1,6-pyrene diisocyanate, a method for preparing the same, and application thereof to modified polyurethane elastomers

Abstract

This invention discloses a 1,6-pyrene diisocyanate, obtained by nitrification of pyrene to obtain a nitrated product, which is then reduced to an amino group and subsequently subjected to a carbonylation reaction. Based on the same inventive concept, this invention also provides a method for preparing 1,6-pyrene diisocyanate, which has a simple process and a yield greater than 30%. Based on the same inventive concept, this invention also provides a polyurethane foam composition. Furthermore, this invention provides the application of 1,6-pyrene diisocyanate as a polyurethane block in polyurethane rubber and elastomers, high-strength foam materials, polyurethane fibers, cast polyurethane rubber, polyurethane emulsions and coatings, adhesives, and shock-absorbing and damping foam materials. The polyurethane materials prepared from the 1,6-pyrene diisocyanate provided by this invention have advantages such as high temperature resistance, solvent resistance, friction resistance, and high impact resistance; they also improve the modulus properties and high-temperature fatigue resistance of polyurethane elastomer microporous foam materials under high-temperature conditions.

Description

Technical Field

[0001] This invention belongs to the field of modified polyurethane elastomers, specifically relating to a 1,6-pyrene diisocyanate, its preparation method, and its application in modified polyurethane elastomers. Background Technology

[0002] Polyurethane is typically produced by the reaction of isocyanates and polyols. Isocyanates, as important organic intermediates, are widely used in polyurethane elastomers, high-grade fibers, high-performance adhesives, coatings, waterproofing materials, dust removal materials, and shock absorption damping. Isocyanates, as a partial block structure in polyurethane, play a crucial role in its application areas; their rigidity, structural order, molecular weight, and molecular regularity determine the range of applications for polyurethane. However, under certain high-frequency oscillation conditions or high-temperature conditions, polyurethane exhibits drawbacks such as high internal heat generation, generally poor high-temperature resistance, and poor resistance to strong polar solvents and strong acid / alkali media.

[0003] Therefore, existing technologies urgently need improvement. Summary of the Invention

[0004] The purpose of this invention is to provide a 1,6-pyrene diisocyanate, its preparation method, and its application in modifying polyurethane elastomers, addressing existing polyurethane production technologies. This invention is suitable for preparing polyurethane materials that exhibit advantages such as high-temperature resistance, solvent resistance, friction resistance, and high impact resistance. It can also be used to modify polyurethane materials to improve the modulus, high-temperature fatigue resistance, and wear resistance of polyurethane elastomers, cast polyurethane rubber, and microporous foam materials under high-temperature conditions. When applied to microporous foam materials, it improves the high-temperature damping limit, reduces material density, and extends the material's service life.

[0005] The technical solution of this invention is implemented as follows:

[0006] The first objective of this invention is to provide a 1,6-pyrene diisocyanate, which is prepared by nitrification of pyrene to obtain a nitrated product, and then reducing the nitrated product to an amino group followed by a carbonylation reaction.

[0007] The present invention provides a 1,6-pyrene diisocyanate prepared by nitration of pyrene, followed by reduction to amine without separation and then carbonylation. The prepared 1,6-pyrene diisocyanate is used as a hard segment structure in the synthesis of polyurethane materials.

[0008] The 1,6-pyrene diisocyanate as described above, wherein the pyrene density is 1.27 ± 0.1 g / cm³. 3 It has a melting point of 145–148°C and a molecular weight of 202.251.

[0009] As described above, the 1,6-pyrene diisocyanate uses glacial acetic acid as the solvent in the nitration reaction, with a density of 1.049 g / cm³. 3 The nitration reagent is any one of the following (1)-(3): (1) nitric acid and glacial acetic acid; (2) a mixed solution of nitric acid and sulfuric acid; (3) a mixed solution of nitrate and acetic acid.

[0010] The reduction of the 1,6-pyrene diisocyanate described above is sulfide reduction, hydrogenation reduction, or iron powder reduction. Preferably, the reduction is sulfide reduction.

[0011] As described above, in the 1,6-pyrene diisocyanate, the carbonylating agent in the carbonylation reaction is phosgene or triphosgene.

