Preparation method and application of environment-friendly thermosensitive metal organic catalyst

Abstract

The invention relates to the field of catalysts, and particularly discloses a preparation method and application of an environment-friendly thermosensitive metal organic catalyst, the molecular structure of the catalyst contains two metal centers and related steric hindrance and thermosensitive groups, so that the catalyst can delay the catalysis of active groups at the initial stage and accelerate the post-curing rate at the same time; and after being mixed with a polyurethane IP material, the material has good fluidity, is easy to cast and quick to demould, and improves the quality of a polyurethane product.

Description

Technical Field

[0001] The present invention belongs to the field of catalysts, and particularly relates to a preparation method and application of an environmentally friendly thermosensitive metal-organic catalyst. Background Art

[0002] Organometallic catalysts are widely used in the preparation of polyurethane foams, elastomers, adhesives, coatings, sealants, waterproof coatings and paving materials. They mainly include compounds such as organotin, organobismuth and organolead. Among them, organotin catalysts are mainly used for the gel reaction of polyurethanes. However, the targeting selectivity of organotin for the reaction of isocyanate with polyol and water is not obvious, resulting in many bubbles in the finished product and a high production defect rate. Moreover, organotin is highly toxic and is restricted in many fields. Organobismuth catalysts are a relatively new type of catalysts, which have low biological toxicity and can be used as substitutes for organotin. However, their targeting selectivity for the reaction of isocyanate with polyol and water is still not obvious, and the catalytic activity in the later stage of the reaction is insufficient, resulting in slow product molding. Organolead catalysts have been restricted in some fields due to their potential harm to the human body. The above-mentioned several types of catalysts have certain environmental protection and product quality problems in the synthesis of polyurethanes. In order to reduce the bubbles in polyurethane products, Patent CN113292692B provides a polyurethane-reactive organometallic catalyst with two metal centers through the coordination reaction of Schiff base imine ligands and metal carboxylates. This organometallic catalyst does not contain highly toxic heavy metals and can inhibit the reaction of isocyanate with trace moisture, making the obtained polyurethane products have fast molding, transparency, non-foaming and high hardness. Another example is Patent CN109575211B, which provides a low-polymer coordination hybrid organometallic catalyst through the reaction of metallocene acid and inorganic metal salts. The catalytic activity of this catalyst for the reaction of moisture and isocyanate is very low, reducing the bubbles in polyurethane products.

[0003] Analysis from the reaction mechanism shows that in the polyurethane reaction, the reaction of isocyanate with trace moisture will consume a large amount of isocyanate, affecting the synthesis of polyurethanes and the performance of the final products. Moreover, the reaction of isocyanate with water will generate carbon dioxide gas, resulting in the formation of bubbles in polyurethane products. It can be seen that the above patents all achieve the effect of reducing bubbles by inhibiting the catalytic activity of the reaction between moisture and isocyanate. Although water will produce insoluble gels, the presence of trace water can also play a chain extension role for polyurethane prepolymers. In order to reduce the impact on the synthesis of polyurethanes itself, the present invention provides an organometallic catalyst with a delayed catalytic reaction for active groups in the initial stage. This catalyst has a thermosensitive delay for the reaction of polyurethanes. At the initial stage of material mixing, the reaction does not occur, and the viscosity rises slowly, which is beneficial to material flow and mold filling. When the material is heated to a specific temperature point, the catalytic activity is rapidly released, catalyzing the rapid molding and demolding of the material. Summary of the Invention

[0004] To overcome the deficiencies of the above-mentioned existing technologies, the present invention provides an environmentally friendly, hydrolysis-resistant, acid-resistant, and alkali-resistant organometallic catalyst. The molecular structure of this catalyst contains 2 metal centers, and the relevant groups play roles such as delaying reactions and resisting hydrolysis through steric hindrance and thermosensitivity, enabling the catalyst to delay the catalysis of active groups in the initial stage while accelerating the post-curing rate, thereby prolonging the flow time of the polyurethane resin in the mold and accelerating the catalytic molding of the polyurethane material.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] On the one hand, the present invention provides a preparation method of an environmentally friendly thermosensitive organometallic catalyst, which specifically includes the following steps:

