A polyurethane foam stabilizer and its preparation method

Abstract

The present invention relates to the technical field of polyurethane foam, and specifically relates to a polyurethane foam stabilizer and a preparation method thereof. The polyurethane foam stabilizer in the present invention comprises the following materials in parts by weight: 50 - 70 parts of polyether-modified polysiloxane, prepared by hydrosilylation reaction of isocyanate-terminated unsaturated polyether and low hydrogen content silicone oil; 20 - 30 parts of an auxiliary stabilizing component, which is a polyoxyethylene ether containing a furan ring and has a number average molecular weight of 3000 - 5000; 5 - 10 parts of a functional additive, which is a polyoxyethylene ether containing an azobenzene structure and has a number average molecular weight of 1000 - 2000. The polyurethane foam obtained by the preparation method in the present invention can effectively improve the stability of the polyurethane foam and can also reduce the thermal conductivity of the polyurethane foam to a certain extent.

Description

Technical Field

[0001] The invention relates to the technical field of polyurethane foam, and particularly relates to a polyurethane foam stabilizer and a preparation method thereof. Background Art

[0002] A polyurethane foam stabilizer is a substance that can reduce the surface tension of a polyurethane raw material mixture. During the period from the rise to the ripening of the foam, it prevents the appearance of the thermodynamic non-steady state of the foam through surface tension, thereby promoting nucleation and stabilizing the pores and each raw material in the emulsion system, so that the obtained foam plastic products have excellent physical and mechanical properties.

[0003] The main functions of a polyurethane foam stabilizer include emulsification, nucleation, and stabilization. The emulsification function refers to emulsifying each component into a homogeneous body to improve the stability and fluidity of the raw material system; the nucleation function refers to promoting the formation of air bubbles during the foam formation process; the stabilization function is to adjust the pore size of the foam to make the foam have an ideal open-cell or closed-cell structure, thereby improving the mechanical properties, heat insulation properties, and sound insulation properties of the foam.

[0004] There are various existing polyurethane foam stabilizers, mainly including silicone foam stabilizers, non-silicone foam stabilizers, and composite foam stabilizers, etc. Among them, the silicone foam stabilizer has a polysiloxane main chain and a copolymerized ether side chain, and has strong emulsifying ability and nucleating ability, and is widely used in the preparation of rigid and soft polyurethane foams. The action principle of the silicone foam stabilizer mainly depends on its special molecular structure. The polysiloxane main chain has hydrophobicity and can reduce the surface tension of the system, while the copolymerized ether side chain has hydrophilicity and can enhance the interaction between each component, thereby improving the stability of the foam. However, the stability effect that can be achieved by the existing polyurethane foam stabilizers is not good. Based on this, the present invention provides a polyurethane foam stabilizer and a preparation method thereof. Summary of the Invention

[0005] The purpose of the present invention is to provide a polyurethane foam stabilizer and a preparation method thereof. The stability of the polyurethane foam prepared by using this stabilizer is improved, and the thermal conductivity of the polyurethane foam can also be reduced to a certain extent.

[0006] In a first aspect, the present invention provides a polyurethane foam stabilizer, which comprises the following raw materials in parts by weight:

[0007] 50 - 70 parts of polyether-modified polysiloxane, prepared by a hydrosilylation reaction of an isocyanate-terminated unsaturated polyether and a low hydrogen content silicone oil;

[0008] 20 - 30 parts of an auxiliary stabilizing component, which is a polyoxyethylene ether containing a furan ring and has a number average molecular weight of 3000 - 5000;

[0009] 5 - 10 parts of functional additive, which is a polyoxyethylene ether containing azobenzene structure and has a number average molecular weight of 1000 - 2000.

[0010] Furthermore, the preparation method of the polyether modified polysiloxane includes:

[0011] (1) Preparation of isocyanate - terminated unsaturated polyether: Allyl alcohol, ethylene oxide, and propylene oxide are reacted at a ratio under an alkaline catalyst at a temperature of 90 - 120 °C and a pressure ≤ 0.5 MPa to obtain allyl - terminated polyether; toluene diisocyanate is added for end - capping reaction, with a reaction temperature of 60 - 80 °C and a time of 2 - 4 hours to form isocyanate - terminated polyether;

[0012] (2) Preparation of low - hydrogen - content silicone oil: Octamethylcyclotetrasiloxane, hexamethyldisiloxane, and hydrogen - containing silicone oil with a hydrogen content ≥ 1% are reacted under the catalysis of an acidic ion - exchange resin at a temperature of 50 - 70 °C and a time of 3 - 5 h to obtain low - hydrogen - content silicone oil with a hydrogen content of 0.3 - 0.8%;

[0013] (3) Hydrosilylation: The isocyanate - terminated unsaturated polyether and low - hydrogen - content silicone oil are mixed at a mass ratio of 4 - 6:1, a chloroplatinic acid catalyst is added, and the reaction is carried out at 80 - 100 °C for 2 - 4 h to form polyether modified polysiloxane.

