Bio-based flame-retardant polyurethane polystyrene foam

Abstract

The invention belongs to the technical field of polyurethane, and particularly relates to bio-based flame-retardant polyurethane polystyrene foam. The bio-based flame-retardant polyurethane polystyrene foam is prepared from the following raw materials in parts by weight: 60 to 75 parts of amino acid-based modified polyether polyol; 25-40 parts of a nitrogen and phosphorus-containing hydroxyl-terminated modified polymer; 380 to 440 parts of modified isocyanate; 100 to 130 parts of chlorinated paraffin; 40 to 60 parts of filler; 8-10 parts of silicone oil; 80 to 100 parts of a propellant; and 3-5 parts of a catalyst. Bio-based raw materials such as castor oil and amino acid are introduced into the molecular structure of the polyurethane polystyrene foam through chemical modification, so that the biodegradability of the material is improved; a proper polymeric monomer is screened, and a flame-retardant element chlorine is introduced into a polyether molecular structure through chemical polymerization and forms multi-element synergy with nitrogen and phosphorus elements bridged through ester bonds, so that the content of the flame-retardant element in the polystyrene foam material is effectively increased, and the flame retardance is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of polyurethane, and particularly relates to a bio-based flame-retardant polyurethane foaming glue. BACKGROUND

[0002] Polyurethane foam is widely used in daily life fields such as carpets, furniture and transportation. However, polyurethane foam is a high polymer flammable material, and the flame retardation of polyurethane foam is a difficult problem in the industry. In addition to traditional additive flame retardants, flame-retardant polyether has gradually formed various flame-retardant methods such as biomass flame-retardant, halogen flame-retardant and phosphorus flame-retardant through development. The biomass flame-retardant method, such as the method of containing phosphorus castor oil and straw liquefaction, has high cost and low yield, and is difficult to compete with traditional halogen flame-retardant; the phosphorus-nitrogen flame-retardant as a new type of high-efficiency additive flame-retardant has good thermal stability, small water solubility, long-lasting flame-retardant performance, low toxicity, and can overcome the compatibility problem of small molecule phosphorus flame-retardant with the flame-retardant material. In the past 20 years, it has developed rapidly. The addition of nitrogen element in the phosphorus flame-retardant often has the effects of improving thermal stability, overcoming hydrolysis, reducing smoke generation and other synergistic effects. The phosphorus-nitrogen intumescent flame-retardant can form a pyrophosphoric acid protective film when decomposed by heat, and then form an expanded foam-like carbon layer structure, which plays a role in heat insulation and oxygen resistance.

[0003] Chinese patent application CN102633972A, published on August 15, 2012, discloses a preparation method of phosphorus-halogen synergistic flame-retardant polyether polyol, which uses epoxy chloropropane to react with a product containing halogen aromatic diphenol after hydrolysis, but the process steps are relatively complicated; Chinese patent application CN118005882A, published on May 10, 2024, discloses a high-flame-retardant polyurethane rigid foam thermal insulation material, which uses hydrobromic acid as a halogen source and concentrated sulfuric acid in the process, which has a high risk factor for safe operation; Chinese patent application CN104004175A, published on August 31, 2016, discloses a flame-retardant polyether polyol, a combined polyether and a polyurethane foam, which uses diethanolamine and triethyl phosphite in a solvent to obtain a starting agent containing nitrogen and phosphorus elements by vacuum distillation, and then synthesizes a flame-retardant polyether with a multifunctional hydroxyl compound. The operation process is complex, and the reaction conditions are harsh due to the unstable nature of diethanolamine; Chinese patent application CN120554585A, published on August 29, 2025, discloses a multi-element synergistic flame-retardant polymer polyol, which introduces a halogen-containing monomer into the POP polymerization monomer to directly participate in free polymerization and synergize with the flame-retardant elements in the base polyether, but the flame-retardant effect is not obviously improved. SUMMARY

[0004] According to the deficiencies in the prior art above, the purpose of the present application is to provide a bio-based flame-retardant polyurethane foam adhesive, which introduces castor oil and amino acid and other bio-based raw materials into the structure of polyether polyol for foam adhesive preparation, so as to improve the biodegradability of the material.

