Preparation method of rigid foam flame-retardant polyether polyol for all-water foaming

Abstract

The invention belongs to the technical field of polyurethane synthesis, and in particular relates to a preparation method of a rigid foam flame-retardant polyether polyol for all-water foaming. The preparation method uses sucrose, a low-molecular-weight polyol, a halogenated alcohol, phenolic resin, and oil as initiators, and uses an alkali metal salt as a catalyst, and a section of propylene oxide is introduced for carrying out a reaction; and after the reaction is completed, a mixture of propylene oxide and ethylene oxide is introduced for carrying out a mixed polymerization reaction, and acrude ether is purified by post-treatment to obtain a finished product. The technological process is simple in operation, the obtained rigid foam flame-retardant polyether product for all-water foaming has low viscosity and good compatibility with water, a polyurethane foam plastic product prepared from the polyether product has relatively narrow density distribution, relatively high strength, good dimensional stability and bonding strength, and relatively low thermal conductivity, has certain flame-retardant effects, and is especially suitable for all-water foamed thermal insulation pipes andother thermal insulation fields.

Description

technical field [0001] The invention belongs to the technical field of polyurethane synthesis, and in particular relates to a preparation method of rigid foam flame-retardant polyether polyol for all-water foaming. Background technique [0002] In the prior art, various foaming agents are used for foaming rigid polyether polyols. At present, CFC systems are mostly used as foaming agents, among which HCFC-141B is the main one, and some even use Freon-11, which is banned by the state. etc., but this type of blowing agent is not friendly to the environment and brings certain environmental hazards. In recent years, many units or individuals have developed some all-water rigid polyether polyols, replacing the foaming agent with water. The technology of all-water foamed rigid polyether polyols uses carbon dioxide generated by the reaction of water and isocyanate as the foaming gas. The ODP (Ozone Depletion Potential) is zero, and the GWP (Greenhouse Gas Effect) is 1, which is fri...

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Problems solved by technology

However, the rigid foam polyether polyol synthesis process in the prior art has the following disadvantages: (1) the full water foamed rigid polyether polyol product prepared by this process has large viscosity, high hydroxyl value, and the full water foam In the polyether composite material, because there are no physical blowing agents such as CFC and HCFC that can be used as diluents, the viscosity of the compound composite material is high, and the mold filling property is poor when processing foam products; (2) rigid foam polyether in the prior art Ether polyol is when carrying out all-water foaming, and the speed that foaming gas carbon dioxide diffuses outwards from foam hole is 1.0 times faster than the speed that air enters foam hole, causes foam shrinkage, collapses easily; (3) in the prior art When the rigid foam polyether polyol is fully water-foamed, due to the large amount of water used, it reacts with isocyanate to form more urea bonds, resulting in brittle foam and weak adhesion to the insulation system; (4) The rigid polyether polyols used for full water foaming in the existing technology have the disadvantage of poor flame retardant effect, and mainly rely on the addition of non-reactive small molecule flame retardants containing halogens, phosphorus, and inorganic salts to improve the flame retardant properties of materials. Flame retardant performance, however, externally added non-reactive flame retardants have disadvantages such as poor storage stability in the composite material, affecting the strength of the product, and easy migration out of the product; (5) full water foaming in the prior art Using rigid polyether polyol, the production process is complicated and the cost is high, so its market share is very low, and it has encountered great resistance in the process of actual promotion and application

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