[0014] Furthermore, the alkaline catalyst is sodium hydroxide.

[0015] Furthermore, the weight - part ratio of allyl alcohol, ethylene oxide, propylene oxide, alkaline catalyst, and toluene diisocyanate is (5 - 8):(15 - 20):(45 - 60):(0.5 - 1.5):(8 - 12).

[0016] Furthermore, the weight - part ratio of octamethylcyclotetrasiloxane, hexamethyldisiloxane, hydrogen - containing silicone oil, and acidic ion - exchange resin catalysis is (70 - 85):(10 - 15):(5 - 10):(2 - 3).

[0017] Furthermore, the acidic ion - exchange resin includes any one of Amberlyst 15, Amberlyst 35, and D001 type.

[0018] Further, the preparation method of the furan ring-containing polyoxyethylene ether includes: adding furfurylamine and methyl acrylate into ethanol, heating to 60 - 70 °C under nitrogen protection, dropwise adding tetrabutylammonium bromide and reacting for 4 - 6 hours, and obtaining a furan-acrylate intermediate after removing ethanol by vacuum distillation; putting the above intermediate and ethylene oxide into a high-pressure reactor according to a molar ratio of 1:25 - 30, adding a KOH catalyst; gradually heating to 120 - 140 °C, controlling the pressure ≤ 0.8 MPa, and reacting for 6 - 8 hours; filtering after neutralization and dehydrating with molecular sieve to obtain the product.

[0019] Further, the weight ratio of furfurylamine, methyl acrylate, ethanol, and tetrabutylammonium bromide is (10 - 15):(85 - 90):(280 - 320):(0.2 - 0.3).

[0020] Further, the preparation method of the azobenzene structure-containing polyoxyethylene ether includes: mixing 4-hydroxyazobenzene and sodium metal in toluene, stirring at 70 - 80 °C for 2 - 3 h under nitrogen protection to generate a sodium salt active intermediate; transferring the active intermediate to a high-pressure kettle, slowly introducing ethylene oxide, controlling the temperature at 100 - 110 °C, the pressure ≤ 0.5 MPa, reacting for 3 - 4 hours, adding glacial acetic acid to neutralize to neutrality, and filtering to obtain the product.

[0021] Further, the weight ratio of 4-hydroxyazobenzene, sodium metal, and toluene is (5 - 8):(0.1 - 0.3):100, and the molar ratio of the active intermediate and ethylene oxide is 1:15 - 20.

[0022] In the second aspect, the preparation method of this polyurethane foam stabilizer includes the steps of mixing polyether-modified polysiloxane, furan ring-containing polyoxyethylene ether, and azobenzene polyoxyethylene ether in proportion to obtain a mixed material, adding triethylamine accounting for 0.5 - 1% of the weight of the mixed material, and stirring at 60 - 70 °C for 2 - 3 hours to obtain the product.

[0023] The beneficial effects of the present invention are as follows:

[0024] The present invention prepares a polyether-modified polysiloxane with a special structure through a hydrosilylation reaction of an isocyanate-terminated unsaturated polyether and a low-hydrogen-content silicone oil. This structure not only improves the interfacial compatibility but also significantly improves the uniformity of the cell structure; introducing a furan ring-containing polyoxyethylene ether as an auxiliary stabilizing component strengthens the intermolecular crosslinking network through π-π interaction, thereby enhancing the thermal stability; introducing an azobenzene structure-containing polyoxyethylene ether as a functional additive utilizes the light-responsive characteristics of the azobenzene group to achieve dynamic regulation of the cell structure; in addition, through the synergistic effect of polyether-modified polysiloxane, furan ring-containing polyoxyethylene ether, and azobenzene structure-containing polyoxyethylene ether, the stability and performance of the polyurethane foam are jointly improved.

[0025] In the present invention, the polyether-modified polysiloxane combines the advantages of polyether and polysiloxane, has excellent flexibility and interfacial compatibility. The isocyanate-terminated unsaturated polyether can react with the isocyanate groups in the polyurethane system to form chemical bond connections, thereby enhancing the interfacial bonding force. At the same time, the flexibility of the polysiloxane main chain helps to improve the uniformity of the cell structure and reduce the thermal conductivity.

