Study On The Process Of Hydrogenation Of1,5-dinitronaphthalene

1,5-diaminonaphthalene is an useful chemistry raw material and intermediatewhich is widely used in the material chemistry and biopharmaceutical industry. Oneof the most useful application is to produce1,5-naphthalene(NDI),which is an keyraw material in the synthesis of NDI polyurethane. NDI polyurethane with excellentphysical performance characteristics can used in high temperature, high grease andhigh mechanical wear occasion, which has an extensive application and wideforeground. This article focus on the effects of different catalyst systems on the1,5-dinitronaphthalene hydrogenation to1,5-diaminonaphthalene.In this study, A high performance liquid chromatographic method wasestablished for analysis of1,5-dinitronaphthalene and1,5-diaminonaphthalene. By theoptimization of analysis conditions, each substance can be separated and which has anprecise detection results.Firstly, The reaction condition for hydrogenation of1,5-dinitronaphthalene using5%Pd/C as catalyst was investigated, and we have investigated different reactiontemperature, reaction time and reaction pressure on hydrogenation of1,5-dinitronaphthalene. The optimum conditions were as follows: when the reactiontemperature was80℃, the reaction time was4h and the reaction pressure was0.8MPa, the reaction can get a better effect.1,5-dinitronaphthalene could beconverted completely and the selectivity of1,5-diaminonaphthalene was93.12%.Moreover, the recycle properties of5%Pd/C catalyst for hydrogenation of1,5-dinitronaphthalene was investigated. The results indicated that the activity of5%Pd/C would have a bit decrease with the increase of cycling times. When thecatalyst was reused for10times, the selectivity of1,5-diaminonaphthalene descended4.82%.we have preliminarily investigated the influences of different solvents, differentmetal loading and different supports on hydrogenation of1,5-DNN. The results showthat using aniline as solvent,the reaction can get a better effect. It was found that25%loading of Ni supported on MWCNTs-2catalyst have better catalytic activity onhydrogenation of1,5-dinitronaphthalene.Ni/CNTs catalysts were prepared with different types of carbon nanotubes andcharacterized by N2adsorption-desorption, XRD, BET, SEM and H2chemisorption.The results showed five Ni/CNTs catalysts were mesoporous in carbon nanotubes support.25%Ni/MWCNTs-2catalyst have the best catalytic performance onhydrogenation of1,5-dinitronaphthalene, because on the one hand it have an bettercatalyst structure, on the other hand the active component Ni which load on thesurface of the catalyst have more regular particle size and dispersion.the catalytic performance of25%Ni/MWCNTs-2was investigated onhydrogenation of1,5-dinitronaphthalene. The optimum reaction conditions wereobtained, when the reaction temperature was120℃, the reaction time was5h, thereaction pressure was1.0MPa,1,5-dinitronaphthalene could be convertedcompletely and the selectivity of1,5-diaminonaphthalene was90.4%.