Method for preparing organosilicon foam using hydrogen-containing silicone oil modified by phosphorus flame retardant

Abstract

The invention discloses a method for preparing silicone foam using hydrogen-containing silicone oil modified by a phosphorus-based flame retardant, including S1. reacting a hydroxyl-terminated phosphorus-based liquid flame retardant and hydrogen-containing silicone oil to synthesize a modified phosphorus-based flame retardant Hydrogen-containing silicone oil; S2. Evenly mix vinyl silicone oil and hydroxyl silicone oil; S3. Add modified hydrogen-containing silicone oil, stir and let it stand until the mixture turns into a white translucent gel block solid; S4. Foam molding ; S5. Gradient high-temperature treatment to obtain a flame-retardant silicone foam material, its limiting oxygen index is 27-45, and the density is 0.2-0.4g / cm 3 , the tensile strength is 110‑380kPa. The invention relies on the reaction between the hydroxyl-terminated phosphorus-based liquid flame retardant and hydrogen-containing silicone oil to realize the quantitative and large-scale introduction of the phosphorus-based liquid flame retardant on the silicone matrix resin, and the prepared silicone foam has high flame-retardant performance , High mechanical properties and stable structure.

Description

technical field [0001] The invention relates to the field of organosilicon foam materials, in particular to a method for preparing organosilicon foam using hydrogen-containing silicone oil modified by a phosphorus-based flame retardant. Background technique [0002] Because of its structure of -Si-O-Si- as the main chain and organic groups as side chains, organosilicon polymers have excellent properties such as chemical stability, physiological inertness, good high and low temperature resistance, and electrical insulation. On this basis, silicone foam materials also have the advantages of high flexibility, light weight, high elasticity, sound absorption, high ductility and other advantages of foam materials, and have broad development prospects, and their shape memory function is favored by the field of polymer foaming recognized by the vast number of scientific researchers. In the preparation process of silicone foam materials, hydrogen gas is usually generated by the reac...

AI Technical Summary

Problems solved by technology

However, the existence of a large number of aliphatic hydrocarbon groups on the side chains of the silicone polymer matrix resin composed of hydroxyl silicone oil and hydrogen-containing silicone oil makes it extremely flammable, and the limiting oxygen index value is still less than 20%.

Although it avoids the direct use of phosphorus-based liquid flame retardants that are prone to serious volatilization during high-temperature curing or processing, the high-temperature environment and generated water molecules in the preparation process of this method will cause the phosphorus-based flame retardants to decompose. Polyhydrolysis problem phenomenon, resulting in ineffective introduction of

In addition, under high temperature conditions, the hydroxyl-terminated phosphorus-based flame retardants that have time to participate in the polymerization reaction will also show a certain amount of volatilization.

The existence of the above two factors makes it impossible to accurately and quantitatively introduce hydroxyl-terminated phosphorus-based flame retardants, and also causes a decline in the flame-retardant effect of phosphorus-based flame retardants, which ultimately affects the flame-retardant and other properties of silicone foam materials

Therefore, the existing method of preparing silicone foam by using hydrogen-containing silicone oil, hydroxyl silicone oil and phosphorus-based liquid flame retardants has the problems of reduced flame retardant effect and reduced mechanical properties.

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