Study On The Synthesis Of Brominated Flame Retardants And Coating Technology

Hexabromocyclododecane in brominated flame retardants is an excellent flame retardant.The thesis focuses on the synthesis of brominated flame retardants-hexabromocyclododecaneand coating technology, and mainly includes three parts: the synthesis of HBCD in thealcohol-chlorohydrocarbon solvent system, the synthesis of HBCD in the solution of dioxaneand water, and the study of encapsulating of HBCD.In the solvent system of alcohol-chlorohydrocarbon, the effect of solvent system, theratio of solvents, the mole ratio of substance, the way of dropwise addition, dropwise additiontime on the synthesis of HBCD was studied through a single factor experiment. The optimalsynthesis conditions were as follows: the solvent system was Chloroform-isobutyl alcohol,the mass ratio of m (Chloroform):m(isobutyl alcohol) was1:1, the mole ratio ofn(bromine):n(CDT) was3.5:1, the dropwise addition way of bromine and CDT wassimultaneously at the same time, dropwise addition time was8hours. The yield of productcan reach87.9%, and the melting point can reach185℃. The product analysized by means ofhigh performance liquid chromatography, the purity of product can reach92.5%, α, β and γisomer ratio were9.82%,3.85%and86.33%respectively. The structure of product wasconformed by infrared spectrum.In the solution of dioxane and water, the effect of solvent system, the ratio of solvents,the temperature of dropwise addition, the way of dropwise addition, reaction time on thesynthesis of HBCD was studied through single factor experiment. The optimal synthesisconditions were as follows: the solvent system was dioxane–48%hydrobromic acid, themass ratio of m(dioxane):m(48%hydrobromic acid) was6:3, the temperature of dropwiseaddition was15℃, the dropwise addition way of5g CDT and15g bromine wassimultaneously at the same time after the addition of1g bromine, reaction time was3hours.The yield of product can reach92.7%, and the melting point can reach180℃. The product analysized by means of high performance liquid chromatography, the purity of product canreach97.2%, α, β and γ isomer ratio were15.3%,8.7%and76.0%respectively.In the study of encapsulating of HBCD, the optimal synthesis conditions were as followsthrough single factor experiment: in the process of synthesis, the mole ratio ofn(formaldehyde):n(melamine) was2.0:1, pH was8.5, and reaction temperature was80℃, inthe process of encapsulation, the mass ratio of wall material and core was1.5:10, pH was6,and reaction temperature was65℃. Solid content of prepolymer was23.42%, and theprepolymer was still clear after ten days. Thermally decomposed temperature of encapsulatedHBCD was232℃. The product was conformed by infrared spectrum and scanning electronmicroscope.