[0005] The present application is implemented by using the following technical solutions: The bio-based flame-retardant polyurethane foam adhesive is composed of the following raw materials in parts by weight: Amino acid-based modified polyether polyol: 60-75 parts; Nitrogen and phosphorus-containing hydroxyl-terminated modified polymer: 25-40 parts; Modified isocyanate: 380-440 parts; Chlorinated paraffin: 100-130 parts; Filler: 40-60 parts; Silicone oil: 8-10 parts; Propellant: 80-100 parts; Catalyst: 3-5 parts.

[0006] Preferably, the amino acid-based modified polyether polyol is obtained by polymerizing epichlorohydrin under the action of a catalyst, with alanine and castor oil (functional group 2.7, hydroxyl value 162 mgKOH / g) as the initiator; the number average molecular weight is 550-700 g·mol -1 , and the functionality is 2.2.

[0007] Preferably, the preparation steps of the nitrogen and phosphorus-containing hydroxyl-terminated modified polymer are as follows: double-carboxyl amino acid, trimethylol phosphate and p-toluenesulfonic acid are added to a reaction kettle with a condenser, nitrogen is introduced to replace 3 times, the temperature is raised to 150-170℃, and stirring is performed for reaction; during the reaction, the by-products are continuously separated and distilled out through a rectifying column, and the reaction is performed for 6-8 hours; the molar ratio of the double-carboxyl amino acid to the trimethylol phosphate is 1:2.05; and the amount of the p-toluenesulfonic acid catalyst is 500-800 ppm of the total amount of the double-carboxyl amino acid and the trimethylol phosphate.

[0008] Preferably, the double-carboxyl amino acid is one of aspartic acid or glutamic acid.

[0009] Preferably, the preparation steps of the modified isocyanate are as follows: flame-retardant polyether polyol is added to a reaction kettle, the temperature is raised to 100-120℃, vacuum dehydration is performed until the water content is <0.05wt.%, the temperature is lowered to 60-80℃, isocyanate is added, and the reaction is performed until the -NCO content is 27-33wt.%, and the mass ratio of the isocyanate to the flame-retardant polyether is 100: (32-41).

[0010] Preferably, the flame-retardant polyether polyol is obtained by polymerizing propylene oxide under the action of a catalyst, using dibromoneopentyl glycol and INOVOL C204 as starting agents; the number average molecular weight is 600g / mol -1 , and the functionality is 2.

[0011] Preferably, the isocyanate is toluene diisocyanate and polymethylene polyphenyl isocyanate.

[0012] Preferably, the filler is expanded graphite, and by introducing a nano flame-retardant filler, an organic-inorganic composite flame-retardant system is constructed to reduce the smoke toxicity of the foaming glue.

[0013] Preferably, the catalyst is DMDEE.

[0014] Compared with the prior art, the present application has the following beneficial effects: (1) By introducing castor oil and amino acid and other bio-based raw materials into the structure of the polyether polyol, the biodegradability of the material can be improved when used for the preparation of foaming glue.

[0015] (2) By introducing nitrogen and phosphorus elements into the nitrogen and phosphorus-containing hydroxyl-terminated modified polymer through ester bond bridging, the synthesis method is simple, the cost is low, and industrialization is convenient; the chlorine element in the amino acid-based modified polyether polyol cooperates with each other and directly participates in the reaction, effectively improving the content of the flame-retardant elements in the foaming glue material, and further improving the flame retardance.

[0016] (3) By modifying the isocyanate with the bromine-containing flame-retardant polyether polyol, the bromine element is introduced into the structure of the isocyanate, the intrinsic flame retardance of the material is realized, and the risk of migration caused by the use of flame retardants is avoided. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical scheme of the present application more clear and explicit, the present application will be further described in detail below.

[0018] All the raw materials used in the examples are commercially available, except for special instructions.

[0019] Some of the raw materials used in the examples and comparative examples are described as follows: Tris (hydroxymethyl) phosphine oxide (THPO), Hubei Xingfa Group; Dibromoneopentyl glycol, Jiangsu Zhenri Chemical Co., Ltd.; Silicone oil: QG-8526, QG-6855, Shanghai Qiguang Trading Co., Ltd.; INOVOL C204 (hydroxyl value 280mgKOH / g, functionality 2), Shandong YINOWEI New Material Co., Ltd.; INOVOL C206 (hydroxyl value 187mgKOH / g, functionality 2), Shandong YINOWEI New Material Co., Ltd. Toluene diisocyanate (2,4 TDI about 80%, 2,6 TDI about 20%), Wanhua Chemical Group Co., Ltd.; Polymeric methylene polyphenyl isocyanate, Wanhua Chemical Group Co., Ltd.; The preparation method of the flame-retardant polyether polyol is: 393 g of dibromoneopentyl glycol, 600 g of INOVOL C204 and 0.93 g of DMC catalyst are added to a high-pressure reaction kettle, heated to 130 DEG C, and 80 g of propylene oxide is added dropwise to initiate. After the pressure drops to -0.08 MPa, the remaining 830 g of propylene oxide is gradually added dropwise into the reaction kettle, and the pressure in the reaction kettle is controlled to be ≤0.3 MPa. After the reaction is completed, the monomer is removed for 0.5 h to obtain the flame-retardant polyether polyol with a functionality of 2 and a number average molecular weight of 600 g / mol -1 .

