A composite polyurethane catalyst and preparation method thereof

Abstract

The present invention belongs to the technical field of polyurethane synthesis, and specifically relates to a composite polyurethane catalyst and a preparation method thereof. The catalyst is based on bismuth isooctanoate. On the one hand, the surface of bismuth isooctanoate is activated by sodium dodecyl sulfonate to promote better modification of the bismuth isooctanoate by organic tertiary amines, thereby improving the catalytic performance. On the other hand, the selectivity of the catalyst is significantly improved by introducing metavanadate ions during the synthesis process, thereby inhibiting the generation of by-products. The composite polyurethane catalyst prepared by the present invention is not only safe and environmentally friendly, but also has good selectivity, few by-products, and high polyurethane yield in the process of catalyzing the polycondensation reaction of polyols and polyisocyanates to generate polyurethane. The prepared polyurethane has excellent mechanical properties and is suitable for wide industrial application.

Description

Technical Field

[0001] The invention belongs to the technical field of polyurethane synthesis, and particularly relates to a composite polyurethane catalyst and a preparation method thereof. Background Art

[0002] Polyurethane is a polymer material with excellent mechanical properties formed by the condensation reaction of polyols and polyisocyanates. This polymer material can be used to manufacture plastics, rubber, hard and soft foams, adhesives, coatings, paints and other products. Due to its excellent wear resistance, impact resistance, UV resistance, and high and low temperature resistance, it is widely used in construction, automobiles, light industry, textiles, petrochemicals, metallurgy, electronics, national defense, medical care, machinery and many other fields.

[0003] In the process of polyurethane synthesis, the catalyst is one of the important factors affecting the reaction. At present, the most widely used catalyst is the metal organotin catalyst, but organotin compounds can cause harm to the human body, especially the commonly used dibutyltin dilaurate. Long-term contact can cause neurasthenia and is not suitable for large-scale application. With the continuous deepening of research, a variety of environmentally friendly catalysts have gradually been derived, mainly organic bismuth, organic zinc, organic zirconium catalysts, etc. However, in the actual production process, the use of these catalysts will not only produce more by-product polyurea, but also affect the mechanical properties of polyurethane materials, causing the tensile strength and elongation at break of polyurethane materials to decrease. Therefore, it is of great significance to provide a polyurethane catalyst with excellent selectivity and excellent mechanical properties of polyurethane materials. Summary of the invention

[0004] Aiming at the problem that the environmentally friendly polyurethane catalyst in the prior art has poor selectivity and affects the mechanical properties of the polyurethane material, the present invention provides a composite polyurethane catalyst and a preparation method thereof. The catalyst is mainly composed of bismuth isooctanoate. On the one hand, the surface of bismuth isooctanoate is activated by sodium dodecyl sulfonate to promote better modification of the bismuth isooctanoate by organic tertiary amines and improve the catalytic performance. On the other hand, the selectivity of the catalyst is significantly improved by introducing metavanadate ions during the synthesis process, and the generation of by-products is suppressed. The composite polyurethane catalyst prepared by the present invention is not only safe and environmentally friendly, but also has good selectivity, few by-products, and high polyurethane yield in the process of catalyzing the polycondensation reaction of polyols and polyisocyanates to generate polyurethane. The prepared polyurethane has excellent mechanical properties and is suitable for industrial wide application.

[0005] The first aspect of the present invention provides a method for preparing a composite polyurethane catalyst, comprising the following steps:

[0006] S1: dissolving a bismuth salt in a nitric acid solution to form a solution A;

[0007] S2: dissolving isooctanoic acid, sodium metavanadate and sodium dodecyl sulfate in isopropanol and stirring thoroughly to obtain solution B;

[0008] S3: mixing solution A and solution B, stirring and mixing them evenly, and placing them in a high-pressure reactor for solvothermal reaction to obtain a precursor;

[0009] S4: mixing an organic tertiary amine and isopropanol to form a solution C;

[0010] S5: Dispersing the precursor in solution C, fully modifying it under heating conditions, and then washing and filtering to obtain a composite polyurethane catalyst.

[0011] Furthermore, in step S1, the bismuth salt is at least one of bismuth nitrate pentahydrate and bismuth acetate.

[0012] Furthermore, in step S1, the concentration of the nitric acid solution is 1-2 mol / L, and the addition ratio of the bismuth salt to the nitric acid solution is 0.01 mol:50-80 mL.