[0012] A second objective of this invention is to provide a method for preparing 1,6-pyrene diisocyanate, comprising the following steps:

[0013] Step 1: Add glacial acetic acid to pyrene and stir evenly at 80-100℃ to obtain reaction mixture 1; preferably, the mass-to-volume ratio (g:mL) of pyrene to glacial acetic acid in step 1 is (1:1) to (1:20). When the mass-to-volume ratio (g:mL) is greater than 1:1, insufficient glacial acetic acid will cause insufficient dissolution of pyrene, resulting in low reaction yield; when the mass-to-volume ratio (g:mL) is greater than 1:20, excessive acetic acid will result in low production efficiency; more preferably, the mass-to-volume ratio of pyrene to acetic acid in step 1 is (1g:2mL).

[0014] Step 2: Slowly add the nitrification reagent to reaction mixture 1 from Step 1. Stir the resulting yellow suspension at 80–100°C for 0.5–2 hours to obtain reaction mixture 2. Preferably, stir the resulting yellow suspension at 90°C for 1 hour to obtain reaction mixture 2. Preferably, the nitrification reagent in Step 2 is a mixture of nitric acid and glacial acetic acid. More preferably, the volume ratio of nitric acid to glacial acetic acid in Step 2 is (1:2) to (1:5). Most preferably, the volume ratio of nitric acid to glacial acetic acid in Step 2 is (1:2). The reaction temperature in this step helps to improve the reaction rate and product selectivity.

[0015] Step 3: Cool the reaction mixture 2 from Step 2 to room temperature and filter the resulting precipitate. Wash with methanol and dry under vacuum to obtain reaction mixture 3, which is the nitration product. Preferably, the crude nitration product is a mixture containing 1,6-dinitropyrene, 1,8-dinitropyrene, 1,3-dinitropyrene and 1-nitropyrene. This step is a simple and easy-to-operate separation method that can quickly purify and refine the product.

[0016] Step 4: Reduce the reaction mixture 3 obtained in Step 3 to obtain reaction mixture 4;

[0017] For example, in some embodiments of the present invention, the reaction mixture 3 obtained in step three is obtained by sulfide reduction. The reaction mixture 3 obtained in step three is suspended in a mixture of ethanol and NaSH aqueous solution, the solution is heated under reflux for 2-5 hours, and then the entire reaction mixture is cooled to obtain reaction mixture 4. Preferably, the reaction mixture 3 obtained in step three is suspended in a mixture of ethanol and NaSH aqueous solution, the solution is heated under reflux for 3 hours, and then the entire reaction mixture is cooled to obtain reaction mixture 4. The mass concentration of the NaSH aqueous solution is 40%, and the volume to mass ratio of ethanol to NaSH in the ethanol and NaSH aqueous solution is 200 mL: 17.3 g. Step four is preferably sulfide reduction, which has mild reaction conditions, simple operation, and can be used for large-scale production.

[0018] Alternatively, in some embodiments of the present invention, the reaction mixture 3 obtained in step three is subjected to hydrogenation reduction. The nitration product obtained in step three is added to distilled water, sulfuric acid is added, and after purging with nitrogen, a palladium catalyst on carbon is added. Hydrogen is introduced at a flow rate of 50-70 mL / min, and the temperature is raised to 70-90°C to obtain a precipitate. Preferably, the nitration product obtained in step three is added to distilled water, sulfuric acid with a mass percentage of 15% is added, and after purging with nitrogen, a palladium catalyst with a mass fraction of 10% is added. Hydrogen is introduced at a flow rate of 60 mL / min, and the temperature is raised to 80°C to obtain a precipitate.

[0019] Alternatively, in some embodiments of the present invention, the reaction mixture 3 obtained in step three is reduced with iron powder. Iron powder is added to the reaction mixture 3 obtained in step three, the pH is adjusted with ammonium chloride and water, the mixture is heated to 30-50°C and stirred evenly, and then heated to 90-100°C and reacted for 1-2 hours to obtain the reaction mixture 4. Preferably, iron powder is added to the reaction mixture 3 obtained in step three, the pH is adjusted to 5 with 12% ammonium chloride and water, the mixture is heated to 40°C and stirred evenly, and then heated to 95°C and reacted for 1.5 hours to obtain the reaction mixture 4.

