Green Synthesis Of Phosphorus And Brominated Flame Retardants And Application Research Of Brominated Flame Retardants

With the development of society,the demand for fine chemicals is increasing with inevitably causing a series of environmental problems.Many mature production technologies of fine chemical products become difficult to meet the requirement of social development due to their high energy consumption and emissions.Flame retardant,known as the "invisible protector of human",is also undergoing an upgrade from the traditional method to the green synthesis method.Accordingly,researchers have develop a number of more safe and convenient synthesis methods to solve the problems of toxic and harnful solvents and catalysts in traditional methods.of which,the reaction in aqueous phase and the solvent free reaction of solid and liquid have attracted much attention.The green synthesis routes of three important flame retardants(2,2',6,6'-tetrabromobisphenol A diallyl ether(TBBPA-DAE),tetrabromobisphenol A bis(dibromopropyl ether)(BDDP)and triethyl phosphate(TEP))were explored by the application of "green chemistry,concept.(1)In this study,the addition reaction of water insoluble olefins and bromide in aqueous phase was successfully achieved without assistance of catalysts.Critical factors such as types of additives,reaction temperature,time and material ratio were investigated to obtain the optimal conditions:n(TBBPA-DAE):n(Br2)=1:2.2 react at 55oC for 5.5 h with addition of 0.018 mol/L sodium dodecyl sulfate for dispersion of raw materials.White BDDP powder was successfully prepared by this reaction with a yieldof 93.6%,and a purity of 91.7%.This method greatly simplifies the postreatment process comparing to original process with distillation and crystallization,and avoid the use of toxic and harmful organic solvents of chloralkane,embodies the concept of green and environmental protection.(2)The intermediates was successfully separated from TBBPA-DAE reaction system for investigating the mechanism.The reaction conditions were optimized,and the filtrate was recycled for reaction to decrease the usage of water.After five times recycles,the resulting product is still white powder with a yield of 98%,the resulting product crystal and particle size distribution is much better than the current domestic markeTab.products.On this basis,scale-up experiment of TBBPA-DAE and design of industrial production route were completed.Pilot scale experiment was also successfully performed in a 2000L reactor.(3)In this research,the reaction of phosphorus oxychloride and sodium ethoxide at low temperature for synthesis of TEP was explored.Colorless and transparent TEP products was obtained from the reaction with a yield over 90%,and an acid value less than 0.05 mgKOH.g-1.Compared to the original synthesis method,this method significantly decreased the reaction time,avoided the waste of organic solvents,and improved the acidity of original production process at the same time.(4)This chapter studied the mechanical property and flame-resistant effect of the building exterior wall thermal insulation material of PS with addition of BDDP instead of adding HBCD.The effects of BDDP,Sb2O3,modified Mg(OH)2 and its compound system on the flame resistant effect and mechanical properties of PS were studied.The experimental results show that when the BDDP/Sb2O3/modified Mg(OH)2 compounded system added up to 29%,PS flame retardant reached V-0 level.Meanwhile,other mechanical properties were all increased,except 3%decrease of elongation.