[0026] In the present invention, the polyoxyethylene ether containing a furan ring forms a cross-linked network with other components in the polyurethane system through π-π interactions. This cross-linked structure can enhance the thermal stability of the foam and prevent the cell structure from collapsing or deforming at high temperatures. At the same time, the introduction of the furan ring also helps to improve the weather resistance and aging resistance of the foam.

[0027] In the present invention, the azobenzene group has a light-responsive property and can undergo conformational changes under light illumination conditions. This conformational change can affect the structure and distribution of the cells in the foam, thereby realizing the dynamic regulation of the cell structure. By adjusting the light illumination conditions and the content of the azobenzene group, the properties such as the density, hardness, and thermal conductivity of the foam can be precisely controlled.

[0028] In the present invention, there is a synergistic effect among the polyether-modified polysiloxane, the polyoxyethylene ether containing a furan ring, and the polyoxyethylene ether containing an azobenzene structure. The polyether-modified polysiloxane provides the main chain flexibility, which helps to improve the uniformity of the cell structure and reduce the thermal conductivity; the polyoxyethylene ether containing a furan ring enhances the thermal stability and prevents the cell structure from collapsing or deforming; the polyoxyethylene ether containing an azobenzene structure realizes the dynamic regulation of the cell structure through its light-responsive property. The combined action of the three makes the polyurethane foam have excellent stability and performance. Detailed Embodiments

[0029] The technical solutions of the present invention will be described clearly and completely below. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0030] It should be noted that the hydrogen-containing silicone oil with a hydrogen content ≥1% in the specific embodiments of the present invention is of the model CR-F22H, produced by Hubei Kewode Chemical Co., Ltd.

[0031] Example 1

[0032] In this example, a polyurethane foam stabilizer is provided, which comprises the following raw materials in parts by weight:

[0033] 60 parts of polyether-modified polysiloxane, prepared by the hydrosilylation reaction of isocyanate-terminated unsaturated polyether and low-hydrogen-content silicone oil;

[0034] 25 parts of auxiliary stabilizing component, which is a polyoxyethylene ether containing a furan ring and has a number-average molecular weight of 4000;

[0035] 7 parts of functional additive, which is a polyoxyethylene ether containing an azobenzene structure and has a number-average molecular weight of 1500;

[0036] Among them, the preparation method of the polyether-modified polysiloxane includes:

[0037] (1) Preparation of isocyanate-terminated unsaturated polyether: Allyl alcohol, ethylene oxide, and propylene oxide are reacted in proportion under the conditions of alkaline catalyst sodium hydroxide, temperature of 105 °C, and pressure of 0.5 MPa to obtain allyl-terminated polyether; toluene diisocyanate is added for end-capping reaction, the reaction temperature is 70 °C, and the time is 3 hours to generate isocyanate-terminated polyether; the weight ratio of allyl alcohol, ethylene oxide, propylene oxide, alkaline catalyst, and toluene diisocyanate is 6:17:48:1:10;

[0038] (2) Preparation of low-hydrogen-content silicone oil: Octamethylcyclotetrasiloxane, hexamethyldisiloxane, and hydrogen-containing silicone oil with a hydrogen content ≥ 1% are reacted under the catalysis of acidic ion exchange resin at a temperature of 60 °C for 4 hours to obtain low-hydrogen-content silicone oil with a hydrogen content of 0.5%; the weight ratio of octamethylcyclotetrasiloxane, hexamethyldisiloxane, hydrogen-containing silicone oil, and acidic ion exchange resin catalysis is 80:12:7:2.5; the acidic ion exchange resin is of D001 type;

[0039] (3) Hydrosilylation: The isocyanate-terminated unsaturated polyether and low-hydrogen-content silicone oil are mixed in a mass ratio of 5:1, and 0.21% of chloroplatinic acid catalyst relative to the total weight of the materials is added, and the reaction is carried out at 90 °C for 3 hours to generate polyether-modified polysiloxane.

[0040] Among them, the preparation method of the polyoxyethylene ether containing a furan ring includes: Furfuralamine and methyl acrylate are added to ethanol, and under nitrogen protection, the temperature is raised to 65 °C, tetrabutylammonium bromide is added dropwise and reacted for 5 hours, and ethanol is removed by vacuum distillation to obtain a furan-acrylate intermediate. The above intermediate and ethylene oxide are put into a high-pressure reaction kettle in a molar ratio of 1:27, and 0.3% of KOH catalyst relative to the total weight of the materials is added; the temperature is gradually raised to 130 °C, the pressure is controlled at 0.8 MPa, and the reaction is carried out for 7 hours; after neutralization and filtration, it is dehydrated by molecular sieve to obtain; the weight ratio of furfuralamine, methyl acrylate, ethanol, and tetrabutylammonium bromide is 12:87:300:0.25.

