环烷酸铅和烷基水杨酸铅的微波原位合成及其摩擦学性能

在液体石蜡中采用微波技术原位合成了油溶性环烷酸铅(LN)和十二烷基水杨酸铅(LAS).在高速低负荷(r=1500±10 rpm、 P=196～392 N)和低速高负荷(r=300±10 rpm、 P=800 N)两种条件下,用四球摩擦磨损试验对LN、 LAS和对应的羧酸进行了摩擦学性能评价,用往复式摩擦试验机考察了LN和LAS抗磨减摩性能.结果表明: LN具有良好的抗磨减摩性能和中等的极压性能,且各项摩擦学性能指标均好于LAS.为弄清其作用机理,从分子结构分析了产生摩擦学性能差异的原因,并用SEM及XPS研究了磨斑表面.结果发现: 摩擦过程中, LN和LAS都能在摩擦副表面形成吸附膜且部分吸附膜发生摩擦化学反应产生了铅氧化物转化膜,但所形成的吸附膜和转化膜厚度不同.

In-situ Synthesis of Lead Naphthenate andLead Alkylsalicylate as by Microwave-assisted Technique and Tribological Behaviors

Oil soluble lead naphthenate(LN) and lead alkylsalicylate(LAS) were in-situ synthesized by microwave assisted-technique in liquid paraffin. The tribological properties of LN , LAS and corresponding carboxylic acid were evaluated with four-ball tribo-tester under the condition of high speed (r=1500±10rpm) low load (P=196~392N) and low speed (r=300±10rpm)high load(P=800N). The anti-wear and friction-reducing of LN and LAS as additives were also evaluated with reciprocation tribo-tester. The results indicated that LN additive exhibited good anti-wear property, good friction-reducing efficiency and middling extreme pressure property, and all tribological properties of LN as additive was better than LAS. The reason producing the performance difference of tribological behaviors was analyzed for revealing tribological mechanism, and wear scar surface was characterized with photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Analytical results showed that LN and LAS could formed adsorbing film on steel-steel friction pair and part of film transformed oxidic film protecting the rubbing surfaces from wear by means of tribochemical reaction, but the thickness of films was different.