[0013] Furthermore, the ratio of bismuth salt, isooctanoic acid, sodium metavanadate, sodium dodecylsulfonate and isopropyl alcohol is 0.01 mol: 0.03 mol: 0.001 mol: 0.005 mol: 50-80 mL.

[0014] Furthermore, in step S3, a solvothermal reaction is carried out after stirring at 80-90° C. for 3-6 hours; the solvothermal reaction temperature is 160-180° C., and the reaction time is 8-10 hours.

[0015] Furthermore, in step S4, the addition ratio of the organic tertiary amine and isopropanol is 0.05 mol:30-50 mL.

[0016] Furthermore, in step S4, the organic tertiary amine is triethylamine, triethylenediamine, N-ethylmorpholine or N,N-dimethylethanolamine.

[0017] Furthermore, in step S5, the addition ratio of the precursor to solution C is 5-8 g:30-50 mL.

[0018] Furthermore, in step S5, the modification is carried out by stirring at 80 to 90° C. for 5 to 8 hours.

[0019] The second aspect of the present invention provides a composite polyurethane catalyst prepared by the preparation method of the composite polyurethane catalyst.

[0020] The beneficial effects achieved by one or more technical solutions of the present invention are as follows:

[0021] 1. The composite polyurethane catalyst provided by the present invention is based on bismuth isooctanoate as the main body, but considering that simple bismuth isooctanoate catalysis will produce more byproduct polyurea, the synthesis process of bismuth isooctanoate is improved. On the one hand, sodium dodecyl sulfate is introduced to activate the surface of bismuth isooctanoate, so that subsequent organic tertiary amines can better modify it, enrich its surface functional groups, and improve catalytic performance. On the other hand, the introduction of metavanadate ions during the synthesis process can significantly improve the selectivity of the catalyst and inhibit the generation of byproducts.

[0022] 2. The composite polyurethane catalyst prepared by the present invention is not only safe and environmentally friendly, but also has a selectivity of more than 90% in the process of catalyzing the condensation reaction of polyols and polyisocyanates to generate polyurethane, with few by-products and high polyurethane yield. The prepared polyurethane has excellent mechanical properties and is suitable for wide industrial application. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in combination with specific embodiments and comparative examples.

[0024] Example 1

[0025] This embodiment provides a composite polyurethane catalyst, and the preparation method is as follows:

[0026] S1: dissolving 4.85 g of bismuth nitrate pentahydrate in 50 mL of nitric acid solution having a concentration of 2 mol / L to form solution A;

[0027] S2: dissolving isooctanoic acid, sodium metavanadate and sodium dodecyl sulfate in isopropanol; isooctanoic acid, sodium metavanadate, sodium dodecyl sulfate and isopropanol are mixed in a ratio of 0.03 mol: 0.001 mol: 0.005 mol: 50 mL, and stirred thoroughly to obtain solution B;

[0028] S3: Solution A and Solution B were mixed, stirred at 80° C. for 6 h, and then placed in a high-pressure reactor for a solvothermal reaction at a solvothermal reaction temperature of 160° C. for 8 h to obtain a precursor;

[0029] S4: 5 g of triethylamine and 50 mL of isopropanol were mixed to form solution C;

[0030] S5: Disperse 5 g of the precursor in 50 mL of solution C, stir at 80° C. for 8 h for modification, and then wash and filter to obtain a composite polyurethane catalyst.

[0031] Example 2

[0032] This embodiment provides a composite polyurethane catalyst, and the preparation method is as follows:

[0033] S1: dissolving 4.85 g of bismuth nitrate pentahydrate in 80 mL of nitric acid solution having a concentration of 1 mol / L to form solution A;

[0034] S2: dissolving isooctanoic acid, sodium metavanadate and sodium dodecyl sulfate in isopropanol; isooctanoic acid, sodium metavanadate, sodium dodecyl sulfate and isopropanol are mixed in a ratio of 0.03 mol: 0.001 mol: 0.005 mol: 50 mL, and stirred thoroughly to obtain solution B;

[0035] S3: Solution A and solution B were mixed, stirred at 90° C. for 3 h, and then placed in a high-pressure reactor for solvothermal reaction at a solvothermal reaction temperature of 180° C. for 8 h to obtain a precursor;

[0036] S4: 5.6 g of triethylenediamine and 50 mL of isopropanol were mixed to form solution C;

[0037] S5: 8 g of the precursor was dispersed in 50 mL of solution C, and the mixture was stirred at 90° C. for 5 h for modification, and then washed and filtered to obtain a composite polyurethane catalyst.