[0020] Example 1 The preparation steps of the amino acid-based modified polyether polyol are: 445 g of alanine and 1870 g of castor oil (hydroxyl value is 162 mgKOH / g), 2.24 g of boron trifluoride catalyst are added to a pressure-resistant reaction kettle, heated to 100 DEG C, vacuumized to -0.09 MPa, and then nitrogen is introduced for 2 h to remove small molecule monomers and water. Nitrogen is introduced, and 2170 g of epichlorohydrin is added dropwise. After the dropwise addition is completed, the reaction is carried out for 2 h. The unreacted residual monomers are removed by vacuumization to obtain the amino acid-based modified polyether polyol with Mn of 600 g / mol and a functionality of 2.2.

[0021] The preparation steps of the nitrogen and phosphorus-containing terminal hydroxyl group modified polymer are: 147 g of glutamic acid, 287 g of trimethylol phosphate and 0.217 g of p-toluenesulfonic acid are added to a reaction kettle with a condenser, and nitrogen is introduced for 3 times. The temperature is raised to 150 DEG C, and the reaction is stirred. During the reaction process, the by-products are continuously separated and distilled off through the rectifying column. The reaction is carried out for 7 h to obtain the nitrogen and phosphorus-containing terminal hydroxyl group modified polymer with Mn of 377 g / mol and a functionality of 4.

[0022] The preparation steps of the isocyanate-based flame-retardant prepolymer are: 82 g of flame-retardant polyether polyol is added to a reaction kettle, heated to 120 DEG C, vacuum dehydrated to a water content of <0.05 wt.%, and then cooled to 70 DEG C. 200 g of toluene diisocyanate and 100 g of polymeric methylene polyphenyl isocyanate are added, and the reaction is carried out at 70 DEG C for 2 h. The NCO content is 30.39%.

[0023] The bio-based flame-retardant polyurethane foam adhesive is composed of the following raw materials in parts by weight: Amino acid-based modified polyether polyol: 65 parts; Nitrogen and phosphorus-containing terminal hydroxyl group modified polymer: 35 parts; Modified isocyanate: 427 parts; Chlorinated paraffin: 100 parts; Expanded graphite: 50 parts; QG-8526: 5 parts; QG-6855: 3 parts; Propane butane: 40 parts; Dimethyl ether: 50 parts; DMDEE: 5 parts.

[0024] The above raw materials are mixed uniformly at room temperature to obtain a bio-based flame-retardant polyurethane foam adhesive.

[0025] Example 2 The preparation steps of the amino acid-based modified polyether polyol are as follows: 445 g of alanine and 1870 g of castor oil (hydroxyl value is 162 mgKOH / g) are added to a pressure-resistant reaction kettle, 2.03 g of boron trifluoride catalyst is added, the temperature is raised to 100°C, vacuum is extracted to-0.09 MPa, nitrogen is blown for 2 h to remove small molecule monomers and water, nitrogen is introduced, 1750 g of epichlorohydrin is added dropwise, after the dropwise addition is completed, the reaction is carried out for 2 h; vacuum is extracted to remove unreacted residual monomers, and an amino acid-based modified polyether polyol with Mn of 550 g / mol and a functionality of 2.2 is obtained.

[0026] The preparation steps of the nitrogen-containing phosphorus terminal hydroxyl group modified polymer are as follows: 147 g of glutamic acid, 287 g of trimethylol phosphate, and 0.347 g of p-toluenesulfonic acid are added to a reaction kettle with a condenser, nitrogen is introduced for replacement for 3 times, the temperature is raised to 170°C, and the reaction is stirred, during the reaction, the by-products are continuously separated and distilled off through a rectifying column, the reaction is carried out for 6 h, and a nitrogen-containing phosphorus terminal hydroxyl group modified polymer with Mn of 377 g / mol and a functionality of 4 is obtained.

