The Synthesis And Antioxidant Performance Study Of Amine Fuel Antioxidants

Fuel antioxidant is an addictive which can efficiently improve the antioxidation performance of fuel when it is in storage or in use.Amine antioxidants are one of the most commonly used antioxidants.That is because amine antioxidants have better durability,thermostability and antioxidation performance than phenol antioxidants,thus they can be used in higher temperatures.p-Phenylenediamine derivatives are excellent fuel antioxidants,especially when used in gasoline with high olefin contents.However,this type of antioxidants is usually produced by catalytic hydrogenation.The present technology requires a high temperature and a high hydrogen pressure,which could lead to potential danger,high energy consumption and low efficiency,and the equipment needs to be specially made.In addition,the technology is difficult to handle due to the easy sublimation of p-phenylenediamine.Therefore,the product in China is mainly imports and the price is high.It is desirable to improve or even develop a new technology for the preparation of p-phenylenediamine derivative antioxidants.It has been proved that there is synergetic effect when an amine antioxidant is used in combination with a hindered phenol antioxidant.And such kind of synergism has been widely applied in today’s marketplace.Recently,the combination of amine and phenolic moieties in one molecular has attracted wide attention.Herein,we developed a synthesis method through which p-phenylenediamine derivative antioxidants can be efficiently prepared in very mild conditions.Their thermostability and antioxidation performance was investigated.Meanwhile,two phenol-amine type antioxidants were prepared and their structure and property were studied.This thesis was carried out the following two studies:1.New synthetic methods for 180 and 182 antioxidants.In this study,both 180 and 182 were prepared in very mild conditions with p-phenylenediamine and butanone as starting materials,acetic acid as a promoter and Na(OAc)3BH as a reducing agent.Their purity and structure were characterized by HPLC,FT-IR and NMR.Their thermalstability and antioxidation performance were studied by thermal gravimetric analyzer(TGA),pressurized differential scanning calorimeter(PDSC)and rotation bomb oxidation tester(RBOT).The results indicated that 180 and 182 synthesized hrein has high purity(up to 98%),good thermal stability and excellent antioxidation activity.In addition,the compatibility of 180 with two hindered phenol antioxidants was investigated.2.In this study,181 has been successfully prepared in mild conditions very efficiently,and we have studied the reaction systematically.In addition,a new phenol-amine oil antioxidant 2,6-di-tert-butyl-4-((phenylamino)methyl)phenol was designed and successfully synthesized.The purity and structure of the new compound were characterized by HPLC,FT-IR and NMR.The thermalstability and antioxidant performance were studied by thermal gravimetric analyzer(TGA),pressurized differential scanning calorimeter(PDSC)and rotation bomb oxidation tester(RBOT).The results indicated that the introduction of phenyl group and the reservation of hydrogen atom linked to nitrogen atom could improve the thermostability and antioxidation activity.