[0038] Example 3

[0039] This embodiment provides a composite polyurethane catalyst, and the preparation method is as follows:

[0040] S1: dissolving 3.86 g of bismuth acetate in 50 mL of nitric acid solution having a concentration of 2 mol / L to form solution A;

[0041] S2: dissolving isooctanoic acid, sodium metavanadate and sodium dodecyl sulfate in isopropanol; isooctanoic acid, sodium metavanadate, sodium dodecyl sulfate and isopropanol are mixed in a ratio of 0.03 mol: 0.001 mol: 0.005 mol: 80 mL, and stirred thoroughly to obtain solution B;

[0042] S3: Solution A and solution B were mixed, stirred at 90° C. for 3 h, and then placed in a high-pressure reactor for solvothermal reaction at a solvothermal reaction temperature of 160° C. for 10 h to obtain a precursor;

[0043] S4: 5.76 g of N-ethylmorpholine and 30 mL of isopropanol were mixed to form solution C;

[0044] S5: Disperse 5 g of the precursor in 30 mL of solution C, stir at 90° C. for 5 h for modification, and then wash and filter to obtain a composite polyurethane catalyst.

[0045] Example 4

[0046] This embodiment provides a composite polyurethane catalyst, and the preparation method is as follows:

[0047] S1: dissolving 3.86 g of bismuth acetate in 80 mL of 2 mol / L nitric acid solution to form solution A;

[0048] S2: dissolving isooctanoic acid, sodium metavanadate and sodium dodecyl sulfate in isopropanol; isooctanoic acid, sodium metavanadate, sodium dodecyl sulfate and isopropanol are mixed in a ratio of 0.03 mol: 0.001 mol: 0.005 mol: 80 mL, and stirred thoroughly to obtain solution B;

[0049] S3: Solution A and solution B were mixed, stirred at 80° C. for 6 h, and then placed in a high-pressure reactor for solvothermal reaction at a solvothermal reaction temperature of 160° C. for 10 h to obtain a precursor;

[0050] S4: 5.6 g of triethylenediamine and 50 mL of isopropanol were mixed to form solution C;

[0051] S5: Disperse 5 g of the precursor in 50 mL of solution C, stir at 80° C. for 5 h for modification, and then wash and filter to obtain a composite polyurethane catalyst.

[0052] Example 5

[0053] This embodiment provides a composite polyurethane catalyst, and the preparation method is as follows:

[0054] S1: dissolving 4.85 g of bismuth nitrate pentahydrate in 50 mL of nitric acid solution having a concentration of 1.5 mol / L to form solution A;

[0055] S2: dissolving isooctanoic acid, sodium metavanadate and sodium dodecyl sulfate in isopropanol; isooctanoic acid, sodium metavanadate, sodium dodecyl sulfate and isopropanol are mixed in a ratio of 0.03 mol: 0.001 mol: 0.005 mol: 50 mL, and stirred thoroughly to obtain solution B;

[0056] S3: Solution A and solution B were mixed, stirred at 90° C. for 4 h, and then placed in a high-pressure reactor for solvothermal reaction at a solvothermal reaction temperature of 180° C. for 10 h to obtain a precursor;

[0057] S4: 4.46 g of N,N-dimethylethanolamine and 50 mL of isopropanol were mixed to form solution C;

[0058] S5: Disperse 5 g of the precursor in 50 mL of solution C, stir at 90° C. for 6 h for modification, and then wash and filter to obtain a composite polyurethane catalyst.

[0059] Comparative Example 1

[0060] This comparative example provides a composite polyurethane catalyst, the preparation method of which is:

[0061] S1: dissolving 4.85 g of bismuth nitrate pentahydrate in 50 mL of nitric acid solution having a concentration of 2 mol / L to form solution A;

[0062] S2: dissolving isooctanoic acid and sodium dodecyl sulfate in isopropanol; isooctanoic acid, sodium dodecyl sulfate and isopropanol are mixed in a ratio of 0.03 mol: 0.005 mol: 50 mL, and stirred thoroughly to obtain solution B;

[0063] S3: Solution A and solution B are mixed, stirred at 80° C. for 6 h, and then placed in a high-pressure reactor for solvent thermal reaction. The solvent thermal reaction temperature is 160° C. and the reaction time is 8 h. The mixture is then washed and filtered to obtain a composite polyurethane catalyst.

