基于聚-α烯烃油的锂基润滑脂流变性

摘要

为系统研究锂基润滑脂的流变性能，以12-羟基硬脂酸锂皂为稠化剂和聚-α烯烃（PAO）油为基础油制备了锂基润滑脂。考察了稠化剂含量、基础油黏度和温度对锂基润滑脂的触变性、储存模量、损耗模量、表观黏度和应变幅度等流变参数的影响，并对其影响机理进行了探讨。实验表明：锂基润滑脂是屈服性假塑性流体，在很小应变范围内以可恢复的弹性变形为主导，达到其屈服应力后，具有明显的剪切变稀现象；达到其流动点后，表现出黏性流体性质。%In order to study the rheological properties of lithium base grease in a systematic way, lithium lubricating grease is prepared with 12-hydroxy stearic acid lithium soap as the thickener and poly-αolefins(PAO)synthetic oil as base oil. The influ-ence factors such as the content of the thickener, base oil viscosity and temperature on the rheological parameters concerning thixot-ropy, storage modulus, loss modulus, apparent viscosity and strain amplitude are studied and the mechanism is also discussed. Ex-perimental results show that the lithium lubricating grease is yield pseudoplastic fluid, which is highly elastic and can restore elastic deformation at very small strain range, has obvious shear thinning phenomenon after reaching the yield stress, and is highly viscous when it reached its yield point.