[0020] Step 5: The precipitate obtained from the filtered and cooled reaction mixture 4 in Step 4 is dried under vacuum and purified by column chromatography using a gradient elution with a volume ratio of n-hexane to ethyl acetate of (1:1) to (1:3) to obtain reactant 5, namely the yellow solid product 1,6-diaminopyrene; preferably, the volume ratio of n-hexane to ethyl acetate is 1:2; under these conditions, the yield of 1,6-diaminopyrene is 30%-35%. Using a mixture of n-hexane and ethyl acetate as the eluent allows for the recycling of these organic solvents, and this step has the advantages of high efficiency, simplicity, environmental friendliness, resource saving, and high yield.

[0021] Step 6: The product 1,6-diaminopyrene obtained in Step 5 is subjected to phosgenation at 30–60°C with chlorobenzene as a catalyst and phosgene continuously introduced for 2–6 hours to obtain reactant 6; preferably, the product 1,6-diaminopyrene obtained in Step 5 is subjected to phosgenation at 40°C with chlorobenzene as a catalyst and phosgene continuously introduced for 3 hours to obtain reactant 6; this step is simple to operate and has a high conversion rate.

[0022] Step 7: Slowly heat the reactant 6 obtained in Step 6 to 100-150°C and continuously introduce phosgene to carry out a two-stage phosgenation reaction, further converting the amine hydrochloride and acyl chloride intermediates into organic isocyanates, thus obtaining 1,6-pyrene diisocyanate. Preferably, the temperature is slowly increased to 130°C while continuously introducing phosgene for the two-stage phosgenation reaction. This results in a relatively fast initial reaction rate, requiring the temperature to be increased as the reaction progresses to improve the conversion rate. Preferably, the NCO content of the 1,6-pyrene diisocyanate is 28.4%.

[0023] The reaction of the present invention is as follows:

[0024]

[0025]

[0026] The third objective of this invention is to provide a one-step foaming method for preparing polyurethane, comprising the following steps: adding the above-mentioned polyurethane foaming composition into a mold, rapidly stirring and mixing evenly, foaming, curing, and maturing to obtain polyurethane foam.

[0027] A fifth objective of this invention is to provide a method for preparing polyurethane using a prepolymer method, comprising the following steps:

[0028] (1) An excess of the above-mentioned 1,6-pyrene diisocyanate reacts with polypropylene glycol at 95°C to form a prepolymer with a terminal -NCO group content ≤12.0%;

[0029] (2) Casting: The prepolymer and chain extender components are mixed at a mass ratio of 100:10.5. The reaction liquid is injected into the mold and demolded after pre-curing. The chain extender components include the following components in parts by weight: 45 parts of chain extender 1,6-hexanediol, 36 parts of catalyst tetramethylethylenediamine, 14 parts of foaming agent and 5 parts of surfactant.

[0030] (3) Post-curing: After demolding, the product is placed in an oven for curing and left at room temperature for 5 days to obtain polyurethane.

[0031] The sixth objective of this invention is to provide an application of 1,6-pyrene diisocyanate as a polyurethane block in materials such as polyurethane rubber and elastomers, polyurethane fibers, cast polyurethane rubber, polyurethane emulsions and coatings, polyurethane adhesives, and shock-absorbing foams in construction, home furnishings, clothing, medical applications, automotive manufacturing, sporting goods, electronic communications, and aerospace. Experiments have shown that polyurethane prepared using the 1,6-pyrene diisocyanate of this invention via a one-step foaming method exhibits a small constant compression set, good elastic recovery performance, and a large loss factor, indicating rapid energy loss under the same conditions and good shock absorption performance. Furthermore, polyurethane prepared using the 1,6-pyrene diisocyanate of this invention via a prepolymerization method has high tensile strength and tear strength. Its tensile properties change at 70°C for one week after immersion are close to 1, showing good retention and minimal change, indicating that polyurethane prepared using the 1,6-pyrene diisocyanate via a prepolymerization method has high resistance to various media.

[0032] The beneficial effects of this invention are:

[0033] 1. The 1,6-pyrene diisocyanate provided by the present invention comprises a unique tetraphenyl ring connected together by conjugated bonds to form a large conjugated system. It has strong molecular structure stability and high molecular weight and modulus, which makes the polyurethane prepared from it have high elastic modulus, high thermal stability and wear resistance.

[0034] 2. The 1,6-pyrene diisocyanate provided by this invention has the advantage of having a symmetrical and compact molecular structure that forms tight blocks and excellent phase separation in polyurethane. This molecular structure and microphase separation structure enable the prepared polyurethane to have excellent wear resistance, fatigue resistance, and high temperature resistance. In addition, the 1,6-pyrene diisocyanate contains benzene rings, has relatively high chain rigidity, strong intermolecular forces, and a tight molecular spatial arrangement, which helps to prevent the intrusion of media and has high resistance to media.

