Polyurethane foam for thermal insulation strips and method for the production thereof

Abstract

This invention relates to the field of polyurethane foam preparation technology, and discloses a polyurethane foam for thermal insulation strips and its preparation method. The polyurethane foam comprises the following raw materials in parts by weight: 40-60 parts of polytetrahydrofuran ether diol, 10-15 parts of modified monomer, 1-5 parts of ethylenediamine, 1-5 parts of hydroxyethyl methacrylate, 60-80 parts of diphenylmethane diisocyanate, 3-5 parts of modified filler, 0.3-0.5 parts of benzophenone, and 10-15 parts of n-pentane. After hot pressing and foaming of the raw materials, and then treatment with ultraviolet light, the double bonds on the hydroxyethyl methacrylate can react with the mercapto groups on the surface of the modified filler, thereby forming a cross-linked network in the material. By restricting the movement of molecular chains, reducing gas diffusion and heat conduction paths, the cell structure becomes more uniform and stable. Combined with the multi-layered hollow structure of the modified filler, the closed-cell rate of the foam can be improved, gas diffusion can be reduced, thereby maintaining a long-term stable thermal insulation effect.

Description

Technical Field

[0001] This invention relates to the field of polyurethane foam preparation technology, specifically to a polyurethane foam for thermal insulation strips and its preparation method. Background Technology

[0002] Polyurethane foam, a commonly used thermal insulation material, is widely used in the construction and industrial sectors. It features lightweight construction, good compression resilience, excellent thermal and sound insulation, high chemical stability, a certain degree of thermal insulation, and sealing performance, effectively preventing air penetration through windows and door frames, thus improving the building's thermal insulation performance. However, in traditional building structures, due to sealing issues in windows and door frames, heat can still easily escape through gaps, reducing the overall insulation effect. Therefore, there is an urgent need for a higher-performance thermal insulation material to overcome the shortcomings of traditional materials. Summary of the Invention

[0003] The purpose of this invention is to provide a polyurethane foam for thermal insulation strips and its preparation method, which solves the problem of limited thermal insulation effect of current thermal insulation foams.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] A method for preparing polyurethane foam for thermal insulation strips specifically includes the following steps:

[0006] Step A1: Mix ethylenediamine, 3,4-epoxy-1-butene, and DMF evenly and react for 6-8 hours at a speed of 120-150 r / min, a temperature of 40-50℃, and a pH of 10-11 to obtain an intermediate. Mix lithium trimethylsilanolate and tetrahydrofuran evenly and stir at a speed of 150-200 r / min and a temperature of 0℃. Add trifluoropropylmethylcyclotrisiloxane, raise the temperature to 25-30℃, and react for 7-9 hours. Then add trichlorosilane and continue the reaction for 1-1.5 hours to obtain the modifier.

[0007] Step A2: Mix the intermediate, modifier, chloroplatinic acid and DMF evenly, purge with nitrogen, and react for 6-8 hours at a speed of 200-300 r / min and a temperature of 75-85℃ to obtain the modified monomer.

[0008] Step A3: Weigh the following raw materials in parts by weight: 40-60 parts of polytetrahydrofuran ether diol, 10-15 parts of modified monomer, 1-5 parts of ethylenediamine, 1-5 parts of hydroxyethyl methacrylate, 60-80 parts of diphenylmethane diisocyanate, 3-5 parts of modified filler, 0.3-0.5 parts of benzophenone, and 10-15 parts of n-pentane. Mix the raw materials evenly, add them to a mold, hot press and foam, and then treat with ultraviolet light for 10-15 seconds to obtain polyurethane foam for thermal insulation strips.

[0009] Furthermore, the molar ratio of ethylenediamine and 3,4-epoxy-1-butene in step A1 is 1:4, and the molar ratio of Si-Cl on lithium trimethylsilanolate, trifluoropropylmethylcyclotrisiloxane and trichlorosilane is 1:3:1.

[0010] Furthermore, the molar ratio of the intermediate and the modifier in step A2 is 1:4, and the amount of chloroplatinic acid used is 3‰ of the mass of the intermediate.