[0041] Among them, the preparation method of the polyoxyethylene ether containing an azobenzene structure includes: mixing 4-hydroxyazobenzene with metallic sodium in toluene, stirring at 75 °C for 2.5 h under nitrogen protection to generate a sodium salt active intermediate; transferring the active intermediate to an autoclave, slowly introducing ethylene oxide, controlling the temperature at 105 °C and the pressure at 0.5 MPa, reacting for 3.5 hours, adding glacial acetic acid to neutralize to neutrality, and filtering to obtain; the weight part ratio of 4-hydroxyazobenzene, metallic sodium and toluene is 6:0.2:100, and the molar ratio of the active intermediate to ethylene oxide is 1:17.

[0042] The preparation method of this polyurethane foam stabilizer includes the steps of mixing a polyether-modified polysiloxane, a polyoxyethylene ether containing a furan ring, and an azobenzene polyoxyethylene ether in proportion to obtain a mixed material, and adding triethylamine accounting for 0.7% by weight of the mixed material, and stirring at 65 °C for 2.5 hours to obtain.

[0043] Example 2

[0044] In this example, a polyurethane foam stabilizer is provided, which includes the following raw materials in parts by weight:

[0045] 50 parts of polyether-modified polysiloxane, prepared by hydrosilylation reaction of an isocyanate-terminated unsaturated polyether and a low hydrogen content silicone oil;

[0046] 20 parts of auxiliary stabilizing component, which is a polyoxyethylene ether containing a furan ring, with a number average molecular weight of 3000;

[0047] 5 parts of functional additive, which is a polyoxyethylene ether containing an azobenzene structure, with a number average molecular weight of 1000;

[0048] Among them, the preparation method of the polyether-modified polysiloxane includes:

[0049] (1) Preparation of isocyanate-terminated unsaturated polyether: Reacting allyl alcohol, ethylene oxide, and propylene oxide in proportion under the conditions of a basic catalyst sodium hydroxide, a temperature of 90 °C, and a pressure of 0.4 MPa to obtain an allyl-terminated polyether; adding toluene diisocyanate for a capping reaction, with a reaction temperature of 60 °C and a time of 2 hours to generate an isocyanate-terminated polyether; the weight part ratio of allyl alcohol, ethylene oxide, propylene oxide, basic catalyst, and toluene diisocyanate is 5:15:45:0.5:8;

[0050] (2) Preparation of low hydrogen - containing silicone oil: Octamethylcyclotetrasiloxane, hexamethyldisiloxane and hydrogen - containing silicone oil with a hydrogen content ≥ 1% are reacted under the catalysis of acidic ion - exchange resin at a temperature of 50 °C for 3 h to obtain low hydrogen - containing silicone oil with a hydrogen content of 0.3%; the weight - part ratio of octamethylcyclotetrasiloxane, hexamethyldisiloxane, hydrogen - containing silicone oil and acidic ion - exchange resin catalysis is 70:10:5:2; the acidic ion - exchange resin is Amberlyst 15;

[0051] (3) Hydrosilylation: The isocyanate - terminated unsaturated polyether and low hydrogen - containing silicone oil are mixed in a mass ratio of 4:1, and 0.21% of chloroplatinic acid catalyst relative to the total weight of the materials is added, and the reaction is carried out at 80 °C for 2 h to generate polyether - modified polysiloxane;

[0052] Among them, the preparation method of the polyoxyethylene ether containing a furan ring includes: adding furfurylamine and methyl acrylate to ethanol, heating to 60 °C under nitrogen protection, dropping tetrabutylammonium bromide and reacting for 4 h, and then obtaining the furan - acrylate intermediate by vacuum distillation to remove ethanol. The above intermediate and ethylene oxide are put into a high - pressure reactor in a molar ratio of 1:25, and 0.3% of KOH catalyst relative to the total weight of the materials is added; gradually heating to 120 °C, controlling the pressure at 0.8 MPa, and reacting for 6 h; after neutralization, filtration is carried out, and dehydration with molecular sieve is carried out to obtain it; the weight - part ratio of furfurylamine, methyl acrylate, ethanol and tetrabutylammonium bromide is 10:85:280:0.2.

