Synthesis And Properties Of Lubricating Oil Additives Containing Nitrogen And Thio Heterocyclic Esters

Friction and wear will greatly reduce the reliability,durability and energy utilizat ion of mechanical equipment.Adding lubricating oil containing extreme pressure/anti-wear additives can alleviate this phenomenon.The use of chlorine,phosphorus and me tal antiwear/extreme pressure agents is decreasing due to environmental reasons.Man y future lubricants are more environmentally friendly,ashless and anti-wear agents gi ven the same performance and cost.As the demand for lubricants increases,new pot ential markets include biodegradable lubricants,advanced vehicle lubricants and space technology lubricants.Moreover,with the technological updates in traditional markets such as engine oil,ship,aviation,gear and metal processing fluid,and other industr ial lubricants,it is difficult to meet the requirements of lubricant additives on the ma rket at present.Therefore,it is of great significance to develop high-quality and high-grade lubricant additives.Twelve new lubricating oil additives containing nitrogen an d sulfur heterocyclic ester derivatives were synthesized in this paper.Their molecular structures were characterized by ~1H NMR and MALDI-TOF-MS.The oil solubility a nd corrosion resistance of additives in vegetable oil(VO)were studied by qualitative analysis.The thermal stability of the molecule was studied by thermogravimetric ana lyzer.The tribological properties were analyzed and discussed by measuring the maxi mum non-sticking bite load,sintering load,wear spot diameter and friction coefficient.The main research contents are as follows:(1)Three kinds of lubricating oil additives(1a~1c)of benzotriazole arginine pro pyl acetate derivatives with different structures were designed and synthesized.The re sults show that the corrosion grade of 1a~1c copper sheet is 1a,and they exhibit ex cellent oil solubility and thermal stability.The thermal decomposition temperatures are all at 200 C.The maximum cardless bite load P_B value of 1.0%(mass fraction,the same below)1c oil sample is 1.7 times that of VO,the sintering load P_D value is1.3 times that of VO,and the wear spot diameter is reduced by 50.7%compared wi th VO.The friction coefficient is reduced by 59.1%compared with VO.(2)Three kinds of 2-mercaptobenzothiazole-arginine-propyl acetate derivative lubri cating oil additives(2a~2c)with different structures were designed and synthesized.T he results show that the corrosion grade of 2a~2c copper sheet is 1a,and they exhib it excellent oil solubility and thermal stability.The thermal decomposition temperature s are all at 205 C.The maximum P_B value of 1.0%2c oil sample is 1.8 times of VO,the P_D value of sintering load is 1.6 times of VO,the diameter of wear spot is45.9%less than VO,and the friction coefficient is 50.8%less than VO.(3)Three kinds of lubricating oil additives(3a~3c)with different structures 2-me rcaptopyrimidine-arginine-propyl acetate derivatives were designed and synthesized.Th e results show that the corrosion grade of 3a~3c copper sheet is 1a,and they exhibit excellent oil solubility and thermal stability.The thermal decomposition temperatures are all at 190 C.The maximum non-sticking bite load P_B value of 1.0%3c oil sa mple is 83.3%higher than VO,the sintering load P_D value is 25.0%higher than V O,the wear spot diameter is 45.1%lower than VO,and the friction coefficient is 41.8%lower than VO.(4)Three kinds of lubricating oil additives(4a~4c)of 2-mercaptobenzoxazole-arg inine-propyl acetate derivatives with different structures were designed and synthesized.The results show that the corrosion grade of 4a~4c copper sheet is 1a,and they ex hibit excellent oil solubility and thermal stability.The thermal decomposition temperat ures are all at 200 C.The maximum non-sticking bite load P_B value of 1.0%4c oil sample is 83.3%higher than VO,the sintering load P_D value is 25.0%higher than VO,the wear spot diameter is 43.1%lower than VO,and the friction coefficient is36.1%lower than VO.(5)Four series of 12 compounds synthesized have good thermal stability,corrosi on resistance and oil solubility.Four series of additives all showed excellent extreme pressure performance.Among them,P_B of 2c containing 2-Mercaptobenzothiazole in molecular structure was much higher than vegetable oil and ZDDP,which was the best extreme pressure agent.1c containing benzotriazole in molecular structure has hi gher antiwear and antifriction effect than vegetable oil and ZDDP,and was the best antiwear and antifriction agent.