[0011] Furthermore, the modified filler is prepared by the following steps:

[0012] Step B1: Styrene, deionized water and polyvinylpyrrolidone are mixed evenly. Under the conditions of 120-150 r / min and 80-90℃, ammonium persulfate is added and the mixture is stirred for 8-10 h to obtain a seed emulsion. The seed emulsion, ammonia and ethanol are mixed evenly. Under the conditions of 200-300 r / min and 70-80℃, tetraethyl orthosilicate is added and the mixture is stirred for 10-15 h to obtain hollow nanospheres.

[0013] Step B2: Disperse hollow nanospheres in ethanol, stir and add deionized water and γ-aminopropyltriethoxysilane at a speed of 200-300 r / min and a temperature of 70-75℃, and react for 3-5 h to obtain aminated microspheres. Disperse the aminated microspheres in toluene, purge with nitrogen, stir and add propyltriethoxysilane at a speed of 300-500 r / min and a temperature of 30-40℃, and react for 2-3 h to obtain functionalized microspheres.

[0014] Step B3: Mix functionalized microspheres, methyltriethoxysilane and ethanol evenly. Stir and add deionized water and hydrochloric acid at a speed of 200-300 r / min and a temperature of 65-70℃. After reacting for 1-1.5 h, add tetrabutyl titanate and continue reacting for 2-3 h. Raise the temperature to 120-125℃ and continue reacting for 2-3 h to obtain pretreated microspheres.

[0015] Step B4: Mix the pretreated microspheres, tetraethyl orthosilicate, 3-mercaptopropyltrimethoxysilane and ethanol evenly. React for 30-40 minutes at a rotation speed of 300-500 r / min, a temperature of 40-50℃ and a pH of 2-3. Then adjust the pH to 5-6, raise the temperature to 70-80℃ and continue the reaction for 2-3 hours. Finally, age for 12-15 hours to obtain the modified filler.

[0016] Furthermore, in step B1, the ratio of styrene, deionized water, and polyvinylpyrrolidone is 5 mL:45 mL:0.8 g, the polyvinylpyrrolidone is of type K30, the volume ratio of seed emulsion, ammonia, ethanol, and tetraethyl orthosilicate is 3:0.6:60:5, and the mass fraction of ammonia is 25%.

[0017] Furthermore, the amount of γ-aminopropyltriethoxysilane used in step B2 is 3% of the mass of the hollow nanospheres, and the molar ratio of the amino group on the aminated microspheres to propyltriethoxysilane is 1:1.

[0018] Furthermore, the ratio of the functionalized microspheres, methyltriethoxysilane, ethanol, deionized water, hydrochloric acid, and tetrabutyl titanate in step B3 is 1g:14mmol:40mL:3mL:1mL:4mmol.

[0019] Furthermore, the ratio of the pretreated microspheres, tetraethyl orthosilicate, 3-mercaptopropyltrimethoxysilane, and ethanol used in step B4 is 1g:2g:0.2g:30mL.

[0020] The beneficial effects of this invention are as follows: A polyurethane foam for thermal insulation strips disclosed in this application comprises the following raw materials: polytetrahydrofuran ether diol, modified monomer, ethylenediamine, hydroxyethyl methacrylate, diphenylmethane diisocyanate, modified filler, and n-pentane. The modified monomer is prepared by reacting ethylenediamine and 3,4-epoxy-1-butene as raw materials, so that the amino group on the ethylenediamine reacts with the epoxy group on the 3,4-epoxy-1-butene to obtain an intermediate. Trimethylsilyl alcohol is used as an initiator, trifluoropropylmethylcyclotrisiloxane is used as a polymerization monomer, and trichlorosilane is added to react the Si-Cl bond on the trichlorosilane with the lithium silyl alcohol to obtain a modifier. The intermediate and the modifier are reacted to react the double bond on the intermediate with the Si-H bond on the modifier to obtain the modified monomer.