[0035] 3. The molecular structure of pyrene is usually limited to a planar structure. The per-1,6-pyrene diisocyanate provided by this invention, the reaction of the NCO (isocyanate group) at the 1,6 position with the chain extender and polyol makes this layered structure more diverse in terms of three-dimensional cross-linking structure, thus making the polyurethane prepared therefrom have better mechanical properties.

[0036] 4. 1,6-Pyrene diisocyanate, as an important organic intermediate, will play a crucial role in the future. This invention provides key support for the research and application of high-performance materials. With the increasing market demand for high-end diisocyanates, 1,6-Pyrene diisocyanate will have even broader development prospects. Detailed Implementation

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0038] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0039] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0040] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0041] In the following examples, the pyrene was purchased from Hubei Xindike Chemical Co., Ltd., CAS No.: 129-00-0, with a density of 1.28 g / cm³. 3 Its molecular weight is 202.25.

[0042] The nitric acid was purchased from Maoming Xiongda Chemical Co., Ltd., with a purity of 63%, chloride (Cl) ≤ 0.0001%, and sulfate (SO4) ≤ 0.001%.

[0043] The ethanol was purchased from Shandong Chenyu Chemical Co., Ltd., and its acidity was ≤0.03mmol / 100g.

[0044] The glacial acetic acid was purchased from Sigma-Aldrich (Shanghai) Trading Co., Ltd., and its density was 1.049 g / cm³. 3 .

[0045] The NaHS was purchased from Jinan Huifengda Chemical Co., Ltd., CAS No. 16721-80-5, with a density of 1.79 g / cm³. 3 .

[0046] Example 1:

[0047] This embodiment provides a 1,6-pyrene diisocyanate, the preparation method of which includes the following specific steps:

[0048] Step 1: Add 50 mL of glacial acetic acid to 25 g of pyrene (123.6 mmol) and stir at 90 °C until dissolved to obtain reaction mixture 1;

[0049] Step 2: Slowly add the mixture of 19 mL nitric acid and 50 mL glacial acetic acid to reaction mixture 1. Stir the resulting yellow suspension at 90 °C for 1 h to obtain reaction mixture 2.

[0050] Step 3: Cool the reaction mixture 2 from Step 2 to room temperature and filter the resulting precipitate. Wash with methanol and dry under vacuum for 1.5 h to obtain reaction mixture 3, i.e., the nitration product.

[0051] Step 4: Suspend the reaction mixture 3 obtained in Step 3 in a mixture of ethanol and NaSH aqueous solution, heat the solution under reflux for 3 hours, and then cool the entire reaction mixture to obtain reaction mixture 4; wherein, in this embodiment, the mass concentration of the NaSH aqueous solution is 40%, and the volume to mass ratio of ethanol and NaSH in the ethanol and NaSH aqueous solution is 200 mL: 17.3 g.

[0052] Step 5: The precipitate obtained from the filtered and cooled reaction mixture 4 in Step 4 is dried under vacuum and purified by column chromatography using a gradient elution with n-hexane and ethyl acetate in a volume ratio of 1:2 to obtain a yellow solid product, namely 1,6-diaminopyrene, with a yield of 9.19 g and a yield of 32%.

[0053] The structural identification of 1,6-diaminopyrene provided in this embodiment is as follows:

[0054] GC-MS: 232.1 (m / z);

[0055] NMR measurements showed: 1H NMR (400MHz, DMSO-d6) δ 7.80 (d, 2H, Ar-H), 7.74 (d, 2H, Ar-H), 7.68 (d, 2H, Ar-H), 7.26 (d, 2H, Ar-H), 5.93 (d, 4H, Ar-NH2);

[0056] 13C NMR (100MHz, DMSO-d6) δ142.78,127.09,125.48,124.34,123.06,117.27,116.61,113.39;

[0057] Step 6: The product 1,6-diaminopyrene obtained in Step 5 is subjected to phosgenation reaction at 40°C with 100 mL of chlorobenzene as solvent and phosgene continuously introduced at 1.5 g / min, while maintaining the pressure of the reactor at 0.05 MPa. The reaction time is 3 h to obtain reactant 6.