[0007] S1. At 50 - 70 °C, stir triphenylchloromethane and p-tert-butylphenol for 8 - 12 h, cool to room temperature, wash, filter to obtain a white solid mixture, and then perform recrystallization to obtain reactant 1;

[0008] S2. Dissolve reactant 1 in DMF, then add NBS dissolved in DMF. After the addition is complete, stir in the dark at room temperature for 40 - 60 h, extract, and perform recrystallization to obtain reactant 2;

[0009] S3. Dissolve reactant 2 in ether under nitrogen protection, add a n-butyllithium hexane solution at -70 - -50 °C, raise the temperature to room temperature at a rate of 4 - 10 °C / min, stir at room temperature for 2 - 5 h, then add tetramethylcyclopentenone at -20 - -5 °C, raise the temperature to room temperature, and stir for 24 - 36 h. Quench the reaction, collect the organic phase, perform rotary evaporation, and recrystallize to obtain reactant 3;

[0010] S4. Dissolve reactant 3 and metal chloride in toluene respectively under nitrogen protection to obtain solution 1 and solution 2. Add solution 1 to solution 2 in 4 - 8 batches at room temperature, raise the temperature to 60 - 80 °C and stir for 1 - 3 h. After completion, perform rotary evaporation, wash to obtain reactant 4;

[0011] S5. Stir metal nitrate, 1H-indol-4-ylmethanol evenly in DMF, add triethylamine and hexane, stir at room temperature for 30 - 50 h, collect the powder, wash with DMF, perform recrystallization, and vacuum dry to constant weight to obtain reactant 5;

[0012] S6. Stir reactant 4, reactant 5, NMP, potassium carbonate, and toluene at 60 - 80 °C for 3 - 7 h, perform rotary evaporation, and recrystallize to obtain the environmentally friendly thermosensitive organometallic catalyst shown in formula (1) or formula (2),

[0013]

[0014] Wherein, or H;

[0015] R2 = H or

[0016] R3 = Cl or

[0017] Me1 is selected from the following metal ions: Ti, Fe, Cr or Mn;

[0018] Me2 is selected from the following metal ions: Zn, Ni, Mg or Mn.

[0019] The organometallic catalyst provided by the present invention is non-toxic and environmentally friendly. During its preparation process, by introducing large structural groups such as triphenylmethyl and tert-butyl through reactant 1, more space can be occupied during the polyurethane synthesis process, hindering the approach between hydroxyl groups and isocyanates; and it brings a steric hindrance effect to the catalyst, preventing other molecules from approaching the metal center, thereby affecting the catalytic activity. The combination of the two reduces the initial reaction rate. In addition, the heterocyclic structure introduced by reactant 5 has thermosensitivity and can provide better control of the reaction process during polyurethane synthesis

[0020] In some embodiments, in step S1, the molar ratio of triphenylmethyl chloride to p-tert-butylphenol is (0.3 - 0.6):1.

[0021] In some embodiments, in step S2, the molar ratio of reactant 1 to NBS is 1:(0.9 - 1.2).

[0022] In some embodiments, in step S3, the molar ratio of reactant 2 to tetramethylcyclopentenone is 1:(1.0 - 1.3).

[0023] In some embodiments, in step S4, the molar ratio of reactant 3 to metal chloride is 1:(0.9 - 1.2).

[0024] In some embodiments, in step S5, the molar ratio of metal nitrate to 1H-indol-4-ylmethanol is 1:(1.0 - 1.2).

[0025] In some embodiments, in step S6, the molar ratio of reactant 4 to reactant 5 is 1:(1.5 - 2.2).

[0026] On the other hand, the present invention provides the application of the environmentally friendly and thermosensitive organometallic catalyst obtained by the above preparation method in the synthesis of polyurethane resin.