[0021] Modified fillers were prepared by emulsion polymerization of polyvinylpyrrolidone-functionalized polystyrene latex using styrene as a raw material. Seed emulsions were obtained, and hollow nanospheres were synthesized in a one-step process by coating the polystyrene template particles with silica while simultaneously dissolving them in an ammonia-alcohol medium. The hollow nanospheres were then treated with γ-aminopropyltriethoxysilane to graft amino groups onto their surface, yielding aminated microspheres. These aminated microspheres were then treated with propyltriethoxysilane isocyanate to further enhance their aminated properties. The amino groups on the surface of the microspheres react with the isocyanate groups on propyltriethoxysilane to prepare functionalized microspheres. The functionalized microspheres, tetraethyl orthosilicate, and 3-mercaptopropyltrimethoxysilane are mixed and hydrolyzed and condensed, and then tetrabutyl titanate is added and hydrolyzed and condensed to form titanium-doped silica coating on the surface of the functionalized microspheres, thus obtaining pretreated microspheres. The pretreated microspheres, tetraethyl orthosilicate, and 3-mercaptopropyltrimethoxysilane are mixed and hydrolyzed to form thiol-containing silica coating on the surface of the pretreated microspheres, thus obtaining modified fillers.

[0022] After hot-pressing and foaming of the raw material, followed by ultraviolet irradiation treatment, the double bonds on hydroxyethyl methacrylate can react with the thiol groups on the surface of the modified filler, thereby forming a cross-linked network in the material. By restricting molecular chain movement, reducing gas diffusion and heat conduction paths, the cell structure becomes more uniform and stable. Combined with the multi-layered hollow structure of the modified filler, it can improve the closed-cell rate of the foam, reduce gas diffusion, and thus maintain a long-term stable thermal insulation effect. Furthermore, the polysiloxane segments and long-chain fluoroalkane on the modified monomer can reduce the water absorption of the foam, further extending the service life of the material. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1: A method for preparing polyurethane foam for thermal insulation strips, specifically including the following steps:

[0025] Step A1: Ethylenediamine, 3,4-epoxy-1-butene, and DMF were mixed evenly and reacted for 6 hours at a speed of 120 r / min, a temperature of 40 °C, and a pH of 10 to obtain an intermediate. Lithium trimethylsilanolate and tetrahydrofuran were mixed evenly and stirred at a speed of 150 r / min and a temperature of 0 °C. Trifluoropropylmethylcyclotrisiloxane was added, the temperature was raised to 25 °C, and the reaction was carried out for 7 hours. Trichlorosilane was then added, and the reaction was continued for 1 hour to obtain the modifier.

[0026] Step A2: Mix the intermediate, modifier, chloroplatinic acid and DMF evenly, purge with nitrogen, and react for 6 hours at a speed of 200 r / min and a temperature of 75℃ to obtain the modified monomer.

[0027] Step A3: Weigh the following raw materials in parts by weight: 40 parts polytetrahydrofuran ether diol, 10 parts modified monomer, 1 part ethylenediamine, 1 part hydroxyethyl methacrylate, 60 parts diphenylmethane diisocyanate, 3 parts modified filler, 0.3 parts benzophenone, and 10 parts n-pentane. Mix the raw materials evenly and add them to the mold. Under the conditions of 60℃ and 0.3MPa, hot press for 2 minutes, and then irradiate with ultraviolet light for 10 seconds to obtain polyurethane foam for thermal insulation strips.

[0028] The molar ratio of ethylenediamine and 3,4-epoxy-1-butene in step A1 is 1:4, and the molar ratio of Si-Cl on lithium trimethylsilanolate, trifluoropropylmethylcyclotrisiloxane and trichlorosilane is 1:3:1.

[0029] The molar ratio of the intermediate and the modifier mentioned in step A2 is 1:4, and the amount of chloroplatinic acid used is 3‰ of the mass of the intermediate.

[0030] The polytetrahydrofuran ether diol mentioned in step A3 has a molecular weight of 2000.

[0031] The modified filler is prepared by the following steps:

[0032] Step B1: Styrene, deionized water and polyvinylpyrrolidone are mixed evenly, stirred and ammonium persulfate is added at 120 r / min and 80 ℃, and the reaction is carried out for 8 h to obtain seed emulsion. Seed emulsion, ammonia and ethanol are mixed evenly, stirred and tetraethyl orthosilicate is added at 200 r / min and 70 ℃, and the reaction is carried out for 10 h to obtain hollow nanospheres.

[0033] Step B2: Hollow nanospheres were dispersed in ethanol, stirred at 200 r / min and 70 °C, and deionized water and γ-aminopropyltriethoxysilane were added. The reaction was carried out for 3 h to obtain aminated microspheres. The aminated microspheres were dispersed in toluene, protected by nitrogen gas, stirred at 300 r / min and 30 °C, and propyltriethoxysilane was added. The reaction was carried out for 2 h to obtain functionalized microspheres.

