Application of a polyol composition in the preparation of thermally insulating polyurethane foam

Abstract

This invention discloses the application of a polyol composition in the preparation of thermally insulating polyurethane foam, belonging to the field of polymer materials technology. The polyol composition provided by this invention comprises the following components in parts by weight: 100 parts polyol, 0.2-2 parts first catalyst, 2-6 parts blowing agent, 3-8 parts flame retardant, and 0.5-0.8 parts anti-aging agent. The polyol is a polyether-polyester block polyol, which contains block-structured polyether segments and polyester segments. The polyester segments can make the hydrogen bond network denser, reducing microphase separation, effectively reducing the heat conduction path, and improving the thermal resistance performance of the material. The flexibility of the ether segments helps to make the cell walls denser, reducing gas convection and heat radiation. Both components exert their respective properties, effectively improving the thermal insulation performance of the polyurethane foam.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to the application of a polyol composition in the preparation of thermally insulating polyurethane foam. Background Technology

[0002] Polyurethane foam is a thermal insulation material widely used in construction, industry, home appliances, and cold chain transportation. Polyol compositions are one of the key raw materials for preparing polyurethane foam, typically composed of a mixture of various polyols (such as polyether polyols and polyester polyols), which react with isocyanates to form polyurethane foam. Polyether polyols impart good flexibility and low-temperature performance to the foam, while polyester polyols provide higher strength and heat resistance.

[0003] However, traditional polyol compositions have some thermal insulation drawbacks. While polyurethane foam made from traditional polyol compositions possesses some thermal insulation properties, it remains insufficient for extremely low or high temperature insulation requirements. As temperature increases, the thermal motion of the polyol composition intensifies, leading to a decrease in the stability of the internal bubble structure and an increase in thermal conductivity. At low temperatures, the material may become brittle, affecting its insulation performance. Therefore, finding a new polyol composition suitable for preparing polyurethane foam is essential. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide an application of a polyol composition in the preparation of thermal insulation polyurethane foam.

[0005] The first aspect of the present invention is to provide an application of a polyol composition in the preparation of thermal insulation foamed polyurethane, wherein the polyol composition comprises the following components by weight: 100 parts polyol, 0.2-2 parts first catalyst, and 2-6 parts foaming agent;

[0006] The polyol is a polyether-polyester block polyol, which is prepared by the following steps:

[0007] S1: Add hydroxyl monomer, epoxy compound and second catalyst to reactor one to carry out ring-opening polymerization reaction to obtain polyether polyol prepolymer;

[0008] S2: Add a lactone compound or lactone compound and a polyether polyol prepolymer to the second reactor, and obtain a polyether-polyester block polyol prepolymer through a ring-opening polymerization reaction;

[0009] S3: Add an epoxy compound and a polyether-polyester block polyol prepolymer to reactor three, and obtain the polyether-polyester block prepolymer through a polycondensation reaction;

[0010] S4: Repeat S2-S3 to obtain polyether-polyester block polyol.

[0011] It should be noted that this invention creatively uses polyether-polyester block polyols in the preparation of thermally insulating polyurethane foam. The polymer chains of the polyether-polyester block polyols contain polyether segments and polyester segments. The polyester segments can make the hydrogen bond network denser, thereby reducing microphase separation, and the resulting hard segment structure is more regular, which can effectively reduce the heat conduction path and improve the thermal resistance performance of the material. The flexibility of the ether segments helps to make the cell walls denser, reducing gas convection and thermal radiation, thereby reducing the thermal conductivity.

[0012] In some embodiments, the hydroxyl monomer is selected from water, ethylene glycol, ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, and polyethylene glycol.

[0013] In some embodiments, the epoxy compounds in S1 and S3 are both , where R 4 It is a C0-C6 aliphatic alkyl group or a C6-C6 aliphatic alkyl group. 20 Aromatic alkyl group; the molar ratio of the epoxide in S1 or S3 to the hydroxyl monomer in S1 is 20-50:1.

[0014] In some embodiments, the second catalyst is selected from one or more alkali metal catalysts; the amount of the second catalyst added is 0.1%-2% of the molar amount of the epoxide compound.

[0015] In some embodiments, the lactone compound is C4-C. 10 Lactones; lactone compounds are C4-C 10 Cyclic lactones.

[0016] In some embodiments, the molar ratio of the lactone compound or lactone compound to the hydroxyl monomer is 20-50:1.

[0017] In some embodiments, the reaction temperature of S1, S2, S3 and S4 is 100-250°C and the reaction time is 6-25 h.

[0018] In some embodiments, the blowing agent is an LBA blowing agent; the first catalyst is an amine catalyst and / or a tin catalyst.

[0019] In some embodiments, the polyol composition further includes, by weight, 3-8 parts of flame retardant and 0.5-0.8 parts of anti-aging agent.

