| High molecular weight bromated epoxy resins is a sort of the novel bromine-containing flame retardants which has excellent flame retardant efficiency and can not easily move from polymer materials. It has been researched and developed abroad recently. Some flame retardant polymer materials added the high molecular weight bromated epoxy resins as flame-retardant additive have been studied that such flame retardant agent has a combination of good fire retardant efficiency, UV stability, excellent mechanical properties, thermal stability and nonblooming ,which is the ideal substitute of decabromodiphenyl oxide. The real domestic industrialization for them has not been realized. Currently, there is only Dead Sea Bromine Group in Israel selling its products of these kinds of flame-retardants in our country. Therefore, the research and development of them is very important.The present work is dedicated to the research and development of new methods, which prepared tetrabromobisphenol A and high molecular weight bromated epoxy resins. The applied research of the high molecular weight bromated epoxy resins as flame retardant was studied at the same time.One subject of the present work relates to a green chemistry synthesis of tetrabromobisphenol A wherein the combination of sodium bromide and sodium bromated as brominating agent which completely replaces conventional liquid bromine. This new methods can shun corrosiveness of liquid bromine or gas hydrogen bromide released during bromating reaction to the equipments and eliminate harmfulness to the operating worker and environment.Detailed research is concerned with the conditions such as solvents, reaction time, reaction temperature, phase transfer catalyst and the ratio of raw materials having influence to the product's quality and yield. It is also concerned with the organic solvent being recycled and having no influence to the quality and yield of the production. The melting point ranged from 180.0 to 182.1℃, and bromine-content of production is over 58.0% are same as to the production prepared by literature.One-step synthesis of the high molecular weight bromated epoxy resins for flame retardants is studied with tetrabromobisphenol A and epichlorohydrin as raw materials in mixed solvent comprising 1,4-dioxan and water.The findings of present work show that organic/water ratio,alkali metal alkali, phase transfer catalyst, reaction time, reaction temperature, all of them have influence to the molecular weight and yield of the production. In the presence of the phase transfer catalysts such as tetramethylammonium bromide, tetraethylammonium bromide or polyethylene glycol(MW 400 and 6,000),lithium hydroxide is the best alkali among lithium hydroxide ,sodium hydroxide and potassium hydroxide. In the presence of alkali metal hydroxide,the phase transfer catalyzed composition comprising of tetramethylammonium bromide and polyethylene glycol(MW 6,000) is more effective than any other phase transfer catalyzed systems made up of only one phase transfer catalyst such as tetrametylammonium bromide, tetraethylammonium bromide and polyethylene glycol(MW 400 and 6,000).Under the optimized conditions,three sort of products(MW 25×104,4.5×104 and 6.1×104) were prepared through varied conditions of the raw materials ratio and the reaction time. Bromine content of them is all over above 52.0%. All of their thermal decomposition temperature is over 310℃. The structures of finished products which have epoxy group at both end of their molecular chain proved by the infrared spectrum.Flame retardant properties and mechanical properties of ABS which was incorporated into different molecular weight bromated epoxy resins flame retardant agent were evaluated. Our studies investigated the comprehensive mechanical properties of ABS added bromated epoxy resin with different molecular weight are almost as good as that ABS added decabromodiphenyl oxide .But most preferable is 61 thousand among the different molecular weight products. The bromated epoxy resin w...
|
PDF Full Text Request