Experimental Research On The Effect Of Typical Inorganic Additives On The Flame Retardancy Of Silicone Rubber Foam

Silicone rubber as one of the main polymer materials,has unique and excellent characteristics Generally,the limiting oxygen index(LOI)of silicone rubber is higher than that of a polymer material with a carbon backbone as the main chain.And It p.roduces less heat and smoke during c.ombustion.However,silicone rubber may still burn in the event of an open flame,and there is a certain risk of fire.In addition,because of the increasing demands of the state on the fire risk of macromolecule materials,it is of practical significance to study the combustion characteristics of silicone rubber and to explore ways to improve its flame retardant performance.This paper chooses liquid silicone rubber as the base glue,and dehydrogenation type RTV-2 foam material is prepared by dehydrogenation foaming and room-temperature catalytic cross-linking.Aluminum hydroxide(ATH),magnesium hydroxide(MDH),calcium carbonate(CC),talc,and hollow glass microspheres(HGB)were then selected as flame retardant additives.Finally,flame-retardant silicone rubber foams were prepared by mechanical blending method.The effects of platinum catalysts and various inorganic additives on the combustion characteristics,flame-retardant properties and mechanical properties of the materials were studied.This article mainly has the following research content.The effects of the addition of platinum catalysts on the combustion characteristics,flame retardant properties,mechanical properties and curing time of dehydrogenated RTV-2 foam materials were studied.Combined with TG-DTG testing,cone calorimetry and previous studies,it was found that platinum catalysts can affect the thermal stability and flame retardancy of materials.The platinum catalysts have greatly accelerated the cross-linking reaction rate of silicone rubber by recording the curing time of the material,which is not conducive to sample preparation,so it should be added in an appropriate amount.Then,the effects of inorganic additives ATH,MD,CC,talcum powder and HGB on the combustion characteristics,flame retardancy and mechanical properties of dehydrogenated RTV-2 foams were studied.In combination with TG-DTG test,cone calorimeter tests and studies of scholars,compare and analysis the ATH,MDH,CC,talcum powder and flame retardant mechanism of the respective HGB and flame retardant effect,the improved dehydrogenation type RTV-2 foam flame retardant performance appropriate proportion of added.The effects of the ATH/CC compound additives and talcum powder/HGB compound additives on the flame retardant properties of the dehydrogenated RTV-2 foam materials were analyzed,and the mechanism of the flame retardant synergistic mechanism between them was discussed.Then,it analyzed the optimal combination ratio of the samples,including 1wt%HGB and 30wt%talcum powder.