[0020] In some embodiments, the flame retardant is selected from benzomelamine, pentaerythritol phosphate, and decabromodiphenyl ether; the anti-aging agent is selected from triphenyl phosphite, hydroquinone, and benzotriazole compounds.

[0021] The "repeating S2-S3" mentioned in step S4 above can be done once or multiple times; this article does not impose too many restrictions.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] This invention provides the application of a polyol composition containing a polyether-polyester block polyol in the preparation of thermally insulating polyurethane foam. The polyether segments and polyester segments in the polyether-polyester block polyol form a block structure. Compared with a simple physical mixture of polyether polyol and polyester polyol or a polymer with random polyether segments and polyester segments, the block polymer of this application can give full play to the respective characteristics of the polyether segments and polyester segments, and ultimately improve the thermal insulation performance of the polyurethane foam. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the embodiments.

[0025] Example 1

[0026] The application of a polyol composition in the preparation of thermal insulation foamed polyurethane, wherein the polyol composition comprises the following components by weight: 100 parts polyol, 1 part N,N-dimethylcyclohexylamine, 4 parts LBA blowing agent, 5 parts benzomelamine, and 0.7 parts triphenyl phosphite.

[0027] The polyol is a polyether-polyester block polyol, which is prepared by the following steps:

[0028] S1: Ethylene glycol, ethylene oxide, and the second catalyst, alumina, are added to reactor one and subjected to a ring-opening polymerization reaction at 150°C for 6 h to obtain a polyether polyol prepolymer; wherein, the amount of the second catalyst added is 0.1% of the molar amount of the epoxide; the molar ratio of the epoxide compound used in S1 to the hydroxyl monomer in S1 is 20-50:1;

[0029] S2: Add glycolide and polyether polyol prepolymer to reactor II, and perform ring-opening polymerization at 160°C for 22 h to obtain polyether-polyester block polyol prepolymer; wherein the molar ratio of glycolide compound or lactone compound to hydroxyl monomer is 35:1.

[0030] S3: Ethylene oxide and polyether-polyester block polyol prepolymer are added to reactor three, and polycondensation reaction is carried out at 170°C for 7 h to obtain polyether-polyester block prepolymer; wherein, the molar ratio of the epoxy compound used in S3 to the hydroxyl monomer in S1 is 35:1.

[0031] S4: Repeat S2-S3 once to obtain polyether-polyester block polyol.

[0032] Example 2

[0033] The application of a polyol composition in the preparation of thermal insulation foamed polyurethane, wherein the polyol composition comprises the following components by weight: 100 parts polyol, 2 parts dibutyltin dilaurate, 6 parts LBA blowing agent, 8 parts flame retardant, and 0.8 parts anti-aging agent.

[0034] The polyol is a polyether-polyester block polyol, which is prepared by the following steps:

[0035] S1: Ethylene glycol, propylene oxide, and the second catalyst palladium oxide are added to reactor one and subjected to a ring-opening polymerization reaction at 160°C for 8 h to obtain a polyether polyol prepolymer; wherein, the amount of the second catalyst added is 2% of the molar amount of the epoxy compound; the molar ratio of the epoxy compound to the hydroxyl monomer used in S1 is 50:1.

[0036] S2: Add lactide and polyether polyol prepolymer to reactor II, and perform ring-opening polymerization at 170°C for 20 hours to obtain polyether-polyester block polyol prepolymer; wherein the molar ratio of lactide compound or lactone compound to hydroxyl monomer is 50:1.

[0037] S3: Add propylene oxide and polyether-polyester block polyol prepolymer to reactor three, and perform polycondensation reaction at 180°C for 5 h to obtain polyether-polyester block prepolymer; wherein, the molar ratio of epoxy compound to hydroxyl monomer used in S3 is 50:1.

[0038] S4: Repeat S2-S3 once to obtain polyether-polyester block polyol.

[0039] Example 3

[0040] The application of a polyol composition in the preparation of thermal insulation foamed polyurethane, wherein the polyol composition comprises the following components by weight: 100 parts polyol, 0.2 parts triethylenediamine, 2 parts LBA blowing agent, 3 parts pentaerythritol phosphate, and 0.5 parts hydroquinone.

[0041] The polyol is a polyether-polyester block polyol, which is prepared by the following steps:

[0042] S1: Propylene glycol, phenylene oxide, and beryllium oxide (a second catalyst) are added to reactor 1 and subjected to ring-opening polymerization at 130°C for 8 h to obtain a polyether polyol prepolymer; wherein, the amount of the second catalyst added is 0.1% of the molar amount of the epoxy compound; the molar ratio of the epoxy compound used in S1 to the hydroxyl monomer in S1 is 20:1;

[0043] S2: Add valerol lactone and polyether polyol prepolymer to reactor II, and perform ring-opening polymerization at 150°C for 24 h to obtain polyether-polyester block polyol prepolymer; wherein the molar ratio of lactone compound or lactone compound to hydroxyl monomer is 20:1.