[0027] The preparation steps of the isocyanate-based flame-retardant prepolymer are as follows: 103 g of flame-retardant polyether polyol is added to a reaction kettle, the temperature is raised to 100°C, vacuum dehydration is carried out until the water content is <0.05wt.%, the temperature is lowered to 60°C, 200 g of toluene diisocyanate and 100 g of polymethylene polyphenyl isocyanate are added, and the reaction is carried out at 60°C for 2.5 h, and the NCO content is 28.12%.

[0028] The bio-based flame-retardant polyurethane foam adhesive is composed of the following raw materials in parts by weight: Amino acid-based modified polyether polyol: 75 parts; Nitrogen-containing phosphorus terminal hydroxyl group modified polymer: 25 parts; Modified isocyanate: 440 parts; Chlorinated paraffin: 120 parts; Expanded graphite: 60 parts; QG-8526: 5 parts; QG-8526: 6 parts; Propane-butyane: 40 parts; Dimethyl ether: 40 parts; DMDEE: 4 parts.

[0029] The above raw materials are mixed uniformly at room temperature to obtain the bio-based flame-retardant polyurethane foam adhesive.

[0030] Example 3 The preparation steps of the amino acid-based modified polyether polyol are as follows: 445 g of alanine and 1870 g of castor oil (hydroxyl value of 162 mg KOH / g) are added to a pressure-resistant reaction kettle, 2.24 g of boron trifluoride catalyst is added, the temperature is raised to 100°C, vacuum is extracted to-0.09 MPa, nitrogen is blown for 2 h to remove small molecule monomers and water, nitrogen is introduced, 2940 g of epichlorohydrin is added dropwise, after the dropwise addition is completed, the reaction is carried out for 2 h, vacuum is extracted to remove unreacted residual monomers, and an amino acid-based modified polyether polyol with Mn of 700 g / mol and a functionality of 2.2 is obtained.

[0031] The preparation steps of the nitrogen-containing phosphorus terminal hydroxyl group modified polymer are as follows: 133 g of aspartic acid, 287 g of trimethylol phosphate, and 0.336 g of p-toluenesulfonic acid are added to a reaction kettle with a condenser, nitrogen is introduced for replacement for 3 times, the temperature is raised to 150°C, and stirring is carried out for reaction, during the reaction, byproduct is continuously separated and distilled off through a rectifying column, the reaction is carried out for 8 h, a nitrogen-containing phosphorus terminal hydroxyl group modified polymer with Mn of 391 g / mol and a functionality of 4 is obtained.

[0032] The preparation steps of the isocyanate-based flame-retardant prepolymer are as follows: 64 g of flame-retardant polyether polyol is added to a reaction kettle, the temperature is raised to 110°C, vacuum dehydration is carried out until the water content is <0.05 wt.%, the temperature is lowered to 80°C, 200 g of toluene diisocyanate and 100 g of polymethylene polyphenyl isocyanate are added, and reaction is carried out at 80°C for 2 h, and the NCO content is 32.59%.

[0033] The bio-based flame-retardant polyurethane foam adhesive is composed of the following raw materials in parts by weight: Amino acid-based modified polyether polyol: 60 parts; Nitrogen-containing phosphorus terminal hydroxyl group modified polymer: 40 parts; Modified isocyanate: 380 parts; Chlorinated paraffin: 130 parts; Expanded graphite: 40 parts; QG-8526: 6 parts; QG-6855: 4 parts; Propane-butyane: 40 parts; Dimethyl ether: 60 parts; DMDEE: 3 parts.

[0034] The above raw materials are mixed uniformly at room temperature to obtain a bio-based flame-retardant polyurethane foaming adhesive.

[0035] Comparative Example 1 A polyether polyol with a number average molecular weight of 600 g·mol -1 was used instead of the amino acid-based modified polyether polyol (prepared by catalyzing the polymerization of propylene oxide using propylene glycol and glycerol as starting agents, with a functionality of 2.2), and the other raw materials and preparation methods were the same as in Example 1.

[0036] Comparative Example 2 A pentaerythritol polyether polyol (prepared by catalyzing the polymerization of propylene oxide using pentaerythritol as a starting agent, with a functionality of 4 and a number average molecular weight of 377 g·mol -1 ) was used instead of the nitrogen and phosphorus-containing hydroxyl-terminated modified polymer, and the other raw materials and preparation methods were the same as in Example 1.

