Study On Synthesis And Polymerization Process Of 4,8-Diamino-1,5-Naphthalenediol

High performance fiber is indispensable to our defense industry construction and national economic development strategic new materials.It has important applications in various fields such as defense military industry and high-tech industry.However,most of these materials have the disadvantage of poor ultraviolet aging resistance.Therefore,in view of the ultraviolet aging resistance of high-performance fiber,4,8-diamino-1,5-naphthalenediol hydrochloride(DAND ·2HCl)was used as a polymerization monomer to prepare aromatic heterocyclic polymer materials with excellent ultraviolet aging resistance.First of all,with 1,5-naphthenediol as raw material,using fuming nitric acid-concentrated sulfuric acid system and the concentrated nitric acid-concentrated sulfuric acid system two methods of nitrification explores the preparation technology of the intermediate 4,8-dinitro-1,5-naphthenediol(DNND),through the structure characterization testing found that by fuming nitric acid-concentrated sulfuric acid system mainly obtained polynitro compounds 2,4,6,8-tetronitro-1,5-naphthenediol,and the nitrification reaction of concentrated nitric acid and concentrated sulfuric acid system resulted in the target intermediate DNND,and the high performance liquid chromatography shows that its purity as high as 99.5%,The factors affecting the yield of nitrification reaction were analyzed and discussed by the single-factor experiment and the 4-factor and 3-level orthogonal experiment,and the optimal process conditions were determined.Secondly,the catalytic transfer hydrogenation method of ammonium formate system and stannous chloride-hydrochloric acid method were used to investigate the preparation of DAND · 2HCl by reduction of intermediates.It was found that the yield of the products obtained by these two methods was high,reaching about 89%.The high performance liquid chromatography showed that the purity of the product was 93% in ammonium formate system and 85% in stannous chloride-hydrochloric acid method.The results of NMR and FT-IR characterization showed that the structure of the product obtained by stannic chloride-hydrochloric acid method was consistent with the structure of the target compound DAND · 2HCl.The single factor experiment and 4 factor 3 orthogonal experiment were used for the two reduction systems to study the factors affecting the yield of reduction reaction.Finally,the preparation of new aromatic heterocyclic polymer was studied by solution polymerization,and the self-made DAND·2HCl combined with p-benzoyl chloride(TPC)was used for polycondensation.At the same time,the reactivity of DAND · 2HCl in the polycondensation reaction was investigated,the influence oftemperature and time on the polymerization process was explored,and the programmed heating steps of the reaction during the polymerization process were summarized.The existence of amino group,benzene and oxazine rings in the structure of polycondensation products was verified by FT-IR.