[0034] Step B3: Mix functionalized microspheres, methyltriethoxysilane and ethanol evenly. Stir and add deionized water and hydrochloric acid at a speed of 200 r / min and a temperature of 65℃. After reacting for 1 h, add tetrabutyl titanate and continue reacting for 2 h. Raise the temperature to 120℃ and continue reacting for 2 h to obtain pretreated microspheres.

[0035] Step B4: Mix the pretreated microspheres, tetraethyl orthosilicate, 3-mercaptopropyltrimethoxysilane and ethanol evenly. React for 30 minutes at a speed of 300 r / min, a temperature of 40℃ and a pH of 2. Then adjust the pH to 5, raise the temperature to 70℃ and continue the reaction for 2 hours. Then age for 12 hours to obtain the modified filler.

[0036] The ratio of styrene, deionized water and polyvinylpyrrolidone used in step B1 is 5 mL:45 mL:0.8 g, the polyvinylpyrrolidone is of type K30, the volume ratio of seed emulsion, ammonia, ethanol and tetraethyl orthosilicate is 3:0.6:60:5, and the mass fraction of ammonia is 25%.

[0037] The amount of γ-aminopropyltriethoxysilane used in step B2 is 3% of the mass of the hollow nanospheres, and the molar ratio of the amino group on the aminated microspheres to propyltriethoxysilane is 1:1.

[0038] The ratio of functionalized microspheres, methyltriethoxysilane, ethanol, deionized water, hydrochloric acid and tetrabutyl titanate in step B3 is 1g:14mmol:40mL:3mL:1mL:4mmol.

[0039] The ratio of the pretreated microspheres, tetraethyl orthosilicate, 3-mercaptopropyltrimethoxysilane, and ethanol used in step B4 is 1g:2g:0.2g:30mL.

[0040] Example 2, a method for preparing polyurethane foam for thermal insulation strips, specifically includes the following steps:

[0041] Step A1: Ethylenediamine, 3,4-epoxy-1-butene, and DMF were mixed evenly and reacted for 7 hours at a speed of 120 r / min, a temperature of 45 °C, and a pH of 11 to obtain an intermediate. Lithium trimethylsilanolate and tetrahydrofuran were mixed evenly and stirred at a speed of 150 r / min and a temperature of 0 °C. Trifluoropropylmethylcyclotrisiloxane was added, the temperature was raised to 30 °C, and the reaction was carried out for 8 hours. Trichlorosilane was then added, and the reaction was continued for 1.3 hours to obtain the modifier.

[0042] Step A2: Mix the intermediate, modifier, chloroplatinic acid and DMF evenly, purge with nitrogen, and react for 7 hours at a speed of 200 r / min and a temperature of 80℃ to obtain the modified monomer.

[0043] Step A3: Weigh the following raw materials in parts by weight: 50 parts polytetrahydrofuran ether diol, 13 parts modified monomer, 3 parts ethylenediamine, 3 parts hydroxyethyl methacrylate, 70 parts diphenylmethane diisocyanate, 4 parts modified filler, 0.4 parts benzophenone, and 13 parts n-pentane. Mix the raw materials evenly and add them to the mold. Under the conditions of 60℃ and 0.3MPa, hot press for 2 minutes, and then irradiate with ultraviolet light for 13 seconds to obtain polyurethane foam for thermal insulation strips.

[0044] The molar ratio of ethylenediamine and 3,4-epoxy-1-butene in step A1 is 1:4, and the molar ratio of Si-Cl on lithium trimethylsilanolate, trifluoropropylmethylcyclotrisiloxane and trichlorosilane is 1:3:1.

[0045] The molar ratio of the intermediate and the modifier mentioned in step A2 is 1:4, and the amount of chloroplatinic acid used is 3‰ of the mass of the intermediate.

[0046] The polytetrahydrofuran ether diol mentioned in step A3 has a molecular weight of 2000.

