Study On Synthesis Of Modified Zinc Borate For Polymer's Flame Retardant

Inorganic fire-retardant which has no halogen showed excellent heat-resistance property. The advantages of inorganic flame-retardant were no emission noxious and causticity gas, no-toxical and no second pollution when burning. As a sort of inorganic flame-retardants, Zinc Borate was one of the excellent flame-retardants in plastic, rubbers, chemical architecture materials and other organic macromolecule compounds.New technology, such as miniaturization and surface modification, were adopted to improve flame retardation of inorganic flame-retardant.The paper introduce 2 methods to prepare ZB-2335 through using zinc oxide-boracic acid and zinc sulfate-borax-boracis acid. The significant factors which affects the reaction production were ascertained by orthogonal experiment: proportion of materials, liquid-solid ratio, reaction temperature, reaction time. Compared to the current route, it was showed that maintaining the concentration of boracic acid could reduce a half reaction timeOne-step which was surface modification of zinc borate in its preparation process was adopted to researched the effect of the sort, additive dosage and the size of alkyl chain of surfactants on the properties of modified ZB-2335. It was found that the properties of modified ZB-2335 wrer improved with the increas of the dosage of surfactants and finally reached a costant when the surfactants contiously increased. In addition, the effect of the size of alkyl chain of surfactants were investigated. It was showed that the properties of modified ZB-2335 improved along with the increase of alkyl.Based on the experimental results, the optimum conditions to produce ZB-2335 were as follow:n(Na2B4O7·10H2O):n(ZnSO4·7H2O):n(H3BO3)=1:1:2, n(ZnSO4·7H2O):n(H2O)=1:45, reaction temperature=90℃, reaction time=5 h, w(sodium stearate)= 1.5% which added after 3 h when reaction started.Finally, the prepared ZB-2335 was used to fill into plastic to research the changes of mechanical and burning property of plastic. The results showed that the modified ZB's had less affect on the mechanical property of plastic than the black samples. Moreover, the samples which added Sb2O3 and ZB existed more flame-retardant effect than the contract samples.