[0058] Step 7: Slowly heat the reactant 6 obtained in Step 6 to 130°C, and continuously introduce phosgene at a rate of 1.5 g / min while maintaining the pressure of the reactor at 0.05 MPa. Continue to introduce phosgene to carry out a second-stage phosgenation reaction, so that the intermediates such as amine hydrochloride and acyl chloride can be further reacted and converted into organic isocyanates, and finally 1,6-pyrene diisocyanate is obtained with a yield of 10.6 g and a yield of 95%.

[0059] The structure of the 1,6-pyrene diisocyanate provided in this embodiment is identified as follows:

[0060] NMR measurements showed: 1H NMR (400MHz, DMSO-d6) δ 8.48 (d, 2H, Ar-H), 8.06 (d, 2H, Ar-H), 7.89 (d, 2H, Ar-H), 7.43 (d, 2H, Ar-H);

[0061] 13C NMR (100MHz, DMSO-d6) δ 135.8, 131.6, 129.1, 127.8, 126.9, 125.7, 125.2, 124.0, 122.9.

[0062] Example 2:

[0063] This embodiment provides a 1,6-pyrene diisocyanate, the preparation method of which includes the following specific steps:

[0064] Step 1: Add 50 mL of glacial acetic acid to 25 g of pyrene (123.6 mmol) and stir at 90 °C until dissolved to obtain reaction mixture 1;

[0065] Step 2: Slowly add a mixture of 19 mL nitric acid and 45 mL sulfuric acid (80% purity) to reaction mixture 1. Stir the resulting yellow suspension at 90°C for 1 hour to obtain reaction mixture 2.

[0066] Step 3: Cool the reaction mixture 2 from Step 2 to room temperature and filter the resulting precipitate. Wash with methanol and dry under vacuum for 1 hour to obtain reaction mixture 3, i.e., the nitration product.

[0067] Step 4: Suspend the reaction mixture 3 obtained in Step 3 in a mixture of ethanol and NaSH aqueous solution, heat the solution under reflux for 3 hours, and then cool the entire reaction mixture to obtain reaction mixture 4. In this embodiment, the mass concentration of the NaSH aqueous solution is 40%, and the volume to mass ratio of ethanol and NaSH in the ethanol and NaSH aqueous solution is 200 mL: 17.3 g.

[0068] Step 5: The precipitate obtained from the filtered and cooled reaction mixture 4 in Step 4 was dried under vacuum and purified by column chromatography with hexane / ethyl acetate as eluent at a volume ratio of 1:2 to obtain a yellow solid product, namely 1,6-diaminopyrene, with a yield of 9.76 g and a yield of 34%.

[0069] The structural identification of 1,6-diaminopyrene provided in this embodiment is as follows:

[0070] GC-MS: 232.1 (m / z);

[0071] NMR measurements showed: 1H NMR (400MHz, DMSO-d6) δ 7.80 (d, 2H, Ar-H), 7.74 (d, 2H, Ar-H), 7.68 (d, 2H, Ar-H), 7.26 (d, 2H, Ar-H), 5.93 (d, 4H, Ar-NH2);

[0072] 13C NMR (100MHz, DMSO-d6) δ142.78,127.09,125.48,124.34,123.06,117.27,116.61,113.39;

[0073] Step 6: The product 1,6-diaminopyrene obtained in Step 5 is subjected to phosgenation reaction at 40°C with 100 mL of chlorobenzene as solvent and phosgene continuously introduced at 1.5 g / min, while maintaining the pressure of the reactor at 0.05 MPa. The reaction time is 3 h to obtain reactant 6.

[0074] Step 7: Slowly heat reactant 6 obtained in step 6 to 130°C, continuously introduce phosgene at 1.5 g / min, maintain the pressure of the reactor at 0.05 MPa and continue to continuously introduce phosgene to carry out a second-stage phosgenation reaction, so that the intermediates such as amine hydrochloride and acyl chloride can be further reacted and converted into organic isocyanates, and finally 10.87 g of 1,6-pyrene diisocyanate is obtained, with a yield of 91%;

[0075] The structure of the 1,6-pyrene diisocyanate provided in this embodiment is identified as follows:

[0076] NMR measurements showed: 1H NMR (400MHz, DMSO-d6) δ 8.48 (d, 2H, Ar-H), 8.06 (d, 2H, Ar-H), 7.89 (d, 2H, Ar-H), 7.43 (d, 2H, Ar-H);

[0077] 13C NMR (100MHz, DMSO-d6) δ 135.8, 131.6, 129.1, 127.8, 126.9, 125.7, 125.2, 124.0, 122.9.