[0053] Among them, the preparation method of the polyoxyethylene ether containing an azobenzene structure includes: mixing 4 - hydroxyazobenzene and sodium metal in toluene, stirring at 70 °C for 2 h under nitrogen protection to generate a sodium salt active intermediate; transferring the active intermediate to a high - pressure autoclave, slowly introducing ethylene oxide, controlling the temperature at 100 °C and the pressure at 0.5 MPa, reacting for 3 h, adding glacial acetic acid to neutralize to neutrality, and filtering to obtain it; the weight - part ratio of 4 - hydroxyazobenzene, sodium metal and toluene is 5:0.1:100, and the molar ratio of the active intermediate and ethylene oxide is 1:15.

[0054] The preparation method of this polyurethane foam stabilizer includes the steps of mixing polyether - modified polysiloxane, polyoxyethylene ether containing a furan ring, and azobenzene polyoxyethylene ether in proportion to obtain a mixed material, and adding 0.5% of triethylamine relative to the weight of the mixed material, and stirring at 60 °C for 2 h to obtain it.

[0055] Example 3

[0056] In this example, a polyurethane foam stabilizer is provided, which includes the following raw materials in parts by weight:

[0057] 70 parts of polyether - modified polysiloxane, prepared by hydrosilylation reaction of isocyanate - terminated unsaturated polyether and low hydrogen - containing silicone oil;

[0058] 30 parts of auxiliary stabilizing component, which is a polyoxyethylene ether containing a furan ring and has a number average molecular weight of 5000;

[0059] 10 parts of functional additive, which is a polyoxyethylene ether containing an azobenzene structure and has a number average molecular weight of 2000;

[0060] Among them, the preparation method of the polyether-modified polysiloxane includes:

[0061] (1) Preparation of isocyanate-terminated unsaturated polyether: Allyl alcohol, ethylene oxide, and propylene oxide are reacted in a proportion under the conditions of a basic catalyst sodium hydroxide, a temperature of 120 °C, and a pressure of 0.5 MPa to obtain an allyl-terminated polyether; toluene diisocyanate is added for a capping reaction, the reaction temperature is 80 °C, and the time is 4 hours to generate an isocyanate-terminated polyether; the weight part ratio of allyl alcohol, ethylene oxide, propylene oxide, basic catalyst, and toluene diisocyanate is 8:20:60:1.5:12;

[0062] (2) Preparation of low-hydrogen-content silicone oil: Octamethylcyclotetrasiloxane, hexamethyldisiloxane, and a hydrogen-containing silicone oil with a hydrogen content ≥ 1% are reacted under the catalysis of an acidic ion exchange resin at a temperature of 70 °C for 5 hours to obtain a low-hydrogen-content silicone oil with a hydrogen content of 0.8%; the weight part ratio of octamethylcyclotetrasiloxane, hexamethyldisiloxane, hydrogen-containing silicone oil, and acidic ion exchange resin catalysis is 85:15:10:3; the acidic ion exchange resin is Amberlyst 35;

[0063] (3) Hydrosilylation: The isocyanate-terminated unsaturated polyether and the low-hydrogen-content silicone oil are mixed in a mass ratio of 6:1, and a chloroplatinic acid catalyst accounting for 0.21% of the total material weight part is added, and the reaction is carried out at 100 °C for 4 hours to generate a polyether-modified polysiloxane;

[0064] Among them, the preparation method of the polyoxyethylene ether containing a furan ring includes: Furfuralamine and methyl acrylate are added to ethanol, and under nitrogen protection, the temperature is raised to 70 °C, tetrabutylammonium bromide is added dropwise and reacted for 6 hours, and ethanol is removed by vacuum distillation to obtain a furan-acrylate intermediate. The above intermediate and ethylene oxide are put into a high-pressure reaction kettle in a molar ratio of 1:30, and a KOH catalyst accounting for 0.3% of the total material weight part is added; the temperature is gradually raised to 140 °C, the pressure is controlled at 0.7 MPa, and the reaction is carried out for 8 hours; after neutralization and filtration, dehydration with molecular sieves is carried out to obtain it; the weight part ratio of furfuralamine, methyl acrylate, ethanol, and tetrabutylammonium bromide is 15:90:320:0.3.

