Effects Of The Magnesium-series Flame Retardant Agents On The Properties Of Polysilicone Sealant

Polysilicone sealant is a type of silicone robber polymer materialswith the excellent performance. It posses many advantages, such as good high and low temperature tolerance, good electric insulation, good anti-aging, outstanding surface active properties, etc. It is also characterized by free-toxicity, Physiological inert, etc. It has been widely used in many industries, especially electronics and electrical and aerospace industries. However, many shortcomings, such as low intensity and flammability, namely, without flame retardant function, etc., limit its application. With the rapid development of our modern industries, especially aerospace industry, the requirements of materials performance are getting increasingly harsh. At present, China's production safety situation has become more and more serious and the safety requirement of the material has increased continuously. So it is significant to modify the polysilicone sealant to improve its comprehensive performance, especially the flame-retardant property. This research has broad market prospects.Magnesium hydroxide, an inorganic material with wide source, low-cost and high decomposition temperature, has a series of advantages, for example, nitrogen-free, low-fuming, non-corrosive processing equipment, non-harmful gases released, higher temperature than the decomposition temperature of aluminum hydroxide and favorable to be used in the polymers requiring a higher work temperature. In recent years, the amount has become more and more large and been widely recognized by the market. China's very rich in magnesium resources, but not yet fully exploited. How to expand the scope of application of magnesium and develop their new uses is the urgent need of the times. It is of great significance to reduce environmental pollution, raise the utilization rate of resources and improve cyclic economic.After extensive analysis, this work selected the magnesium hydroxide with special morphology to act as a flame retardant and monocomponent, dealcoholization room-temperature vulcanized (RTV) silicone sealant to be used as a bulk material to study. The production and the surface modification of magnesium hydroxide have been studied and the suitable surface modifier has been selected. Then the magnesium hydroxide with surface modification has been added according to different proportions to the RTV silicone sealant. The effects of it on the mechanical and flame-retardant Properties of the monocomponent, dealcoholization RTV silicone sealant have been investigated.Experimental section: The monocomponent, dealcoholization flame-retardant RTV silicone sealant was prepared withα,ω-dihydroxypolydimethylsilicone as the basic gel, carbon-white prepared with gas phase method as the stuffing and the surface-modification magnesium hydroxide with special morphology as flame retardant agent. The effects of the modified magnesium hydroxide on the mechanical and flame-retardant properties of the monocomponent, dealcoholization RTV silicone sealant have been studied. The results show that when 100 copies of the quality of bulk materials were added to the 50 copied of quality of magnesium hydroxide flame retardant, the LOI of the RTV silicone sealant amounts to 35.1%. It has the better flame-retardant property and maintains good sealing performance.