CN-122011398-A - Polyurethane foam homogenizing agent and preparation method thereof

Abstract

The invention discloses a polyurethane foam stabilizer and a preparation method thereof, and belongs to the technical field of polyurethane foam stabilizers, wherein the polyurethane foam stabilizer is polyether grafted polysiloxane formed by the reaction of allyl polyether containing Diels-Alder bonds and low-hydrogen silicone oil under the catalysis of a platinum catalyst. The allyl polyether containing Diels-Alder bonds is prepared by taking allyl-furfuryl glyceryl ether and polyfunctional maleimide as reaction monomers through Diels-Alder reaction. The introduced furan and aromatic components such as benzene rings in the polyfunctional maleimide structure obviously enhance the compatibility and affinity of the foam homogenizing agent and the aromatic oil phase raw materials in the polyurethane soft foam system. The foam stabilizer molecules can realize closer and more effective directional arrangement at the oil-water and oil-solid interfaces of the foaming system, thereby providing more excellent initial interface stabilizing effect.

Inventors

• WANG JUN
• CUI YAN
• JIANG HANTING
• WU HONGWEN

Assignees

• 安徽麦宸科技有限公司

Dates

Publication Date

20260512

Application Date

20260228

Claims (10)

1. 1. A polyurethane foam stabilizer is characterized in that the polyurethane foam stabilizer is polyether grafted polysiloxane formed by the reaction of allyl polyether containing Diels-Alder bonds and low-hydrogen silicone oil under the catalysis of a platinum catalyst.
2. 2. The polyurethane foam stabilizer as claimed in claim 1, wherein the allyl polyether containing Diels-Alder bonds is a Diels-Alder bond-containing allyl polyether prepared by a Diels-Alder reaction using allyl-furfuryl glyceryl ether and polyfunctional maleimide as reaction monomers.
3. 3. A polyurethane foam homogenizing agent according to claim 2, wherein the Diels-Alder bond containing allyl polyether is prepared by: Step S1, mixing furfuryl alcohol, sodium hydroxide and water, heating to 85-90 ℃ under the protection of nitrogen, dropwise adding allyl glycidyl ether, keeping the temperature unchanged after the addition, and continuously stirring for reacting for 3-4 hours to obtain allyl-furfuryl glycerol ether; And S2, adding allyl-furfuryl glyceryl ether and polyfunctional maleimide into chloroform, and stirring and reacting for 12-24 hours at the temperature of 60-70 ℃ to obtain the allyl polyether containing Diels-Alder bonds.
4. 4. A polyurethane foam stabilizer as claimed in claim 3 wherein the polyfunctional maleimide is at least one of 4,4' -bismaleimide diphenylmethane and tris (2-maleimidoethyl) amine.
5. 5. The polyurethane foam stabilizer as claimed in claim 4, wherein the ratio of the allyl furfuryl glyceryl ether to the polyfunctional maleimide is 3.5:3.8-7 by mass.
6. 6. The polyurethane foam stabilizer as claimed in claim 4, wherein the ratio of allyl furfuryl glycerol ether to 4,4' -bismaleimide diphenylmethane is 3.5:5.8-6 by mass.
7. 7. The polyurethane foam stabilizer as claimed in claim 4, wherein the ratio of the allyl furfuryl glyceryl ether to the tri (2-maleimidoethyl) amine is 3.5:3.8-4 by mass.
8. 8. The polyurethane foam stabilizer as claimed in claim 1, wherein the low-hydrogen silicone oil has a mass fraction of medium hydrogen of 0.1 to 0.3%, a viscosity of 20 to 100 mPas, and the ratio of the amount of Diels-Alder bond-containing allyl polyether to the mass fraction of low-hydrogen silicone oil of 60 to 70:100.
9. 9. A process for preparing a polyurethane foam stabilizer, for preparing a polyurethane foam stabilizer as defined in any one of claims 1 to 8, comprising the steps of: Adding Diels-Alder bond-containing allyl polyether into an organic solvent, adding a platinum catalyst under the protection of nitrogen, heating to 50-52 ℃, stirring for 30-60min, adding low-hydrogen silicone oil, setting the temperature to 60-70 ℃ after the addition is finished, stirring and reacting for 24-36h, and removing toluene by rotary evaporation after the reaction is finished to obtain the polyurethane foam stabilizer.
10. 10. The preparation method of the polyurethane foam stabilizer according to claim 9, wherein the addition amount of the platinum catalyst is 30-40ppm of the total mass of allyl polyether containing Diels-Alder bonds and low hydrogen silicone oil, and the organic solvent is toluene.