[0065] Among them, the preparation method of the polyoxyethylene ether containing azobenzene structure includes: mixing 4-hydroxyazobenzene with metallic sodium in toluene, stirring at 80 °C for 3 h under nitrogen protection to generate a sodium salt active intermediate; transferring the active intermediate to an autoclave, slowly introducing ethylene oxide, controlling the temperature at 110 °C and the pressure at 0.5 MPa, reacting for 4 hours, adding glacial acetic acid to neutralize to neutrality, and filtering to obtain; the weight part ratio of 4-hydroxyazobenzene, metallic sodium and toluene is 8:0.3:100, and the molar ratio of the active intermediate and ethylene oxide is 1:20.

[0066] The preparation method of this polyurethane foam stabilizer includes the steps of mixing a polyether-modified polysiloxane, a polyoxyethylene ether containing a furan ring, and an azobenzene polyoxyethylene ether in proportion to obtain a mixed material, adding triethylamine accounting for 1% by weight of the mixed material, and stirring at 70 °C for 3 hours to obtain.

[0067] Example 4

[0068] In this example, a polyurethane foam stabilizer is provided, including the following raw materials in parts by weight:

[0069] 50 parts of polyether-modified polysiloxane, prepared by hydrosilylation reaction of an isocyanate-terminated unsaturated polyether and a low hydrogen content silicone oil;

[0070] 30 parts of auxiliary stabilizing component, which is a polyoxyethylene ether containing a furan ring, with a number average molecular weight of 3000;

[0071] 5 parts of functional additive, which is a polyoxyethylene ether containing an azobenzene structure, with a number average molecular weight of 2000;

[0072] Among them, the preparation method of the polyether-modified polysiloxane includes:

[0073] (1) Preparation of isocyanate-terminated unsaturated polyether: Reacting allyl alcohol, ethylene oxide, and propylene oxide in proportion under the conditions of a basic catalyst sodium hydroxide, a temperature of 90 °C, and a pressure of 0.5 MPa to obtain an allyl-terminated polyether; adding toluene diisocyanate for end-capping reaction, with a reaction temperature of 80 °C and a time of 2 hours to generate an isocyanate-terminated polyether; the weight part ratio of allyl alcohol, ethylene oxide, propylene oxide, basic catalyst, and toluene diisocyanate is 8:15:60:1.5:12;

[0074] (2) Preparation of low hydrogen - containing silicone oil: Octamethylcyclotetrasiloxane, hexamethyldisiloxane and hydrogen - containing silicone oil with a hydrogen content ≥ 1% are reacted under the catalysis of acidic ion - exchange resin at a temperature of 70 °C for 3 h to obtain low hydrogen - containing silicone oil with a hydrogen content of 0.8%; the weight - part ratio of octamethylcyclotetrasiloxane, hexamethyldisiloxane, hydrogen - containing silicone oil and acidic ion - exchange resin catalysis is 70:10:10:3; the acidic ion - exchange resin is Amberlyst 15;

[0075] (3) Hydrosilylation: The isocyanate - terminated unsaturated polyether and low hydrogen - containing silicone oil are mixed at a mass ratio of 4:1, and a chloroplatinic acid catalyst accounting for 0.21% of the total material weight is added, and the reaction is carried out at 100 °C for 4 h to generate polyether - modified polysiloxane;

[0076] Among them, the preparation method of the polyoxyethylene ether containing a furan ring includes: Furfuralamine and methyl acrylate are added to ethanol, and under nitrogen protection, the temperature is raised to 60 °C, tetrabutylammonium bromide is added dropwise and reacted for 6 hours, and after ethanol is removed by vacuum distillation, a furan - acrylate intermediate is obtained. The above intermediate and ethylene oxide are put into a high - pressure reactor at a molar ratio of 1:25, and a KOH catalyst accounting for 0.3% of the total material weight is added; the temperature is gradually raised to 140 °C, the pressure is controlled at 0.8 MPa, and the reaction is carried out for 8 hours; after neutralization, filtration is carried out, and dehydration with molecular sieve is carried out to obtain it; the weight - part ratio of furfuralamine, methyl acrylate, ethanol and tetrabutylammonium bromide is 15:85:320:0.2.

[0077] Among them, the preparation method of the polyoxyethylene ether containing an azobenzene structure includes: 4 - hydroxyazobenzene and sodium metal are mixed in toluene, and stirred at 70 °C for 3 h under nitrogen protection to generate a sodium salt active intermediate; the active intermediate is transferred to a high - pressure autoclave, ethylene oxide is slowly introduced, the temperature is controlled at 100 °C, the pressure is 0.5 MPa, and the reaction is carried out for 4 hours. After adding glacial acetic acid to neutralize to neutrality, filtration is carried out to obtain it; the weight - part ratio of 4 - hydroxyazobenzene, sodium metal and toluene is 5:0.3:100, and the molar ratio of the active intermediate and ethylene oxide is 1:20.

