Study On Optimized Synthesis And Antioxidant Property Of (single?bis) Butyl Diphenylamine

Lubricating oil is widely used and it is likened to the blood of the mechani cal operation,During using,the oil is easily oxidized and deteriorated,then the regular service of mechanical components will be affected,so various antioxidants are needed to slow down the deterioration of lubricating oil and prolong the service life of lubricating oil.As the main antioxidants,alkylated diphenylamine is widely used in the market,and it has great research value.This kind of antioxidant can effectively prevent the oxidation of lubricating oil and greatly improve the quality of oil products,to some extent,it solves the problem of short life of oil.In this paper,a low cost and high yield route for the synthesis of alkylated diphenylamine was designed.Five kinds of single and double alkylated diphenylamine were prepared by C-N coupling reaction with different raw materials.Thenthe reaction conditions were screened and optimized.Finally,oxidation resistance of all the alkylated diphenylamine were tested.Specific studies are as follows:(1)Choose potassium tert-butoxide as catalyst,4-butyl-N-phenylaniline,.(4-secButyl-phenyl)-phenyl-amine,bis-(4-butylphenyl)-amine,(4-Butyl-phenyl)-(4-sec-butyl-p henyl)-amine and bis-(4-sec-butyl-phenyl)-amine were prepared by C-N coupling r-eaction with different raw materials.IR and 1H-NMR were used to characterize the structure of these five kinds of alkylated diphenylamine.They are identified as target products.(2)The route of preparing 4-butyl-N-phenylaniline and bis(4-butylphenyl)amine was selected to investigate the effect on the yield of catalyst dosage,reaction temperature,reaction time and ratio of raw materials.The results show that,when the ratio of aniline and 1-bromo-4-butylbenzene was 1.4,reaction time was 7h,reaction temperature was 85?,the yield of 4-butyl-N-phenylaniline was about 85%;when the ratio of 4-butylaniline and 1-bromo-4-butylbenzene was 1.6,reaction time was 8h,reaction temperature was 100?,the yield of bis(4-butylphenyl)amine was about 76%.The other three kinds of alkylated diphenylamine were prepared by the best synthesis conditions,and the yield of(4-sec-Butyl-phenyl)-phenyl-ami ne was 82%,(4-Butyl-phenyl)-(4-sec-butyl-phenyl)-amine was 75%,bis-(4-sec-butyl-phenyl)-amine was 76%.(4)Oxidation stability of all the alkylated diphenylamine were tested in base oil 1427 by the meas of pressure differential scanning calorimetry(PDSC),it was found that the initial oxidation temperature of mono substituted diphenylamine was increased by 4?~10?,and the initial oxidation temperature of bis substituted diphenylamine was increased by 10?~20?.