Study On The Preparation And Performance Of Intrinsic Flame-retardant Silicone Foam

Silicone foam is a kind of material that has the advantages of silicone’s high and low temperature resistance,weather resistance and other advantages,as well as light weight,heat insulation and sound insulation of the foam material.It has a wide range of applications in electromagnetic shielding,oil-water separation,wearable devices and construction.However,traditional silicone foam materials are foamed with silicone rubber as the matrix.The prepared foam materials have good elasticity,but they are burnable and have no flame retardancy.Most of them are made by adding flame retardants.It is flame-retardant.This article attempts to use silicone resin as the matrix,and use chemical foaming method and physical foaming method to prepare organic silicon foam material,so that the prepared organic silicon foam material has more silicon oxide silicon structure,without the addition of flame retardants.It has flame retardant properties.The first chapter uses Piers-Rubinsztaj n reaction to react pendant alkoxy polysiloxane with hydrogen-containing polysiloxane to prepare silicone foam.The second chapter uses hydrogen-containing polysiloxane to react with alkaline catalyst to prepare silicone foam.The third chapter uses pendant methoxy polysiloxane as the matrix and uses the physical foaming method to prepare silicone foam.The main work is as follows1.Use pendant alkoxy polysiloxane and hydrogen-containing polysiloxane to undergo Piers-Rubinsztaj n reaction under the catalysis of tripentafluorophenylborane to explore the pair of hydrogen-containing polysiloxanes with different hydrogen content.The effect of the performance of the foam material,the result is that when the alkoxy content of the pendant alkoxy polysiloxane is 1.07%,which is the highest content,when the hydrogen content of the hydrogen-containing polysiloxane is 1.6%,the prepared The silicone foam has the best flame-retardant performance.It can reach the V-0 level after the vertical combustion test,and the limiting oxygen index is 32%.After thermal weight loss test,the residual weight can reach 77.02wt%at 1000℃.The lowest density of silicone foam can reach 0.25g/cm-3,the corresponding porosity is 82.36%,and the lowest thermal conductivity is 0.057 W/m·k.In addition,the foam material has been subjected to a compression test,and the compressive strength can reach up to 62KPa.2.Use hydrogen-containing polysiloxane to react with alkali catalyst to prepare organosilicon foam material.Hydrogen-containing polysiloxanes with different hydrogen content are used to react with alkaline catalysts.The study found that the basic catalyst can catalyze the dehydrogenation condensation of organosilicon and the Piers-Rubinsztajn reaction,and double gas production to prepare a silicone foam material with a bimodal cell structure.As the amount of catalyst increases,the foaming time gradually decreases.Small,when using hydrogen-containing polysiloxane with a maximum hydrogen content of 1.6%for foaming,silicone foam has the best flame retardant performance,UL-94 test can reach V-0 level,and limit oxygen index can reach 27.3%.After the thermal weight loss test,the residual weight at 1000℃ can reach 76.82wt%.3.Use n-hexane as a physical foaming agent and pendant methoxy polysiloxane as a matrix to prepare silicone foam materials.By exploring the pre-curing time of pendant methoxy polysiloxane,the amount of n-hexane,the amount of foam stabilizer L580 and the influence of foaming temperature on silicone foam.The study found that when the amount of pendant methoxy polysiloxane is 10g,the amount of catalyst is 0.1g,the amount of n-hexane is 1g,the amount of foam stabilizer L580 is 1g,and the foaming temperature is 70℃,the pre-curing time is 170min,and the foaming effect is better.Good,the oxygen index of the prepared silicone foam can reach 30%,and the vertical combustion test is V-0 level.