聚α-烯烃和双酯类航空润滑基础油黏度/颜色衰变分析

ANALYZING ON VISCOSITY/COLOR DETERIORATION OF POA AND DIESTER AVIATION LUBRICATING BASIC OILS

采用高温高压反应釜装置模拟了聚α-烯烃(PAO)和己二酸二异辛酯(DIOA)航空润滑基础油高温工作环境,结合GC/MS技术分析了两种基础油及170,200℃和300℃反应油样的结构组成。在300℃时,PAO呈淡黄色,酸值(KOH)为0.493mg/g,黏度从原来的17.94mm2/s下降到8.279mm2/s,并检测出大量的小相对分子质量化合物,相对含量为22.713%;而DIOA呈褐色,酸值高达12.597mg/g,比原样增加了114倍,黏度降低22.3%。分析可知,PAO黏度严重衰减主要是由高温裂解引起的;而DIOA中的酮、醚、醇、酸等生色物质的生成是导致颜色加深和酸值增大的主要因素。

Autoclave device was used to simulate the high temperature working environment of poly-al- pha-olefins （PAO） and diisooctyl adipate （DIOA） aviation lubricating basic oils, both of whose structures were analyzed by GC/MS, comparative with their samples under 170 ℃, 200 ℃ and 300 ℃. At 300℃, PAO oils showed only pale yellow with its acid value being just 0. 493 mg KOH/g, and its kinematic viscosity decreased from 17.94 mm2/s to 8. 279 mm2/s, detected by addition of a large number of small molecular weight compounds with relative content about 22. 713%. However, DIOA re- presented brown with its acid value being up to 12. 597 mg KOH/g, 114 times higher than the original oils, but its viscosity decreased by 22.3%. Above all, the results showed that high temperature pyrolysis was the main reason which leaded kinematic viscosity of PAO to decline. While in DIOA, some compounds including chromophore groups, such as ketones, ethers, alcohols and acids, were the main factors contributing to deepen the color and increase the acid value.