[0078] Example 3:

[0079] This embodiment provides a 1,6-pyrene diisocyanate, the preparation method of which includes the following specific steps:

[0080] Step 1: Add 50 mL of glacial acetic acid to 25 g of pyrene (123.6 mmol) and stir at 90 °C until dissolved to obtain reaction mixture 1;

[0081] Step 2: Slowly add the mixture of 18.3g magnesium nitrate and 50mL glacial acetic acid to reaction mixture 1. Stir the resulting yellow suspension at 90℃ for 1h to obtain reaction mixture 2.

[0082] Step 3: Cool the reaction mixture 2 from Step 2 to room temperature and filter the resulting precipitate. Wash with methanol and dry under vacuum for 2 hours to obtain reaction mixture 3, i.e., the nitration product.

[0083] Step 4: Suspend the reaction mixture 3 obtained in Step 3 in a mixture of ethanol and NaSH aqueous solution, heat the solution under reflux for 3 hours, and then cool the entire reaction mixture to obtain reaction mixture 4; wherein, in this embodiment, the mass concentration of the NaSH aqueous solution is 40%, and the volume to mass ratio of ethanol and NaSH in the ethanol and NaSH aqueous solution is 200 mL: 17.3 g.

[0084] Step 5: The filtered and cooled reaction mixture 4 from Step 4 was dried under vacuum and purified by column chromatography using a gradient elution with n-hexane and ethyl acetate in a volume ratio of 1:2 to obtain a yellow solid product, namely 1,6-diaminopyrene, with a yield of 9.47 g and a yield of 33%.

[0085] The structural identification of 1,6-diaminopyrene provided in this embodiment is as follows:

[0086] GC-MS: 232.1 (m / z);

[0087] NMR measurements showed: 1H NMR (400MHz, DMSO-d6) δ 7.80 (d, 2H, Ar-H), 7.74 (d, 2H, Ar-H), 7.68 (d, 2H, Ar-H), 7.26 (d, 2H, Ar-H), 5.93 (d, 4H, Ar-NH2);

[0088] 13C NMR (100MHz, DMSO-d6) δ142.78,127.09,125.48,124.34,123.06,117.27,116.61,113.39;

[0089] Step 6: The product 1,6-diaminopyrene obtained in Step 5 was subjected to phosgenation at 40°C with 100 mL of chlorobenzene as solvent and phosgene continuously introduced at 1.5 g / min, while maintaining the pressure of the reactor at 0.05 MPa for 3 h, to obtain reactant 6.

[0090] Step 7: Slowly heat the reactant 6 obtained in Step 6 to 130℃ and continuously introduce phosgene at 1.5g / min, maintaining the pressure of the reactor at 0.05MPa, so that the intermediates such as amine hydrochloride and acyl chloride can be further reacted and converted into organic isocyanates, and finally 1,6-pyrene diisocyanate is obtained with a yield of 11.0g and a yield of 97%.

[0091] The structure of the 1,6-pyrene diisocyanate provided in this embodiment is identified as follows:

[0092] NMR measurements showed: 1H NMR (400MHz, DMSO-d6) δ 8.48 (d, 2H, Ar-H), 8.06 (d, 2H, Ar-H), 7.89 (d, 2H, Ar-H), 7.43 (d, 2H, Ar-H);

[0093] 13C NMR (100MHz, DMSO-d6) δ 135.8, 131.6, 129.1, 127.8, 126.9, 125.7, 125.2, 124.0, 122.9.

[0094] Example 4:

[0095] This embodiment provides a 1,6-pyrene diisocyanate, the preparation method of which includes the following specific steps:

[0096] Step 1: Add 50 mL of glacial acetic acid to 25 g of pyrene (123.6 mmol) and stir at 90 °C until dissolved to obtain reaction mixture 1;

[0097] Step 2: Slowly add the mixture of 19 mL nitric acid and 50 mL glacial acetic acid to reaction mixture 1. Stir the resulting yellow suspension at 90 °C for 1 h to obtain reaction mixture 2.

