Study On The Synthesis And Application Of Flame Retardant Tetrabromobisphenol-A

Tetrabomobisphenol-A is an excellent flame retardant in brominated flame retardants,it's a kind of high efficient flame retardant which can be used as reaction type or additive type and widely used in plastics,rubber,textile,fiber and paper industry because it can't produce carcinogens in the combustion process and cost-effective.However,it still faces the bottleneck of low reaction conversion rate and product purity,so researchers are in urgent need of technical transformation.In this paper,tetrabromobisphenol-A was synthesized from bisphenol-A,bromine,hydrogen peroxide by differentiated multi-pipe synchronous drip technology with chlorobenzene as solvent and its application was also studied.In the first part of this thesis,TBBA was synthesized from bisphenol-A,bromine,hydrogen peroxide by differentiated multi-pipe synchronous drip technology,the key factors of TBBA were investigated such as material ratio,reaction temperature and bromination temperature and its structure,content and thermogravimetric temperature were characterized by IR,HPLC and TGA respectively.The optimum preparation conditions were explored by single factor experiments and orthogonal experiments:the molar ratio of the reactants n?BPA?:n?Br₂?:n?H₂O₂?was 1:2.1:2.2,the reaction temperature was 22?and the bromination temperature was 80?.In addition,other solvents were also used to synthesize TBBA and the effects on yield,chroma,purity and solvent recycling were discussed in detail.The results showed that when dichloromethane and trichloromethane were used as solvents,the reaction temperature was 25?±1?,the chroma and purity were better than those of chlorobenzene method, but the amount of solvent was twice of chlorobenzene method.Under the optimum conditions,the purity of TBBA was not less than 99%,and the temperature was 249?at the loss of 1%through testing and characterization.In the second part,brominated epoxy resin was synthesized from TBBA and epichlorohydrin by the method of etherification and cyclization,the important factors of intermediates of brominated epoxy resin were studied such as the dosage and concentration of alkali,cyclization reaction time and type of catalyst and phase transfer solvent.Its structure,content,molecular weight and thermogravimetric temperature were characterized by IR,HPLC,GPC,and TGA respectively.The optimum preparation conditions which explored by single factor experiments were as follows:the dosage of alkali was 60%based on bisphenol A and the concentration was 35%,tetramethyl ammonium chloride was used as catalyst and toluene was used as phase transfer solvent,cyclization reaction time was 4h.Under the optimum conditions,the purity of intermediates was not less than 94%,the molecular weight was not less than 20000,and the thermal analysis showed that the temperature was 363?at the loss of 1%.In the third part,ethoxylated tetrabromo bisphenol“A”diacrylate was synthesized from TBBA and ethyl acrylate by the method of etherification.The effects of key factors such as material ratio,solvent type,reaction temperature and reaction time on yield and purity were investigated,and the content was characterized by HPLC.The optimal conditions which explored by single factor experiments were as as follows:the molar ratio of the reactants n?TBBA?:n?2-chloroethyl acrylate?was 1:2.4,reaction temperature was 55?,reaction time was 5-6h and DMF was used as solvent.Under the optimal conditions,the yield was not less than 90%and the purity was not less than 97.2%through testing and characterization.However,other parameters of the product are still being studied.In the fourth part of this paper,to the need of production safety,the effect of heat on the bromination oxidation and polymerization reaction was investigated in detail,and the calorimetry monitoring of the raw materials and reaction process was studied.The results showed that both the bromination oxidation reaction and the polymerization reaction were exothermic seriously.It will easily lead to production accidents while the maximum accumulative temperature rising,if the cooling system was failure.Therefore it has to make sure that the heat must be removed in time in the actual production process.In the last part of this paper,the pollution production link was analyzed from the perspective of environmental protection,according to the current production technology status.The indexes of phenols,hydrogen bromide,VOCs and toluene in waste gas,chemical oxygen demand and chloride in waste water were tracked and determined.The results showed that the average contents of phenols,hydrogen bromide,VOCs and toluene in the treated gas were respectively 0.5mg/m³?3.6mg/m³?11mg/m³?1.4mg/m³,These indicators conformed to emission standards.The average contents of chemical oxygen demand and chloride in waste water were respectively 79mg/L?19mg/L.The composition of the three wastes was stable,and the pollution index fluctuated little after treatment.All indicators ultimately complied with all criteria of the standard and the wastes from the production reached the disposal standard.These indicators met the acceptance criteria of the company.All kinds of solid wastes were entrusted to a company with hazardous waste treatment qualification for harmless disposal according to relevant regulations.