Description

Polyurethane foam homogenizing agent and preparation method thereof Technical Field The invention belongs to the technical field of polyurethane foam homogenizing agents, and particularly relates to a polyurethane foam homogenizing agent and a preparation method thereof. Background Polyurethane foam is a material that undergoes complex chemical reactions from a variety of raw materials in a very short time, and from a liquid, a polymer is ultimately formed by a colloid. The process covers a plurality of key stages of foaming, curing and the like, and the stability and uniformity of the system are important. In this process, the foam stabilizer (also known as foam stabilizer) plays an irreplaceable regulatory role, which ensures that a foam product is obtained that foams uniformly, structurally stable by lowering the system surface tension, emulsifying the components, stabilizing the cell growth and regulating the final cell structure. If no foam homogenizing agent is regulated, the foam is extremely easy to have defects such as collapse, kong Cu, cracking and the like. At present, the foam homogenizing agent widely used in the polyurethane industry is mainly polyether modified polysiloxane surfactant. Such molecules are typically composed of a hydrophobic polysiloxane backbone and hydrophilic polyether side chains, the hydrophilic-lipophilic balance of which can be adjusted by precisely designing the type, length, number and manner of attachment of the two segments, thereby accommodating different foaming systems. For example, in the production of flexible foams, an ideal foam homogenizing agent needs to fully emulsify the raw materials at the early stage of foaming, stabilize the newly generated cells, and promote timely "open cells" at the later stage to ensure the softness and breathability of the foam. Aiming at the performance optimization of the foam stabilizer, most of the prior art schemes focus on modification and adjustment of polyether segments. For example, there are patent techniques that utilize different values of the hydrophilic-lipophilic balance of two polyether-modified polysiloxane components of different degrees of polymerization and molecular weights by compounding them to enhance the overall emulsifying properties. In addition, the technical proposal focuses on improving the end capping rate of the polyether chain segment and controlling the narrowness of the molecular weight distribution of the polyether chain segment, and aims to eliminate the influence of residual hydroxyl, enhance the chemical stability of the foam homogenizing agent and further improve the foam homogenizing effect. In addition, by precisely controlling the molecular weight ratio of the hydrogen-containing silicone oil and the allyl polyether and the conversion rate of the hydrosilylation reaction, the method also becomes an effective means for designing the universal foam stabilizer. Despite the advances made in the above-described polyether segment adjustment-based techniques, significant limitations remain. These improvements have focused mainly on polyether segments as hydrophilic groups, aimed at enhancing their ability to solubilize and emulsify aqueous or polar components, but have generally ignored targeted functional modifications to the polysiloxane backbone as lipophilic groups. Oil phase raw materials of the polyurethane soft foam, such as Toluene Diisocyanate (TDI), diphenylmethane diisocyanate (MDI) and modified products thereof, are aromatic compounds containing benzene rings and have specific polarity. Whereas the polysiloxane backbone (Si-O-Si structure) of conventional foam homogenizing agents is inherently more compatible with non-polar alkanes, the compatibility with the above aromatic oil phase materials is generally poor. The lack of compatibility results in difficulty in achieving the most effective directional adsorption and tight arrangement of the foam stabilizer molecules at the oil-water (or oil-solid) interface of the foaming system, thereby weakening the core functions of the foam stabilizer molecules in reducing interfacial tension and stabilizing the foam walls, and making the emulsification and foam stabilizing effects not expected. This defect is further amplified in the complex foaming environment of the soft foam. The soft bubble reaction produces a large number of insoluble substituted urea particles, and if the hydrophobic segment of the foam stabilizer has poor compatibility with the hydrophobic segment, the solid particles cannot be effectively wetted and dispersed, so that the solid particles are locally accumulated on the cell wall, the continuity of the film is broken, and finally, the cell breakage and the overall collapse are initiated. Therefore, a novel foam homogenizing agent is needed in the art to solve the problems of insufficient stability, easy collapse, poor uniformity of cells and the like of polyurethane foam in the prior art. Disclosure of Invention The inve