[0027] In some embodiments, the polyurethane resin comprises an independent I prefabricated component and an independent P prefabricated component, and the preparation steps of the independent I prefabricated component and the independent P prefabricated component are as follows: reacting a polyol and a diisocyanate at 60-100 °C for 1-5 h to obtain the independent I prefabricated component; mixing the polyol, a chain extender and the environmentally friendly thermosensitive organometallic catalyst to obtain the independent P prefabricated component.

[0028] In some embodiments, the polyol comprises at least one of a polyether polyol having a molecular weight of 400-5000 or a polyester polyol having a molecular weight of 1000-3000.

[0029] In some embodiments, the polyester polyol comprises one or more of polycaprolactone diol, ethylene glycol adipate, hexanediol adipate, and diethylene glycol adipate.

[0030] In some embodiments, the polyether polyol comprises one or more of polytetrahydrofuran diol and polypropylene glycol.

[0031] In some embodiments, the chain extender comprises one or more of dichlorodiphenylmethane, diethyltoluenediamine, dimethylthiotoluenediamine, 1,4-butanediol, and 1,6-hexanediol.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. The present invention provides an environmentally friendly, hydrolysis-resistant, acid-resistant, and alkali-resistant organometallic catalyst. The molecular structure of the catalyst contains 2 metal centers and related steric hindrance and thermosensitive groups, enabling the catalyst to delay the catalysis of active groups in the initial stage and accelerate the later curing rate. After mixing with polyurethane IP materials, it has good fluidity, is easy to cast, and has fast demolding, improving the quality of polyurethane products.

[0034] 2. During the synthesis of polyurethane, groups with large steric hindrance such as tert-butyl and trityl in the organometallic catalyst provided by the present invention can prevent other molecules from approaching the metal center. At the same time, the steric hindrance effect can also hinder the approach between hydroxyl groups and isocyanates, delaying the reaction rate between isocyanates and hydroxyl groups in the initial stage. In addition, the heterocycle contained in the molecular structure has thermosensitivity, facilitating the process control of the reaction process. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is the NMR diagram of catalyst X1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] The present invention will be described below in conjunction with specific implementation examples. It should be noted that the following examples are examples of the present invention, only for explaining the present invention, and not for limiting the present invention. Other combinations and various improvements within the concept of the present invention can be made without departing from the gist or scope of the present invention.

[0037] It should be noted that the raw materials used in the following preparation examples and examples are from any commercially available manufacturer if not specifically stated; the operations such as dissolution, recrystallization, extraction, rotary evaporation, quenching, and drying are conventional technical operations in the art and can be selected by relevant technical personnel.

[0038] It should be noted that the structures of the catalysts X1 - X5 obtained in the following Examples 1 - 5 are included in the structures shown in Formula (1) or Formula (2).

[0039] Example 1

[0040] A preparation method of an environmentally friendly thermosensitive metal - organic catalyst comprises the following steps:

[0041] S1. At 60 °C, 0.44 mol of triphenylchloromethane and 1 mol of p - tert - butylphenol are stirred for 10 h, cooled to room temperature, washed, filtered to obtain a white solid mixture, and then recrystallized to obtain Reactant 1;

[0042] S2. 1 mol of Reactant 1 is dissolved in DMF, and then 1.1 mol of NBS dissolved in DMF is added. After the addition is complete, it is stirred for 40 - 60 h at room temperature in the dark, extracted, and recrystallized to obtain Reactant 2;

[0043] S3. 1 mol of Reactant 2 is dissolved in diethyl ether under nitrogen protection, and 1.18 L of a 1.77 mol / L n - butyllithium hexane solution is added at - 60 °C. It is heated to room temperature at a rate of 6 °C / min, stirred at room temperature for 3 h, then 1.15 mol of tetramethylcyclopentenone is added at - 10 °C, heated to room temperature, and stirred for 30 h. The reaction is quenched, the organic phase is collected, rotary evaporated, and recrystallized to obtain Reactant 3;

