Synthesis Of Magnesium Hydroxide As Flame Retardant And Application In Polypropylene

At present, the society has paid much attention to environmental protection, and theenvironmental requirement has increasingly improved. Magnesium hydroxide, one of theinorganic additive flame retardants, as a newly developed flame retardant, has attracted muchattention because of its good stability, non-volatile, environmental protection and higherdecomposition temperature. Since the domestic production of magnesium hydroxide has along synthesis route, low purity and yield, strong surface polarity and is unsuitable to add tosuch polymer materials as polypropylene. The research is aimed at the one-step synthesistechnology of magnesium hydroxide. Improving the purity and the yield , and bringing downthe surface polarity, this process has mild reaction condition, short process flow, smallequipment investment and low production cost. Therefore, this research has certain directivesignificance for magnesium hydroxide flame retardants industrial production.The thesis takes ultrasonic as the premise and takes the purity and yield as the index,using single factor experiment to test magnesium hydroxide production conditions, in theabstract, the optimal reaction condition was confirmed by orthogonal experiment. Using twocompound surface treatment agents as modification agent, modification effects wereinvestigated and contrasted. This study elementarily examined factors into compound of surfacetreatment and the modification mechanism of the surface treatment. Through test ing variousperformances of modificated magnesium hydroxide, the application in the polypropylene isforcasted.The experiment shows that the filtration problem of magnesium hydroxide obviouslyimproved by using ultrasonic processing in the initial stage of experiment. the best conditionsof synthesis were the initial concentration of Mg2+was 2.5 mol·L-1, the molar ration of NH3·H2O and Mg2+was 4.5 : 1, surface treating agent A was 5 mL, ultrasonication 2 min(impulse 4s), The reaction temperature was 55℃, and reaction time under constanttemperature was 2 h, The product quality is far superior to the industry standard. Throughvarious modification effect researches, the optimum dosage of surface treating agent A was 5mL, B was 8 mL, and the modification effect of A was better than that of B. This paperinvestigates when the anionic and nonionic surfactant mixed, the surface tension lowered. Thetwo surfactants with equal or similar carbon chain length have so strong interaction that theiractivity increased. Due to Compound of surfactant, magnesium hydroxide modificationdiversified, not limited to a single surfactant modification. The results indicated that thethermal stability of modified magnesium hydroxide was improved, the particle size becomesmaller, The size distribution was uniform, the polarity abated and made oil wettabilitystronger. This paper also predicts that magnesium hydroxide in the polypropylene has a gooddispersion and is not agglomerate in the the particles and the polymer compatibility isenhanced. Meanwhile the mechanical properties and processing properties of thepolypropylene compound material is ameliorated. From the above, the modified magnesiumhydroxide can achieve a good flame retardant effect.