硬脂酸改性层状硅酸钠的摩擦学性能研究

 以硬脂酸作为改性剂，采用超声改性法对层状硅酸钠进行改性，制备了改性层状硅酸钠（改性层硅）用作润滑油添加剂。用沉降体积、光学显微镜、红外光谱和X射线衍射仪等测试手段对改性层硅进行表征，并在摩擦磨损试验机上考察其摩擦学性能，用扫描电子显微镜观察磨痕表面形貌，探讨改性层硅的减摩抗磨机理。分散性试验结果表明，改性层硅在500SN基础油中具有良好的分散稳定性；红外光谱结果表明，改性层硅表面存在有机官能团；X射线衍射结果表明，改性层硅晶体结构与改性前相比没有改变。当改性层硅质量分数为0.6%时，油样具有好的抗磨性能，磨斑直径减小11.5％；当改性层硅质量分数为0.8%时，油样具有好的减摩性能，摩擦系数减小29.7％。

RESEARCH ON THE TRIBOLOGICAL PROPERTIES OF STEARIC ACID MODIFIED LAYERED SODIUM SILICATE

Using stearic acid as modifier, layered sodium silicate (LSS) was modified by ultrasonic treatment to serve as additive of lubricating oil. Modified layered sodium silicate (MLSS) was characterized by sedimentation volume analysis, optical microscope, FT-IR and XRD. The tribological properties of LSS and MLSS as additive in 500SN base oil were investigated with friction and wear testers. The morphologies of worn steel surfaces lubricated with various lubricant systems were observed by a scanning electron microscope. The mechanism of friction reduction and anti-wear function of MLSS additive were also discussed. Dispersion test results showed that MLSS well dispersed in 500SN base oil stably. FT-IR spectra observed that organic functional groups existed on MLSS surface. XRD results indicated that the crystal structure of MLSS was the same as prior to modification. As compared with LSS additive, oil sample having a MLSS dosage of 0.6% exhibited the best anti-wear property, the wear scar diameter decreased by 11.5％; oil sample having a MLSS dosage of 0.8% possessed the best friction reducing performance, the friction coefficient decreased by 29.7％.