[0044] S3: Add styrene oxide and polyether-polyester block polyol prepolymer to reactor three, and perform polycondensation reaction at 150°C for 8 h to obtain polyether-polyester block prepolymer; wherein, the molar ratio of the epoxy compound used in S3 to the hydroxyl monomer in S1 is 20:1.

[0045] S4: Repeat S2-S3 once to obtain polyether-polyester block polyol.

[0046] Example 4

[0047] The application of a polyol composition in the preparation of thermal insulation foamed polyurethane, wherein the polyol composition comprises the following components by weight: 100 parts polyol, 1.4 parts dioctyltin dilaurate, 5 parts LBA blowing agent, 4 parts decabromodiphenyl ether, and 0.7 parts benzotriazole compound.

[0048] The polyol is a polyether-polyester block polyol, which is prepared by the following steps:

[0049] S1: Butanediol, styrene oxide, and sodium hydroxide (a second catalyst) are added to reactor 1 and subjected to ring-opening polymerization at 150°C for 7 h to obtain a polyether polyol prepolymer; wherein, the amount of the second catalyst added is 1.5% of the molar amount of the epoxy compound; the molar ratio of the epoxy compound used in S1 to the hydroxyl monomer in S1 is 35:1.

[0050] S2: Add caprolactone and polyether polyol prepolymer to reactor II, and perform ring-opening polymerization at 160°C for 22 h to obtain polyether-polyester block polyol prepolymer; wherein the molar ratio of lactone compound or lactone compound to hydroxyl monomer is 30:1.

[0051] S3: Add epoxy styrene propane and polyether-polyester block polyol prepolymer to reactor three, and perform polycondensation reaction at 170°C for 6 h to obtain polyether-polyester block prepolymer; wherein, the molar ratio of the epoxy compound used in S3 to the hydroxyl monomer in S1 is 35:1.

[0052] S4: Repeat S2-S3 once to obtain polyether-polyester block polyol.

[0053] Example 5

[0054] The application of a polyol composition in the preparation of thermal insulation foamed polyurethane, wherein the polyol composition comprises the following components by weight: 100 parts polyol, 0.6 parts triethylamine, 5 parts LBA blowing agent, 6 parts benzomelamine, and 0.6 parts hydroquinone.

[0055] The polyol is a polyether-polyester block polyol, which is prepared by the following steps:

[0056] S1: Polyethylene glycol, ethylene oxide, and potassium hydroxide (a second catalyst) are added to reactor one and subjected to ring-opening polymerization at 140°C for 6 h to obtain a polyether polyol prepolymer; wherein, the amount of the second catalyst added is 0.8% of the molar amount of the epoxy compound; the molar ratio of the epoxy compound used in S1 to the hydroxyl monomer in S1 is 45:1;

[0057] S2: Add glycolide and polyether polyol prepolymer to reactor II, and perform ring-opening polymerization at 155°C for 23 h to obtain polyether-polyester block polyol prepolymer; wherein the molar ratio of glycolide compound or lactone compound to hydroxyl monomer is 35:1.

[0058] S3: Ethylene oxide and polyether-polyester block polyol prepolymer are added to reactor three, and polycondensation reaction is carried out at 175°C for 6 h to obtain polyether-polyester block prepolymer; wherein, the molar ratio of the epoxy compound used in S3 to the hydroxyl monomer in S1 is 45:1.

[0059] S4: Repeat S2-S3 once to obtain polyether-polyester block polyol.

[0060] Comparative Example 1

[0061] It is basically the same as Example 1, except that the polyether-polyester block polyol is replaced with the same amount of polyol mixture;

[0062] The polyol mixture was prepared by the following steps:

[0063] S1: Ethylene glycol, ethylene oxide and alumina catalyst were added to reactor one and ring-opening polymerization was carried out at 150°C for 6 h to obtain polyether polyol;

[0064] S2: Add ethylene glycol, diacid and zinc acetate catalyst to reactor II, and carry out esterification reaction at 160°C under nitrogen protection. After the acid value decreases, raise the temperature to 220°C to carry out polycondensation reaction to obtain polyester polyol.

[0065] S3: Mix polyether polyol and polyester polyol evenly, and vacuum dehydrate at 120°C for 3 hours to obtain a polyol mixture.

[0066] Comparative Example 2

[0067] It is basically the same as Example 1, except that S3 and S4 are omitted, that is, the polyether-polyester block polyol is replaced with polyether-polyester block polyol prepolymer.

[0068] To demonstrate that the polyol composition provided by this invention can improve the thermal insulation performance of polyurethane foam, performance tests were conducted on polyurethane foam containing the polyol composition provided by this invention. The test results are shown in Table 1.