[0078] The preparation method of this polyurethane foam stabilizer includes the steps of mixing polyether - modified polysiloxane, polyoxyethylene ether containing a furan ring, and azobenzene polyoxyethylene ether in proportion to obtain a mixed material, adding triethylamine accounting for 0.5% of the weight of the mixed material, and stirring at 70 °C for 2 hours to obtain it.

[0079] Comparative Example 1

[0080] Based on Example 1 for adjustment, different from Example 1, in Comparative Example 1, the polyether - modified polysiloxane is replaced with ordinary polydimethylsiloxane, CAS number: 156327 - 07 - 0, model: P433351 (Aladdin Reagent Co., Ltd.).

[0081] Comparative Example 2

[0082] Based on Example 1 with adjustments, different from Example 1, in Comparative Example 2, the auxiliary stabilizing component was replaced with a common polyoxyethylene ether having a number-average molecular weight of 4000.

[0083] Comparative Example 3

[0084] Based on Example 1 with adjustments, different from Example 1, in Comparative Example 3, the auxiliary stabilizing component was removed, and the other components were the same as in Example 1.

[0085] Comparative Example 4

[0086] Based on Example 1 with adjustments, different from Example 1, in Comparative Example 4, the functional additive was replaced with a common polyoxyethylene ether having a number-average molecular weight of 4000.

[0087] Comparative Example 5

[0088] Based on Example 1 with adjustments, different from Example 1, in Comparative Example 5, the functional additive was removed, and the other components were the same as in Example 1.

[0089] Comparative Example 6

[0090] Based on Example 1 with adjustments, different from Example 1, in Comparative Example 6, both the auxiliary stabilizing component and the functional additive were replaced with a common polyoxyethylene ether having a number-average molecular weight of 4000.

[0091] The performance of the polyurethane foams prepared in Examples 1 - 4 and Comparative Examples 1 - 6 was tested as follows:

[0092] The polyurethane foam was prepared through the following polyurethane foaming formulation by weight ratio: 80 parts of polyether polyol 4110 (Xuzhou Yihuiyang New Materials Co., Ltd.), 20 parts of polyether polyol 635 (Langfang Huayu Innovation Technology Co., Ltd.), 1.5 parts of water, 1.3 parts of DMP30, 1.5 parts of foam stabilizer, 13 parts of cyclopentane, and 143 parts of MDI; the foam stabilizer was the polyurethane foam stabilizer prepared in the examples and comparative examples.

[0093] Thermal conductivity: The above formulation was mixed and injected into a mold of 1100×300×50 through a high-pressure foaming machine for closed-mold foaming, and the foam core density was 30 kg / m 3 , and it was measured with a thermal conductivity measuring device based on JIS A1412.

[0094] Stability performance: The above formulation was mixed and left standing, and whether there was stratification or turbidity in the solution state was counted, and timing was carried out. Five groups were counted for each group and the average value was taken.

[0095] The test results are shown in Table 1.

[0096] Table 1 Test Results

[0097]

[0098] According to the above content, after using ordinary polydimethylsiloxane in Comparative Example 1, the thermal conductivity increased by 13.6% and the emulsification time was shortened by 52.2%, indicating that the polyether-modified structure capped with isocyanate significantly improved the interfacial compatibility and cell uniformity. In Comparative Example 2, the thermal conductivity increased by 10.8% and the emulsification time was shortened by 30.2%; in Comparative Example 3, the thermal conductivity increased by 18.2% and the emulsification time was shortened by 64.9%, indicating that the polyoxyethylene ether containing a furan ring strengthened the intermolecular crosslinking network through π-π interactions. In Comparative Example 4, the thermal conductivity increased by 8.5% and the emulsification time was shortened by 18.5%; in Comparative Example 5, the thermal conductivity increased by 14.2% and the emulsification time was shortened by 39.5%, proving that the photo-responsive property of the azobenzene group can dynamically regulate the cell structure. In Comparative Example 6, the thermal conductivity increased by 29.0% and the emulsification time was shortened by 72.7%, verifying the synergistic effect of the ternary system, where the polyether-modified polysiloxane provides the main chain flexibility, the furan ring auxiliary component enhances the thermal stability, and the azobenzene additive realizes the dynamic regulation of the cells.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the present invention and do not limit the technical solutions described in the present invention; those of ordinary skill in the art should understand that the present invention can still be modified or equivalently replaced; and all technical solutions and their improvements that do not depart from the spirit and scope of the present invention should be covered by the scope of the claims of the present invention.