[0098] Step 3: Cool the reaction mixture 2 from Step 2 to room temperature and filter the resulting precipitate. Wash with methanol and dry under vacuum for 2 hours to obtain reaction mixture 3, i.e., the nitration product.

[0099] Step 4: Add the nitration product obtained in Step 3 to 40 mL of distilled water, add 50 mL of sulfuric acid with a mass percentage of 15%, purge with nitrogen, add 10% palladium on carbon catalyst, pass hydrogen gas at a flow rate of 60 mL / min, heat to 80 °C, and obtain a precipitate.

[0100] Step 5: The precipitate obtained by filtration was dried under vacuum and purified by column chromatography with hexane / ethyl acetate as eluent at a volume ratio of 1:2 to obtain a yellow solid product, namely 1,6-diaminopyrene, with a yield of 10.0 g and a yield of 35%.

[0101] The structural identification of 1,6-diaminopyrene provided in this embodiment is as follows:

[0102] GC-MS: 232.1 (m / z);

[0103] NMR measurements showed: 1H NMR (400MHz, DMSO-d6) δ 7.80 (d, 2H, Ar-H), 7.74 (d, 2H, Ar-H), 7.68 (d, 2H, Ar-H), 7.26 (d, 2H, Ar-H), 5.93 (d, 4H, Ar-NH2);

[0104] 13C NMR (100MHz, DMSO-d6) δ142.78,127.09,125.48,124.34,123.06,117.27,116.61,113.39;

[0105] Step 6: The product 1,6-diaminopyrene obtained in Step 5 was subjected to phosgenation at 40°C with 100 mL of chlorobenzene as solvent and phosgene continuously introduced at 1.5 g / min, while maintaining the pressure of the reactor at 0.05 MPa for 3 h, to obtain reactant 6.

[0106] Step 7: Slowly heat the reactant 6 obtained in Step 6 to 130°C, and continuously introduce phosgene at a rate of 1.5 g / min while maintaining the pressure of the reactor at 0.05 MPa. Continue to introduce phosgene to carry out a second-stage phosgenation reaction, so that the intermediates such as amine hydrochloride and acyl chloride can be further reacted and converted into organic isocyanates, and finally 1,6-pyrene diisocyanate is obtained with a yield of 10.94 g and a yield of 89%.

[0107] The structure of the 1,6-pyrene diisocyanate provided in this embodiment is identified as follows:

[0108] NMR measurements showed: 1H NMR (400MHz, DMSO-d6) δ 8.48 (d, 2H, Ar-H), 8.06 (d, 2H, Ar-H), 7.89 (d, 2H, Ar-H), 7.43 (d, 2H, Ar-H);

[0109] 13C NMR (100MHz, DMSO-d6) δ 135.8, 131.6, 129.1, 127.8, 126.9, 125.7, 125.2, 124.0, 122.9.

[0110] Example 5:

[0111] This embodiment provides a 1,6-pyrene diisocyanate, the preparation method of which includes the following specific steps:

[0112] Step 1: Add 50 mL of glacial acetic acid to 25 g of pyrene (123.6 mmol) and stir at 90 °C until dissolved to obtain reaction mixture 1;

[0113] Step 2: Slowly add the mixture of 19 mL nitric acid and 50 mL glacial acetic acid to reaction mixture 1. Stir the resulting yellow suspension at 90 °C for 1 h to obtain reaction mixture 2.

[0114] Step 3: Cool the reaction mixture 2 from Step 2 to room temperature and filter the resulting precipitate. Wash with methanol and dry under vacuum for 1 hour to obtain reaction mixture 3, i.e., the nitration product.

[0115] Step 4: Add 7g of iron powder to the reaction mixture 3 obtained in Step 3, adjust the pH to 5 with 12% ammonium chloride and water, heat to 40℃ and stir evenly, then heat to 95℃ and react for 1.5h to obtain reaction mixture 4;

[0116] Step 5: The precipitate obtained by filtering the reaction mixture 4 obtained in Step 4 is dried under vacuum and purified by column separation using gradient elution with n-hexane and ethyl acetate in a volume ratio of 1:2 to obtain a yellow solid product, namely 1,6-diaminopyrene, with a yield of 9.8 g and a yield of 34%.

