A Study on Tribodegradation of Lubricating Oils under Rolling friction and Friction-polymer formation

作为研究的第一步，对实验方法和程序进行了研究。研究的主要目的是找到一种在摩擦试验中只使用少量的试验液而不造成严重损害的实验方法，并检测降解后的油中含有的少量化合物。以滚动四球摩擦试验机为摩擦装置，采用傅立叶变换红外光谱(FT-IR)和高效液相色谱-凝胶渗透色谱(HPLC-GPC)对降解后的润滑油进行了分析。摩擦实验的实验条件为：轴向载荷294N和98N，转速2500rpm，温度：室温。以高纯度加氢精制石蜡矿物油为试验油。在294N下进行摩擦实验后，油变得油腻，油样颜色变棕色。FT-IR分析表明，降解油中含有&gt；C=O、-OH、-CoO^-、Fe_2O_3。凝胶渗透色谱(GPC)分析表明，尽管用0.45微米的膜过滤器过滤，降解油中仍含有大量的物质。证实了这种大颗粒物质不是在油的静态氧化过程中形成的。结果表明，降解油中含有吸附了-gt；C=O、-CoO-基团的氧化产物的极细小的磨粒。这使得降解后的油变得油腻。在98N以下，油不会变得油腻和褐色，但油中还存在一些特征化学基团，如-COO^-和Fe_2O_3。

Experimental methods and procedures were studied as a first step of the research. The major objectives of the study were to find the experimental method which anable to use only a small amout of test fluids without sever damages during friction tests and to detect the small amout of compounds which were contained in the degraded oils. Rolling-four-ball tribometer was selected as friction apparatus and FT-IR and HPLC-GPC were selected for the analyzes of the degraded oils.The experimental condition of friction experiments were ; axial load : 294N and 98N,rotating speed : 2500rpm, temperature : room temp. Highly purified hydrorefined paraffinic mineral oil was used as the test oil. After the friction experiment under 294N,the oil became greasy and color of the sample oil changed to brownish. Presence of >C=O,-OH,-COO^-, Fe_2O_3 were found in the degraded oil by FT-IR.From the GPC,very large substance was detected in the degraded oil, in spite of the filtration with memblane filter having a pore size of 0.45mum. It was confirmed that such a large size substance was not formed in the static oxydation of the oil. It can be concluded that very fine wear particles on the surface of which oxydation products having >C=O,-COO- groups were adsorbed, were contained in the degraded oil. This made the degraded oil greasy. Under the 98N,the oil did not change to greasy and brownish but some characteristic chemical groups like -COO^- and Fe_2O_3 were also found in the oil.