[0044] S4. 1 mol of Reactant 3 and 1.1 mol of titanium tetrachloride are respectively dissolved in toluene under nitrogen protection to obtain Solution 1 and Solution 2. At room temperature, Solution 1 is added to Solution 2 in 6 batches, heated to 70 °C and stirred for 2 h. After completion, it is rotary evaporated and washed to obtain Reactant 4;

[0045] S5. 1 mol of zinc nitrate, 1.1 mol of 1H - indol - 4 - yl methanol are stirred evenly in DMF, 10 L of triethylamine and 50 L of hexane are added, and it is stirred at room temperature for 40 h. The powder is collected, washed with DMF, recrystallized, and vacuum - dried to constant weight to obtain Reactant 5;

[0046] S6. Stir 1 mol of reactant 4, 2 mol of reactant 5, 12 L of NMP, 0.01 mol of potassium carbonate and 1 L of toluene at 70 °C for 5 h, rotary evaporate, and recrystallize to obtain catalyst X1. The structural formula is as follows. The NMR test results of catalyst X1 are shown in Figure 1 ;

[0047]

[0048] Example 2

[0049] This example provides a preparation method of an environmentally friendly thermosensitive metal-organic catalyst. The specific implementation method is the same as that of Example 1, except that in step S4, titanium tetrachloride is replaced by ferric chloride with the same molar amount to obtain catalyst X2.

[0050] Example 3

[0051] This example provides a preparation method of an environmentally friendly thermosensitive metal-organic catalyst. The specific implementation method is the same as that of Example 1, except that in step S4, titanium tetrachloride is replaced by chromium trichloride with the same molar amount to obtain catalyst X3.

[0052] Example 4

[0053] This example provides a preparation method of an environmentally friendly thermosensitive metal-organic catalyst. The specific implementation method is the same as that of Example 1, except that in step S5, zinc nitrate is replaced by nickel nitrate with the same molar amount to obtain catalyst X4.

[0054] Example 5

[0055] This example provides a preparation method of an environmentally friendly thermosensitive metal-organic catalyst. The specific implementation method is the same as that of Example 1, except that in step S5, zinc nitrate is replaced by manganese nitrate with the same molar amount to obtain catalyst X5.

[0056] Example 6

[0057] This example provides an application of an environmentally friendly thermosensitive metal-organic catalyst:

[0058] React 76.74 g of polyether polyol with a molecular weight of 2000 and a functionality of 2 and 23.26 g of toluene diisocyanate (TDI-80) at 85 °C for 2 h, vacuum degas and then discharge and cool to obtain the independent I prefabricated component;

[0059] Mix 42.1 g of polyether polyol with a molecular weight of 3000 and a functionality of 3 and 18.04 g of MOCA evenly. After vacuum dehydrating and cooling, add 0.18 g of catalyst X1 dissolved in 20 mL of ethyl acetate to obtain the independent P prefabricated component.

[0060] Example 7

[0061] This embodiment provides an application of an environmentally friendly thermosensitive metal-organic catalyst:

[0062] 70 g of polyether polyol with a molecular weight of 2000 and a functionality of 2 and 30 g of diphenylmethane diisocyanate (MDI50) were reacted at 75 °C for 2 h. After vacuum degassing, the mixture was discharged and cooled to obtain the independent I prefabricated component;

[0063] 37.54 g of polyether polyol with a molecular weight of 3000 and a functionality of 3 and 16.09 g of MOCA were mixed evenly. After vacuum dehydration and temperature reduction, 0.16 g of catalyst X2 dissolved in 20 mL of ethyl acetate was added to obtain the independent P prefabricated component.