[0047] The modified filler is prepared by the following steps:

[0048] Step B1: Styrene, deionized water and polyvinylpyrrolidone are mixed evenly, stirred and ammonium persulfate is added at 120 r / min and 85 ℃, and reacted for 9 h to obtain a seed emulsion. The seed emulsion, ammonia and ethanol are mixed evenly, stirred and tetraethyl orthosilicate is added at 300 r / min and 75 ℃, and reacted for 13 h to obtain hollow nanospheres.

[0049] Step B2: Hollow nanospheres were dispersed in ethanol, and under conditions of 200 r / min and 73 °C, deionized water and γ-aminopropyltriethoxysilane were added and the reaction was carried out for 4 h to obtain aminated microspheres. The aminated microspheres were then dispersed in toluene, and nitrogen gas was introduced for protection. Under conditions of 300 r / min and 35 °C, propyltriethoxysilane was added and the reaction was carried out for 3 h to obtain functionalized microspheres.

[0050] Step B3: Mix functionalized microspheres, methyltriethoxysilane and ethanol evenly. Stir and add deionized water and hydrochloric acid at a speed of 200 r / min and a temperature of 70℃. After reacting for 1.3 h, add tetrabutyl titanate and continue reacting for 2.5 h. Raise the temperature to 125℃ and continue reacting for 2 h to obtain pretreated microspheres.

[0051] Step B4: Mix the pretreated microspheres, tetraethyl orthosilicate, 3-mercaptopropyltrimethoxysilane and ethanol evenly. React for 35 minutes at a speed of 500 r / min, a temperature of 45℃ and a pH of 3. Then adjust the pH to 5, raise the temperature to 75℃ and continue the reaction for 3 hours. Then age for 12 hours to obtain the modified filler.

[0052] The ratio of styrene, deionized water and polyvinylpyrrolidone used in step B1 is 5 mL:45 mL:0.8 g, the polyvinylpyrrolidone is of type K30, the volume ratio of seed emulsion, ammonia, ethanol and tetraethyl orthosilicate is 3:0.6:60:5, and the mass fraction of ammonia is 25%.

[0053] The amount of γ-aminopropyltriethoxysilane used in step B2 is 3% of the mass of the hollow nanospheres, and the molar ratio of the amino group on the aminated microspheres to propyltriethoxysilane is 1:1.

[0054] The ratio of functionalized microspheres, methyltriethoxysilane, ethanol, deionized water, hydrochloric acid and tetrabutyl titanate in step B3 is 1g:14mmol:40mL:3mL:1mL:4mmol.

[0055] The ratio of the pretreated microspheres, tetraethyl orthosilicate, 3-mercaptopropyltrimethoxysilane, and ethanol used in step B4 is 1g:2g:0.2g:30mL.

[0056] Example 3, a method for preparing polyurethane foam for thermal insulation strips, specifically includes the following steps:

[0057] Step A1: Ethylenediamine, 3,4-epoxy-1-butene, and DMF were mixed evenly and reacted for 8 hours at a speed of 150 r / min, a temperature of 50 °C, and a pH of 11 to obtain an intermediate. Lithium trimethylsilanolate and tetrahydrofuran were mixed evenly and stirred at a speed of 200 r / min and a temperature of 0 °C. Trifluoropropylmethylcyclotrisiloxane was added, the temperature was raised to 30 °C, and the reaction was carried out for 9 hours. Trichlorosilane was then added, and the reaction was continued for 1.5 hours to obtain the modifier.

[0058] Step A2: Mix the intermediate, modifier, chloroplatinic acid and DMF evenly, purge with nitrogen, and react for 8 hours at a speed of 300 r / min and a temperature of 85℃ to obtain the modified monomer.

[0059] Step A3: Weigh the following raw materials in parts by weight: 60 parts polytetrahydrofuran ether diol, 15 parts modified monomer, 5 parts ethylenediamine, 5 parts hydroxyethyl methacrylate, 80 parts diphenylmethane diisocyanate, 5 parts modified filler, 0.5 parts benzophenone, and 15 parts n-pentane. Mix the raw materials evenly and add them to the mold. Under the conditions of 60℃ and 0.3MPa, hot press for 2 minutes, and then irradiate with ultraviolet light for 15 seconds to obtain polyurethane foam for thermal insulation strips.

