Silicone rubber foam with ablation resistance and high-efficiency heat insulation and preparation method thereof

A silicone rubber foam with ablation resistance and high-efficiency heat insulation, comprising the following components in parts by weight for blending and foaming:

• a hydroxyl-terminated polydimethylsiloxane
• 100 parts;
• a vinyl-terminated polydimethylsiloxane
• 20 parts to 60 parts;
• a hydrogen-containing silicone oil
• 20 parts to 40 parts;
• a catalyst
• 0.4 parts to 1.5 parts;
• an inhibitor
• 0.1 parts to 0.5 parts;
• a ceramifiable emulsion foaming agent
• 5 parts to 10 parts;
• a functionalized ceramic filler
• 3 parts to 15 parts;
• a functionalized low-melting glass powder
• 3 parts to 15 parts;
• a functionalized hexagonal boron nitride
• 1 part to 5 parts;
• and
• a heat-resistant additive
• 1 part to 3 parts;
• wherein the ceramifiable emulsion foaming agent is a mixture of the following substances in parts by weight:
• the hydroxyl-terminated polydimethylsiloxane
• 100 parts;
• an emulsifier
• 5 parts to 15 parts;
• a high-melting glass powder
• 10 parts to 70 parts;
• a ceramic filler
• 10 parts to 70 parts;
• and
• a hydroxyl-modified hexagonal boron nitride
• 10 parts to 20 parts;
• and
• wherein:
• the hydroxyl-terminated polydimethylsiloxane of the ceramifiable emulsion foaming agent has a viscosity of 1,500 mPa·s to 50,000 mPa·s;
• the emulsifier is one or more selected from the group consisting of sorbitan monolaurate, sorbitan monostearate, and sorbitan monooleate;
• the high-melting glass powder has a melting point of 650° C. to 900° C.;
• the ceramic filler is one or more selected from the group consisting of montmorillonite, kaolin, wollastonite, and halloysite;
• the hydroxyl-modified hexagonal boron nitride is obtained by treating a hexagonal boron nitride at a high temperature of 900° C. to 1,200° C., cooling, and washing with deionized water;
• and
• wherein the emulsifier and the hydroxyl-terminated polydimethylsiloxane are dissolved by heating in a water bath and mixed uniformly, and the high-melting glass powder, the ceramic filler, and the hydroxyl-modified hexagonal boron nitride are added into the obtained mixture and mixed uniformly to obtain the ceramifiable emulsion foaming agent.