[0064] Example 8

[0065] This embodiment provides an application of an environmentally friendly thermosensitive metal-organic catalyst:

[0066] 79.5 g of polytetrahydrofuran ether polyol with a molecular weight of 2000 and a functionality of 2 and 20.5 g of toluene diisocyanate (TDI-80) were reacted at 85 °C for 2 h. After vacuum degassing, the mixture was discharged and cooled to obtain the independent I prefabricated component;

[0067] 56.1 g of polytetrahydrofuran ether polyol with a molecular weight of 2000 and a functionality of 2 and 12.32 g of MOCA were mixed evenly. After vacuum dehydration and temperature reduction, 0.13 g of catalyst X3 dissolved in 20 mL of ethyl acetate was added to obtain the independent P prefabricated component.

[0068] Example 9

[0069] This embodiment provides an application of an environmentally friendly thermosensitive metal-organic catalyst:

[0070] 58 g of isophorone diisocyanate (IPDI) and 42 g of polyether polyol with a molecular weight of 2000 and a functionality of 2 were reacted at 90 °C for 2 h. After vacuum degassing, the mixture was discharged and cooled to obtain the independent I prefabricated component;

[0071] 108 g of polytetrahydrofuran ether polyol with a molecular weight of 2000 and a functionality of 2 and 46.29 g of MOCA were mixed evenly. After vacuum dehydration and temperature reduction, 0.13 g of catalyst X4 dissolved in 20 mL of ethyl acetate was added to obtain the independent P prefabricated component.

[0072] Example 10

[0073] This embodiment provides an application of an environmentally friendly thermosensitive metal-organic catalyst:

[0074] 58 g of isophorone diisocyanate (IPDI) and 42 g of a polyether polyol with a functionality of 2 and a molecular weight of 2000 were reacted at 90 °C for 2 h. After vacuum degassing, the mixture was discharged and cooled to obtain the independent I prefabricated component;

[0075] 23.4 g of a polyether polyol with a functionality of 2 and a molecular weight of 2000 and 54.6 g of a polyether polyol with a functionality of 3 and a hydroxyl value of 465 were mixed evenly. After vacuum dehydration and cooling, 0.25 g of catalyst X5 dissolved in 20 mL of ethyl acetate was added to obtain the independent P prefabricated component.

[0076] Example 11

[0077] This example provides an application of an environmentally friendly thermosensitive metal-organic catalyst. The specific implementation method is the same as that of Example 6, except that catalyst X1 is replaced by an equal amount of catalyst X6.

[0078] Comparative Example 1

[0079] This comparative example provides an application of an organometallic catalyst. The difference from Example 6 is that:

[0080] Catalyst X1 is replaced by an equal amount of dibutyltin dilaurate.

[0081] Comparative Example 2

[0082] This comparative example provides an application of an organometallic catalyst. The difference from Example 6 is that:

[0083] Catalyst X1 is replaced by an equal amount of bismuth neodecanoate.

[0084] Comparative Example 3

[0085] This comparative example provides a preparation method of an environmentally friendly thermosensitive metal-organic catalyst, which includes the following steps:

[0086] S1. At 60 °C, 0.44 mol of triphenylchloromethane and 1 mol of p-tert-butylphenol were stirred for 10 h, cooled to room temperature, washed, filtered to obtain a white solid mixture, and then recrystallized to obtain Reactant 1;

[0087] S2. 1 mol of Reactant 1 was dissolved in DMF, and then 1.1 mol of NBS dissolved in DMF was added. After the addition was complete, the mixture was stirred at room temperature in the dark for 40 - 60 h, extracted, and recrystallized to obtain Reactant 2;

[0088] S3. Dissolve 1 mol of reactant 2 in diethyl ether under nitrogen protection, add 1.18 L of a 1.77 mol / L n-butyllithium hexane solution at -60°C, raise the temperature to room temperature at a rate of 6°C / min, stir at room temperature for 3 h, then add 1.15 mol of tetramethylcyclopentenone at -10°C, raise the temperature to room temperature, stir for 30 h, quench the reaction, collect the organic phase, rotary evaporate, and recrystallize to obtain reactant 3;

[0089] S4. Dissolve 1 mol of reactant 3 and 1.1 mol of titanium tetrachloride in toluene respectively under nitrogen protection to obtain solution 1 and solution 2. Add solution 1 to solution 2 in 6 batches at room temperature, raise the temperature to 70°C and stir for 2 h. After completion, rotary evaporate and wash to obtain catalyst X6.