[0064] Comparative Example 2

[0065] This comparative example provides a composite polyurethane catalyst, the preparation method of which is:

[0066] S1: dissolving 4.85 g of bismuth nitrate pentahydrate in 50 mL of nitric acid solution having a concentration of 2 mol / L to form solution A;

[0067] S2: dissolving isooctanoic acid, sodium metavanadate and sodium dodecyl sulfate in isopropanol; isooctanoic acid, sodium metavanadate, sodium dodecyl sulfate and isopropanol are mixed in a ratio of 0.03 mol: 0.001 mol: 0.005 mol: 50 mL, and stirred thoroughly to obtain solution B;

[0068] S3: Solution A and solution B are mixed, stirred at 80° C. for 6 h, and then placed in a high-pressure reactor for solvent thermal reaction. The solvent thermal reaction temperature is 160° C. and the reaction time is 8 h. The mixture is then washed and filtered to obtain a composite polyurethane catalyst.

[0069] Performance Test:

[0070] The present invention uses polyethylene adipate and isophorone diisocyanate as raw materials, and mixes them in a molar ratio of -OH group of polyethylene adipate and -NCO group of isophorone diisocyanate of 1:1. During the mixing process, the catalysts prepared in Examples 1 to 5 and Comparative Examples 1 and 2 are added respectively (the catalyst addition amount is 0.3% of the mass of the raw materials) to react to obtain polyurethane. The reaction results are shown in Table 1:

[0071] Table 1

[0072] sample Polyurethane selectivity (%) Example 1 95.67 Example 2 94.73 Example 3 95.24 Example 4 92.77 Example 5 94.05 Comparative Example 1 82.82 Comparative Example 2 90.16

[0073] After the above reaction raw materials and catalyst are fully stirred and mixed, they are poured into a mold and cured at room temperature to form a film. The tensile strength and elongation at break of the polyurethane film are tested according to the national standard GB / T 2567-2008. The results are shown in Table 2:

[0074] Table 2

[0075] sample Tensile strength(MPa) Elongation at break (%) Example 1 4.36 248 Example 2 4.43 256 Example 3 4.22 252 Example 4 4.37 250 Example 5 4.41 245 Comparative Example 1 3.23 184 Comparative Example 2 4.02 227

Claims

1. A method for preparing a composite polyurethane catalyst, characterized in that: The steps include: S1: dissolving a bismuth salt in a nitric acid solution to form a solution A; S2: dissolving isooctanoic acid, sodium metavanadate and sodium dodecyl sulfate in isopropanol and stirring thoroughly to obtain solution B; S3: mixing solution A and solution B, stirring and mixing them evenly, and placing them in a high-pressure reactor for solvothermal reaction to obtain a precursor; S4: mixing an organic tertiary amine and isopropanol to form a solution C; S5: dispersing the precursor in solution C, fully modifying it under heating conditions, and then washing and filtering to obtain a composite polyurethane catalyst; In step S1, the bismuth salt is at least one of bismuth nitrate pentahydrate and bismuth acetate; In step S4, the organic tertiary amine is triethylamine, triethylenediamine, N-ethylmorpholine or N,N-dimethylethanolamine.

2. The method for preparing a composite polyurethane catalyst according to claim 1, characterized in that: In step S1, the concentration of the nitric acid solution is 1-2 mol / L, and the addition ratio of the bismuth salt to the nitric acid solution is 0.01 mol:50-80 mL.

3. The method for preparing a composite polyurethane catalyst according to claim 1, characterized in that: The ratio of bismuth salt, isooctanoic acid, sodium metavanadate, sodium dodecylsulfonate and isopropanol is 0.01 mol: 0.03 mol: 0.001 mol: 0.005 mol: 50~80 mL.

4. The method for preparing a composite polyurethane catalyst according to claim 1, characterized in that: In step S3, a solvothermal reaction is carried out after stirring at 80-90° C. for 3-6 hours; the solvothermal reaction temperature is 160-180° C., and the reaction time is 8-10 hours.

5. The method for preparing a composite polyurethane catalyst according to claim 1, characterized in that: In step S4, the addition ratio of the organic tertiary amine and isopropanol is 0.05 mol:30-50 mL.

6. The method for preparing a composite polyurethane catalyst according to claim 1, characterized in that: In step S5, the addition ratio of the precursor to solution C is 5-8 g:30-50 mL.

7. The method for preparing a composite polyurethane catalyst according to claim 1, characterized in that: In step S5, the modification is carried out by stirring at 80-90° C. for 5-8 hours.

8. The composite polyurethane catalyst prepared by the method for preparing the composite polyurethane catalyst according to any one of claims 1 to 7.