[0069] The polyol compositions prepared in Examples 1-5 and Comparative Examples 1-2 were then used to prepare foamed polyurethanes according to the following steps:

[0070] (1) According to the dosage of each component in the examples / comparative examples, the first catalyst, foaming agent, flame retardant and anti-aging agent are added to the polyol and stirred evenly to form a mixture;

[0071] (2) After preheating the isocyanate at 45°C, slowly add it to the mixture prepared in step (1) and stir at a high speed of 600 rpm for 5 min. After thorough mixing, foamed material is obtained.

[0072] (3) Pour the above foaming material into a pre-prepared mold and allow it to foam naturally at room temperature to form a foamed cotton preform;

[0073] (4) The above-mentioned foamed cotton blank is placed in an oven and cured at 100°C for 36 h to obtain foamed polyurethane.

[0074] Test method:

[0075] Strength conforms to standard GB / T8813-2020;

[0076] Thermal conductivity according to standard The thermal conductivity was measured using a thermal conductivity tester, and the sample size was 200mm×200mm×20mm.

[0077] The oxygen index was tested in accordance with the standard GB / T2918-1988.

[0078] Table 1

[0079]

[0080] As can be seen from Table 1, the polyurethane foam containing the polyol prepared in the embodiments of the present invention not only has excellent thermal insulation properties, but also good mechanical properties, which can meet the market demand.

[0081] As can be seen from Comparative Example 1, since the polyol mixture obtained by simple physical mixing does not have a block structure, it cannot give full play to the advantages of polyether segments and polyester segments. The random polyol used in Comparative Example 2 also does not have a block structure, resulting in a significant decrease in the thermal insulation performance of the foamed polyurethane.

[0082] The above descriptions are merely some embodiments of the present invention. Those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. The application of a polyol composition in the preparation of thermally insulating polyurethane foam, characterized in that, The polyol composition comprises, by weight, the following components: 100 parts polyol, 0.2-2 parts first catalyst, 2-6 parts foaming agent, 3-8 parts flame retardant, and 0.5-0.8 parts anti-aging agent; The polyol is a polyether-polyester block polyol, which is prepared by the following steps: S1: Add hydroxyl monomer, epoxy compound and second catalyst to reactor one to carry out ring-opening polymerization reaction to obtain polyether polyol prepolymer; S2: Add a lactone compound or lactone compound and the polyether polyol prepolymer to the second reactor, and obtain a polyether-polyester block polyol prepolymer by ring-opening polymerization reaction; S3: Add the epoxy compound and the polyether-polyester block polyol prepolymer to reactor three, and obtain the polyether-polyester block prepolymer through polycondensation reaction; S4: Repeat S2-S3 to obtain the polyether-polyester block polyol; The flame retardant is selected from one of benzomelamine, pentaerythritol phosphate, and decabromodiphenyl ether; the anti-aging agent is selected from one of triphenyl phosphite, hydroquinone, and benzotriazole compounds.

2. The application of the polyol composition according to claim 1 in the preparation of thermally insulating polyurethane foam, characterized in that, The hydroxyl monomer is selected from one of water, ethylene glycol, ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, and polyethylene glycol.

3. The application of the polyol composition according to claim 2 in the preparation of thermally insulating polyurethane foam, characterized in that, The epoxy compounds in S1 and S3 are all... , where R 4 It is a C0-C6 aliphatic alkyl group or a C6-C6 aliphatic alkyl group. 20 Aromatic alkyl group; the molar ratio of the epoxide in S1 or S3 to the hydroxyl monomer in S1 is 20-50:

1.

4. The application of the polyol composition according to claim 1 in the preparation of thermally insulating polyurethane foam, characterized in that, The second catalyst is selected from one or more alkali metal catalysts; the amount of the second catalyst added is 0.1%-2% of the molar amount of the epoxy compound.

5. The application of the polyol composition according to claim 1 in the preparation of thermally insulating polyurethane foam, characterized in that, The lactone compound is C4-C. 10 Lactose; the lactone compound is C4-C 10 Cyclic lactones.

6. The application of the polyol composition according to claim 5 in the preparation of thermally insulating polyurethane foam, characterized in that, The molar ratio of the lactone compound or lactone compound to the hydroxyl monomer is 20-50:

1.

7. The application of the polyol composition according to claim 1 in the preparation of thermally insulating polyurethane foam, characterized in that, The reaction temperature of S1, S2, S3 and S4 is 100-250℃, and the reaction time is 6-25 h.

8. The application of the polyol composition according to claim 1 in the preparation of thermally insulating polyurethane foam, characterized in that, The foaming agent is LBA foaming agent; the first catalyst is an amine catalyst and / or a tin catalyst.

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