Claims

1. A polyurethane foam stabilizer, characterized in that It includes the following raw materials in parts by weight: 50-70 parts of polyether-modified polysiloxane, prepared by hydrosilylation reaction of isocyanate-terminated unsaturated polyether and low-hydrogen silicone oil; 20-30 parts of auxiliary stabilizing component, which is polyoxyethylene ether containing furan ring and has a number average molecular weight of 3000-5000; The functional additive is 5-10 parts, which is a polyoxyethylene ether containing an azobenzene structure and has a number average molecular weight of 1000-2000.

2. A polyurethane foam stabilizer according to claim 1, characterized in that: The preparation method of the polyether-modified polysiloxane comprises: (1) Preparation of isocyanate-terminated unsaturated polyether: allyl alcohol, ethylene oxide and propylene oxide are reacted in proportion under an alkaline catalyst to obtain an allyl-terminated polyether; toluene diisocyanate is added to carry out a capping reaction to generate an isocyanate-terminated polyether; (2) Preparation of low hydrogen silicone oil: Octamethylcyclotetrasiloxane, hexamethyldisiloxane and hydrogen silicone oil with a hydrogen content of ≥1% are reacted under the catalysis of an acidic ion exchange resin to obtain low hydrogen silicone oil; (3) Hydrosilylation: Mix the isocyanate-terminated unsaturated polyether and low-hydrogen silicone oil in a mass ratio of 4-6:1, add chloroplatinic acid catalyst to react, and generate polyether-modified polysiloxane.

3. A polyurethane foam stabilizer according to claim 2, characterized in that: The weight ratio of allyl alcohol, ethylene oxide, propylene oxide, alkaline catalyst and toluene diisocyanate is (5-8): (15-20): (45-60): (0.5-1.5): (8-12).

4. A polyurethane foam stabilizer according to claim 2, characterized in that: The weight ratio of octamethylcyclotetrasiloxane, hexamethyldisiloxane, hydrogenated silicone oil and acidic ion exchange resin catalyst is (70-85): (10-15): (5-10): (2-3).

5. A polyurethane foam stabilizer according to claim 2, characterized in that: The acidic ion exchange resin includes any one of Amberlyst 15, Amberlyst 35 and D001.

6. A polyurethane foam stabilizer according to claim 1, characterized in that: The preparation method of the furan ring-containing polyoxyethylene ether comprises: adding furfurylamine and methyl acrylate into ethanol, heating to 60-70°C under nitrogen protection, dropping tetrabutylammonium bromide for reaction for 4-6 hours, removing ethanol by reduced pressure distillation to obtain a furan-acrylate intermediate, adding the intermediate and ethylene oxide in a 1:25-30 molar ratio into a high-pressure reactor, adding a catalyst for reaction, filtering after neutralization, and dehydrating with a molecular sieve to obtain the polyoxyethylene ether.

7. A polyurethane foam stabilizer according to claim 6, characterized in that: The weight ratio of furfurylamine, methyl acrylate, ethanol and tetrabutylammonium bromide is (10-15): (85-90): (280-320): (0.2-0.3).

8. A polyurethane foam stabilizer according to claim 1, characterized in that: The preparation method of the polyoxyethylene ether containing an azobenzene structure comprises: mixing 4-hydroxyazobenzene and metallic sodium in toluene, stirring at 70-80° C. for 2-3 hours under nitrogen protection to generate a sodium salt active intermediate; transferring the active intermediate to an autoclave, slowly introducing ethylene oxide, controlling the temperature at 100-110° C. and the pressure at ≤0.5 MPa, reacting for 3-4 hours, adding glacial acetic acid to neutralize to neutrality, and filtering to obtain the polyoxyethylene ether.

9. A polyurethane foam stabilizer according to claim 8, characterized in that: The weight ratio of the 4-hydroxyazobenzene, metallic sodium and toluene is (5-8):(0.1-0.3):100, and the molar ratio of the active intermediate to ethylene oxide is 1:15-20.

10. A method for preparing the polyurethane foam stabilizer according to any one of claims 1 to 9, characterized in that: The steps include mixing polyether-modified polysiloxane, polyoxyethylene ether containing furan ring and azobenzene polyoxyethylene ether in proportion to obtain a mixture, adding 0.5-1% of triethylamine relative to the weight of the mixture, and stirring at 60-70°C for 2-3 hours to obtain the mixture.

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