Research On Surface Modification And Controll Morphology Of Mg（OH）₂Flame Retardant

Magnesium hydroxide is a inorganic additive flame retardant, smokesuppression and fire-retardant performance is outstanding, while it also has a strongsurface polarity, hydrophilic, when added directly to the polymer dispersionresistance and poor compatibility, affect the processing properties of the composite.In order to improve the compatibility and dispersibility of magnesium hydroxidewith the polymer, changing its surface properties with "hydrophilic and oleophobic",it must be surface-modified for magnesium hydroxide. Special morphologyespecially magnesium hydroxide flakes and whiskers, when added to the polymermaterial, in addition to playing the role of flame and smoke suppression，and alsobecause of its special topography play other enhancements.In this paper, magnesium hydroxide on wet surface modification by compoundmodifier. Single factor experiments were explored by magnesium hydroxide duringthe surface modification factor (stirring rate, time, temperature, amount of modifier,the modifier type, the ratio modifier, the concentration of the magnesium hydroxideslurry, feeding method, aging time, the number of washing) on the modificationeffect. Obtained the optimum conditions by orthogonal experimental, the followingconclusions: the optimum conditions of Z1composite modifier is: the amount ofsurface modifier is9%Oil sodium/sodium stearate/polyethylene glycol6000=2:2:1ratio of ingredients, modified temperature is60℃, the modified time is100min. The results showed the magnesium hydroxide modified in the gooddispersibility of the paraffin wax, infrared spectroscopy showed a surface modifieradsorbed molecules on the surface of magnesium hydroxide, SEM images showaggregates of magnesium hydroxide modified after the case has been significantlyimproved, drops in with a modified magnesium hydroxide paved TLC plate showedobvious "lotus effect."Meanwhile, the paper also research on controlling magnesium hydroxidecrystal morphology. Supercritical CO2fluid equipment preparation of basic magnesium carbonate whisker precursors under hydrothermal conditions intomagnesium hydroxide whisker through concludes: In the supercritical state (T>31.1℃, P>7.38MPa), time6h, polyethylene glycol1000as grain under control agents,water as a solvent to produce a diameter of1~5μm, long50~150μm of basicmagnesium carbonate whisker by hydrothermal conversion later became a diameterof0.2to0.6μm, length2~8μm magnesium hydroxide whisker; prepared bymicrowave hydrothermal synthesis of hexagonal flake magnesium hydroxide, theexperiment concluded: In the microwave power400w, temperature of180℃, time80min, the generation of regular shape hexagonal flake magnesium hydroxide.