[0090] Performance test:

[0091] 1. Conduct inductively coupled plasma emission (ICP) tests on catalysts X1 - X6. The instrument uses a VISTA-MPX inductively coupled plasma emission spectrometer from Varian, USA. The wavelength range continuously covers 175 - 785 nm, the RF generator frequency is 40.68 MHz. The operation is as follows: Weigh 0.1 g of the sample, add 10 ml of perchloric acid, heat for digestion, dilute to 100 ml with 2 wt% HCl, measure the characteristic peak intensity of metal elements, and calculate the metal element content (W%). The results are shown in Table 1.

[0092] Table 1

[0093]

[0094] 2. Mix the prefabricated components provided in Examples 6 - 11 and Comparative Examples 1 - 2, observe the curing formation process, and conduct transmittance tests and mechanical tests on the formed polyurethane (cured at 80°C). The specific parameters are shown in Table 2.

[0095] Table 2

[0096]

[0097]

[0098] As can be seen from Table 1, the corresponding metal elements have been loaded onto the catalysts X1 to X6, indicating the feasibility of the catalyst synthesis method of the present invention. From the data in Table 2, it can be seen that compared with the single-metal center catalyst X6 used in Example 11, the polyurethanes obtained in Examples 6 to 10 using the catalysts X1 to X5 respectively have good light transmittance, indicating that the dual-metal center organic catalyst provided by the present invention has strong targeted catalytic properties and has similar catalytic effects when having different metal centers, with a wide range of applicability. Combining the gel time and curing time at 80°C, it can be seen that the gel time at 80°C of the catalysts X1 to X5 appears relatively late, indicating that the dual-metal center catalyst provided by the present invention can delay the catalysis of active groups in the initial stage, thereby extending the flow time of the polyurethane resin in the mold. And from the time difference between the appearance of the gel and the curing state, it can be seen that once the dual-metal center catalyst provided by the present invention activates the active groups, it can effectively accelerate the curing speed. Combining the mechanical test results in Table 2, it can be seen that compared with dibutyltin dilaurate and bismuth neodecanoate as catalysts, the polyurethanes obtained with the dual-metal center catalyst provided in this application have higher hardness and tensile fracture strength, indicating that this characteristic of delaying activity in the initial stage and accelerating curing in the later stage can enhance the quality of the polyurethane.

[0099] Compared with Example 1, in Comparative Examples 1 and 2, dibutyltin dilaurate and bismuth neodecanoate were used as catalysts respectively, and the obtained polyurethanes had lower light transmittance. Combining the gel time at 80°C, it can be seen that these two types of catalysts always maintained a relatively fast activation efficiency during the curing process. Although the curing time was less, it was not conducive to improving the quality of the polyurethane material. Further, combining the curing times at 40°C and 60°C in Examples 6 to 11 in Table 2, it can be seen that the dual-metal center catalyst of this application can officially take effect at 40°C. At the same time, the change range of the curing time decreasing with the increase in temperature indicates its high thermal sensitivity, and the thermal sensitivity of the dual-metal center catalyst is higher than that of the single-metal center catalyst.