[0037] Comparative Example 3 INOVOL C206 was used instead of the flame-retardant polyether polyol to prepare the modified isocyanate, and the preparation steps were the same as those described in Example 1 for the preparation of the modified isocyanate, and the other raw materials and preparation methods were the same as in Example 1.

[0038] The polyurethane foaming adhesives prepared in Examples 1-3 and Comparative Examples 1-3 were tested for performance, and the testing methods were as follows: The cumulative biodegradation percentage was tested in accordance with GB / T 19276.1, and the limiting oxygen index was tested in accordance with GB / T 2406.1-2008.

[0039] The test results are shown in Table 1.

[0040] Table 1 Performance test results of Examples 1-3 and Comparative Examples 1-3

[0041] As can be seen from the above data in Table 1, the introduction of bio-based raw materials such as castor oil and amino acids into the foaming adhesive system can significantly improve the biodegradability of the material; the synergistic effect of nitrogen, phosphorus, chlorine and other flame-retardant elements achieves the intrinsic flame-retardant performance of the material, and the flame-retardant effect is improved.

Claims

1. A bio-based flame-retardant polyurethane foam adhesive, characterized by, It is composed of the following raw materials in weight parts: Amino acid-based modified polyether polyol: 60~75 parts; Nitrogen-containing phosphorus end-hydroxyl modified polymer: 25~40 parts; Modified isocyanate: 380~440 parts; Chlorinated paraffin: 100~130 parts; Filler: 40~60 parts; Silicone oil: 8~10 parts; Propellant: 80~100 parts; Catalyst: 3~5 parts.

2. The bio-based flame-retardant polyurethane foam glue according to claim 1, characterized in that, The amino acid-based modified polyether polyol is obtained by polymerizing epichlorohydrin under the action of a catalyst with alanine and castor oil as starting agents; the number average molecular weight is 550-700 g·mol -1 , and the functionality is 2.

2.

3. The bio-based flame-retardant polyurethane foam glue according to claim 1, characterized in that, The preparation steps of the nitrogen-containing phosphorus end-hydroxyl modified polymer are as follows: double carboxyl amino acid, trimethylol phosphate and p-toluenesulfonic acid are added to a reaction kettle with a condenser, nitrogen is introduced to replace 3 times, the temperature is raised to 150~170℃, and the reaction is stirred; during the reaction, the by-products are continuously separated and distilled off through a rectifying column, and the reaction is carried out for 6~8h; the molar ratio of the double carboxyl amino acid to the trimethylol phosphate is 1:2.05; and the amount of the p-toluenesulfonic acid catalyst is 500~800ppm of the total amount of the double carboxyl amino acid and the trimethylol phosphate.

4. The bio-based flame-retardant polyurethane foam glue according to claim 3, characterized in that, The double carboxyl amino acid is one of aspartic acid or glutamic acid.

5. The bio-based flame-retardant polyurethane foam glue according to claim 1, characterized in that, The preparation steps of the modified isocyanate are as follows: flame-retardant polyether polyol is added to a reaction kettle, the temperature is raised to 100~120℃, vacuum dehydration is carried out until the water content is <0.05wt.%, the temperature is lowered to 60~80℃, isocyanate is added, and the reaction is carried out until the -NCO content is 27~33wt.%, and the mass ratio of the isocyanate to the flame-retardant polyether is 100: (32~41).

6. The bio-based flame-retardant polyurethane foam glue according to claim 5, characterized in that, The flame-retardant polyether polyol is obtained by polymerizing propylene oxide under the action of a catalyst and using dibromoneopentyl glycol and INOVOL C204 as starting agents; the number average molecular weight is 600 g·mol -1 , and the functionality is 2.

7. The bio-based flame-retardant polyurethane foam glue according to claim 5, characterized in that, The isocyanate is toluene diisocyanate and polymethylene polyphenyl isocyanate.

8. The bio-based flame-retardant polyurethane foam glue according to claim 1, characterized in that, The filler is expanded graphite, an organic-inorganic composite flame-retardant system is constructed by introducing nano flame-retardant fillers, and the smoke toxicity of the foaming glue is reduced.

9. The bio-based flame-retardant polyurethane foam glue according to claim 1, wherein, The catalyst is DMDEE.

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