Studies On The Structures And Properties Of Polyurea Grease Based Pao Synthesized By Oligomerization Of α-olefin

With the rapid development of modern industry,the requirements for grease are becoming more and more demanding in various fields,and the high quality and multi-effect grease is the development direction.Polyurea grease is known as"a new generation of efficient grease since it has the advantages of complex lithium grease,complex calcium sulfonate grease and complex aluminum grease.It is also one of the environment-friendly greases whithout heavy metals and other additives to pollut environment.We synthesized high-performance base oil for polyurea grease,and studied the relationship between thickener and structure/performance of polyurea grease,then explored the mechanism to reduce noise with polyurea grease.The main contents of this paper are as follows:1. We invested the oligomerization of 1-decene viaCl₂as catalyst.The optimum reaction conditions was found:1-decene of 40 ml,toluene of 10 ml,Cl₂of 10mmol,Al/Zr molar ratio of 300,reaction at 60°C for 2 h with the catalytic activity is 1160 kg·（mol Zr）^-1·h^-1and the yield was 77.3%.The oligomer has good performances,such as,kinematic viscosity of 66.56 mm²·s^-1 at 100°C,Mn of 337,pour point for-42°C.TheCl₂showed higher catalytic activity comparing with（Me₄Cp）₂Zr Cl₂.2. We used Diphenyl-methane-diisocyanate（MDI）and two kinds of amine（aniline,octyl amine,cyclohexylamine,octadecylamine or ethylenediamine,etc.）to prepare thicker for polyurea grease with polyolefins（PAO）oil as base oil.The production process（raw materials,feeding methods,temperature）and post-treatment process（such as cooling mode,shear dispersion）process conditions were invested.The relationship between the structure and grease performance of polyurea grease was studied.The polyurea grease prepared with two kinds of blended amine and MDI showed the best performance,such as drop point of 282℃,consistency of 240 p/0.1mm and the apparent viscosity of 1.82 Pa.s.The higher thermal stability originates from the intertwining of fibers.The polyurea grease has better performance such as higher dropping point,better colloidal stability and better stability,which thickener prepared with the mole ratio of n（octadecylamine）:n（cyclohexylamine）=5:5.3,In order to explore the noise reduction mechanism of polyurea grease,we studied the relationship between refining temperature and properties of the polyurea grease such as fiber structure,friction properties and rheological properties and so on,which grease was prepared with blended amines and MDI as thickener,PAO as base oil.It is found that with the increase of the refining temperature,the polyurea fibers change from disorder to ordered arrangement,and the polyurea molecules form a stable three-dimensional space structure through hydrogen bonds,which eventually reduces the noise of the lubricating system.