[0100] The above-described examples and comparative examples do not impose any formal restrictions on the present invention. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art, without departing from the scope of the technical solution of the present invention, may make some changes or modifications to the above-disclosed technical content to obtain equivalent embodiments with equivalent changes. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A preparation method of an environmentally friendly thermosensitive metal-organic catalyst, characterized in that, Specifically, it includes the following steps: S1. At 50 - 70 °C, stir triphenylchloromethane and p-tert-butylphenol for 8 - 12 h, cool to room temperature, wash, filter to obtain a white solid mixture, and then perform recrystallization to obtain reactant 1; S2. Dissolve reactant 1 in DMF, then add NBS dissolved in DMF. After dropping, stir in the dark at room temperature for 40 - 60 h, extract, and perform recrystallization to obtain reactant 2; S3. Dissolve reactant 2 in ether under nitrogen protection, add n-butyllithium hexane solution at -70 - -50 °C, raise the temperature to room temperature at a rate of 4 - 10 °C / min, stir at room temperature for 2 - 5 h, then add tetramethylcyclopentenone at -20 - -5 °C, raise the temperature to room temperature, and stir for 24 - 36 h to quench the reaction, collect the organic phase, rotary evaporate, and perform recrystallization to obtain reactant 3; S4. Dissolve reactant 3 and metal chloride salt in toluene respectively under nitrogen protection to obtain solution 1 and solution 2. Add solution 1 to solution 2 in 4 - 8 batches at room temperature, raise the temperature to 60 - 80 °C and stir for 1 - 3 h. After completion, rotary evaporate, wash to obtain reactant 4; S5. Stir metal nitrate, 1H-indol-4-ylmethanol evenly in DMF, add triethylamine and hexane, stir at room temperature for 30 - 50 h, collect the powder, wash with DMF, perform recrystallization, and vacuum dry to constant weight to obtain reactant 5; S6. Stir reactant 4, reactant 5, NMP, potassium carbonate and toluene at 60 - 80 °C for 3 - 7 h, rotary evaporate, and perform recrystallization to obtain the environmentally friendly thermosensitive metal-organic catalyst shown in formula (1) or formula (2); wherein, or H; R2 = H or R3 = Cl or Me1 is selected from the following metal ions: Ti, Fe, Cr or Mn; Me2 is selected from the following metal ions: Zn, Ni, Mg or Mn.

2. The preparation method of the environmentally friendly thermosensitive metal-organic catalyst according to claim 1, characterized in that, In step S1, the molar ratio of triphenylchloromethane to p-tert-butylphenol is (0.3 - 0.6):

1.

3. The preparation method of the environmentally friendly thermosensitive metal organic catalyst according to claim 1, characterized in that, In step S2, the molar ratio of reactant 1 to NBS is 1:(0.9 - 1.2).

4. The preparation method of the environmentally friendly thermosensitive metal-organic catalyst according to claim 1, characterized in that, In step S3, the molar ratio of reactant 2 to tetramethylcyclopentenone is 1:(1.0 - 1.3).

5. The preparation method of the environmentally friendly thermosensitive metal-organic catalyst according to claim 1, wherein, In step S4, the molar ratio of reactant 3 to metal chloride salt is 1:(0.9 - 1.2).

6. The preparation method of the environmentally friendly thermosensitive metal-organic catalyst according to claim 1, wherein, In step S5, the molar ratio of metal nitrate to 1H-indol-4-ylmethanol is 1:(1.0 - 1.2).

7. The preparation method of the environmentally friendly thermosensitive metal-organic catalyst according to claim 1, wherein, In step S6, the molar ratio of reactant 4 to reactant 5 is 1:(1.5 - 2.2).

8. Application of the environmentally friendly thermosensitive metal-organic catalyst obtained by the preparation method according to any one of claims 1 - 7 in the synthesis of polyurethane resin.

9. Use of the environmentally friendly thermosensitive metal-organic catalyst according to claim 8 in the synthesis of polyurethane resin, characterized in that, The polyurethane resin includes independent I prefabricated component and independent P prefabricated component. The preparation steps of the independent I prefabricated component and the independent P prefabricated component are as follows: React polyol and diisocyanate at 60 - 100 °C for 1 - 5 h to obtain the independent I prefabricated component; Mix polyol, chain extender and the environmentally friendly thermosensitive metal-organic catalyst to obtain the independent P prefabricated component.

10. The application of the environmentally friendly thermosensitive metal-organic catalyst according to claim 9 in the synthesis of polyurethane resin, characterized in that, The polyol includes at least one of polyether polyol with a molecular weight of 400 - 5000 or polyester polyol with a molecular weight of 1000 - 3000.

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