100 000 km and becomes flat after 100 000 km. The continuous degradation of extreme pressure antiwear additives occurs for both S and P containing additives. The later is faster,in which the P=S groups play a main role in the degradation process.