[0060] The molar ratio of ethylenediamine and 3,4-epoxy-1-butene in step A1 is 1:4, and the molar ratio of Si-Cl on lithium trimethylsilanolate, trifluoropropylmethylcyclotrisiloxane and trichlorosilane is 1:3:1.

[0061] The molar ratio of the intermediate and the modifier mentioned in step A2 is 1:4, and the amount of chloroplatinic acid used is 3‰ of the mass of the intermediate.

[0062] The polytetrahydrofuran ether diol mentioned in step A3 has a molecular weight of 2000.

[0063] The modified filler is prepared by the following steps:

[0064] Step B1: Styrene, deionized water and polyvinylpyrrolidone are mixed evenly, stirred and ammonium persulfate is added at 150 r / min and 90 ℃, and reacted for 10 h to obtain a seed emulsion. The seed emulsion, ammonia and ethanol are mixed evenly, stirred and tetraethyl orthosilicate is added at 300 r / min and 80 ℃, and reacted for 15 h to obtain hollow nanospheres.

[0065] Step B2: Hollow nanospheres were dispersed in ethanol, stirred at 300 r / min and 75 °C, and deionized water and γ-aminopropyltriethoxysilane were added. The reaction was carried out for 5 h to obtain aminated microspheres. The aminated microspheres were dispersed in toluene, protected by nitrogen gas, stirred at 500 r / min and 40 °C, and propyltriethoxysilane was added. The reaction was carried out for 3 h to obtain functionalized microspheres.

[0066] Step B3: Mix functionalized microspheres, methyltriethoxysilane and ethanol evenly. Stir and add deionized water and hydrochloric acid at a speed of 300 r / min and a temperature of 70°C. After reacting for 1.5 h, add tetrabutyl titanate and continue reacting for 3 h. Raise the temperature to 125°C and continue reacting for 3 h to obtain pretreated microspheres.

[0067] Step B4: Mix the pretreated microspheres, tetraethyl orthosilicate, 3-mercaptopropyltrimethoxysilane and ethanol evenly. React for 40 minutes at a speed of 500 r / min, a temperature of 50℃ and a pH of 3. Then adjust the pH to 6, raise the temperature to 80℃ and continue the reaction for 3 hours. Then age for 15 hours to obtain the modified filler.

[0068] The ratio of styrene, deionized water and polyvinylpyrrolidone used in step B1 is 5 mL:45 mL:0.8 g, the polyvinylpyrrolidone is of type K30, the volume ratio of seed emulsion, ammonia, ethanol and tetraethyl orthosilicate is 3:0.6:60:5, and the mass fraction of ammonia is 25%.

[0069] The amount of γ-aminopropyltriethoxysilane used in step B2 is 3% of the mass of the hollow nanospheres, and the molar ratio of the amino group on the aminated microspheres to propyltriethoxysilane is 1:1.

[0070] The ratio of functionalized microspheres, methyltriethoxysilane, ethanol, deionized water, hydrochloric acid and tetrabutyl titanate in step B3 is 1g:14mmol:40mL:3mL:1mL:4mmol.

[0071] The ratio of the pretreated microspheres, tetraethyl orthosilicate, 3-mercaptopropyltrimethoxysilane, and ethanol used in step B4 is 1g:2g:0.2g:30mL.

[0072] Comparative Example 1: This comparative example did not include any modified monomers compared to Example 1, but the remaining steps were the same.

[0073] Comparative Example 2: This comparative example uses hollow nanospheres instead of modified fillers, but the other steps are the same as in Example 1.

[0074] Comparative Example 3: This comparative example uses pretreated microspheres instead of modified fillers, but the other steps are the same as in Example 1.

[0075] Comparative Example 4: This comparative example did not include 3-mercaptopropyltrimethoxysilane compared to Example 1, but the remaining steps were the same.

[0076] The polyurethane foams obtained in Examples 1-3 and Comparative Examples 1-4 were made into plate-shaped containers with a thickness of 30 mm. The plate-shaped containers were placed on a heat source, and the heat source was sealed on all sides. The heat source was then turned off, and the temperature of the side of the plate-shaped container away from the heat source was measured. The temperature of the heat source was controlled at 250 °C. The temperature of the side of the plate-shaped container away from the heat source was measured after 30 min, 1 h, and 2 h, and the temperature difference was calculated. The test results are shown in Table 1 below.

[0077] Table 1

[0078]

[0079] As shown in Table 1, this application has excellent heat insulation effect.

[0080] The above description is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing polyurethane foam for thermal insulation strips, characterized in that: Specifically, the steps include the following: Step A1: Mix ethylenediamine, 3,4-epoxy-1-butene and DMF to prepare an intermediate. Mix lithium trimethylsilanolate and tetrahydrofuran and add trifluoropropylmethylcyclotrisiloxane. After reaction, add trichlorosilane and continue the reaction to obtain the modifier. Step A2: Mix the intermediate, modifier, chloroplatinic acid and DMF evenly, purge with nitrogen gas for protection, and carry out the reaction to obtain the modified monomer; Step A3: Weigh the following raw materials in parts by weight: 40-60 parts of polytetrahydrofuran ether diol, 10-15 parts of modified monomer, 1-5 parts of ethylenediamine, 1-5 parts of hydroxyethyl methacrylate, 60-80 parts of diphenylmethane diisocyanate, 3-5 parts of modified filler, 0.3-0.5 parts of benzophenone, and 10-15 parts of n-pentane. Mix the raw materials evenly, add them to a mold, hot press and foam, and then treat with ultraviolet light to obtain polyurethane foam for thermal insulation strips. The modified filler is prepared by the following steps: Step B1: Styrene, deionized water and polyvinylpyrrolidone are mixed and stirred and ammonium persulfate is added to react and obtain seed emulsion. Seed emulsion, ammonia and ethanol are mixed and stirred and tetraethyl orthosilicate is added to react and obtain hollow nanospheres. Step B2: Disperse hollow nanospheres in ethanol, stir, and add deionized water and γ-aminopropyltriethoxysilane to react and obtain aminated microspheres. Disperse the aminated microspheres in toluene, purge with nitrogen, stir, and add propyltriethoxysilane isocyanate to react for 2-3 hours to obtain functionalized microspheres. Step B3: Functionalized microspheres, methyltriethoxysilane and ethanol are mixed and stirred, and deionized water and hydrochloric acid are added. After the reaction, tetrabutyl titanate is added and the reaction is continued to obtain pretreated microspheres. Step B4: Mix and react the pretreated microspheres, tetraethyl orthosilicate, 3-mercaptopropyltrimethoxysilane and ethanol to obtain the modified filler.

2. The method for preparing polyurethane foam for thermal insulation strips according to claim 1, characterized in that: The molar ratio of ethylenediamine and 3,4-epoxy-1-butene in step A1 is 1:4, and the molar ratio of Si-Cl on lithium trimethylsilanolate, trifluoropropylmethylcyclotrisiloxane and trichlorosilane is 1:3:

1.

3. The method for preparing polyurethane foam for thermal insulation strips according to claim 1, characterized in that: The molar ratio of the intermediate and the modifier mentioned in step A2 is 1:

4.

4. The method for preparing polyurethane foam for thermal insulation strips according to claim 1, characterized in that: The ratio of styrene, deionized water and polyvinylpyrrolidone used in step B1 is 5 mL:45 mL:0.8 g, and the volume ratio of seed emulsion, ammonia, ethanol and tetraethyl orthosilicate is 3:0.6:60:

5.

5. The method for preparing polyurethane foam for thermal insulation strips according to claim 1, characterized in that: The amount of γ-aminopropyltriethoxysilane used in step B2 is 3% of the mass of the hollow nanospheres, and the molar ratio of the amino group on the aminated microspheres to propyltriethoxysilane is 1:

1.

6. The method for preparing polyurethane foam for thermal insulation strips according to claim 1, characterized in that: The ratio of functionalized microspheres, methyltriethoxysilane, ethanol, deionized water, hydrochloric acid and tetrabutyl titanate in step B3 is 1g:14mmol:40mL:3mL:1mL:4mmol.

7. The method for preparing polyurethane foam for thermal insulation strips according to claim 1, characterized in that: The ratio of the pretreated microspheres, tetraethyl orthosilicate, 3-mercaptopropyltrimethoxysilane, and ethanol used in step B4 is 1g:2g:0.2g:30mL.

8. A polyurethane foam for thermal insulation strips, characterized in that: Prepared according to any one of the preparation methods described in claims 1-7.

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