[0117] The structural identification of 1,6-diaminopyrene provided in this embodiment is as follows:

[0118] GC-MS: 232.1 (m / z);

[0119] NMR measurements showed: 1H NMR (400MHz, DMSO-d6) δ 7.80 (d, 2H, Ar-H), 7.74 (d, 2H, Ar-H), 7.68 (d, 2H, Ar-H), 7.26 (d, 2H, Ar-H), 5.93 (d, 4H, Ar-NH2);

[0120] 13C NMR (100MHz, DMSO-d6) δ142.78,127.09,125.48,124.34,123.06,117.27,116.61,113.39;

[0121] Step 6: The product 1,6-diaminopyrene obtained in Step 5 is subjected to phosgenation reaction at 40°C with 100 mL of chlorobenzene as solvent and phosgene continuously introduced at 1.5 g / min, maintaining the pressure of the reactor at 0.05 MPa for 2 h, to obtain reactant 6.

[0122] Step 7: Slowly heat the reactant 6 obtained in Step 6 to 130°C, and continuously introduce phosgene at a rate of 1.5 g / min while maintaining the pressure of the reactor at 0.05 MPa. Continue to introduce phosgene to carry out a second-stage phosgenation reaction, so that the intermediates such as amine hydrochloride and acyl chloride can be further reacted and converted into organic isocyanates, and finally 1,6-pyrene diisocyanate is obtained with a yield of 11.1 g and a yield of 93%.

[0123] The structure of the 1,6-pyrene diisocyanate provided in this embodiment is identified as follows:

[0124] NMR measurements showed: 1H NMR (400MHz, DMSO-d6) δ 8.48 (d, 2H, Ar-H), 8.06 (d, 2H, Ar-H), 7.89 (d, 2H, Ar-H), 7.43 (d, 2H, Ar-H);

[0125] 13C NMR (100MHz, DMSO-d6) δ 135.8, 131.6, 129.1, 127.8, 126.9, 125.7, 125.2, 124.0, 122.9.

[0126] Example 6:

[0127] This embodiment provides a 1,6-pyrene diisocyanate, the preparation method of which includes the following specific steps:

[0128] Step 1: Add 50 mL of glacial acetic acid to 25 g of pyrene (123.6 mmol) and stir at 90 °C until dissolved to obtain reaction mixture 1;

[0129] Step 2: Slowly add the mixture of 19 mL nitric acid and 50 mL glacial acetic acid to reaction mixture 1. Stir the resulting yellow suspension at 90 °C for 1 h to obtain reaction mixture 2.

[0130] Step 3: Cool the reaction mixture 2 from Step 2 to room temperature and filter the resulting precipitate. Wash with methanol and dry under vacuum for 2 hours to obtain reaction mixture 3, i.e., the nitration product.

[0131] Step 4: Suspend the reaction mixture 3 obtained in Step 3 in a mixture of ethanol and NaSH aqueous solution, heat the solution under reflux for 3 hours, and then cool the entire reaction mixture to obtain reaction mixture 4; wherein, in this embodiment, the mass concentration of the NaSH aqueous solution is 40%, and the volume to mass ratio of ethanol and NaSH in the ethanol and NaSH aqueous solution is 200 mL: 17.3 g.

[0132] Step 5: The precipitate obtained by filtering and cooling the reaction mixture 4 in Step 4 is dried under vacuum and purified by column separation using hexane and ethyl acetate in a volume ratio of 1:2 to obtain a yellow solid product, namely 1,6-diaminopyrene, with a yield of 8.6 g and a yield of 30%.

[0133] The structural identification of 1,6-diaminopyrene provided in this embodiment is as follows:

[0134] GC-MS: 232.1 (m / z). NMR determination: 1H NMR (400MHz, DMSO-d6) δ 7.80 (d, 2H, Ar-H), 7.74 (d, 2H, Ar-H), 7.68 (d, 2H, Ar-H), 7.26 (d, 2H, Ar-H), 5.93 (d, 4H, Ar-NH2);

[0135] 13C NMR (100MHz, DMSO-d6) δ142.78,127.09,125.48,124.34,123.06,117.27,116.61,113.39;

[0136] Step 6: Dissolve the product 1,6-diaminopyrene obtained in Step 5 in 45 mL of 1,2-dichloroethane, and add it dropwise to 55 g of triphosgene tetrahydrofuran solution, wherein the mass concentration of triphosgene tetrahydrofuran solution is 20%. After heating and reflux reaction, 1,6-pyrene diisocyanate is finally obtained with a yield of 9.7 g and a yield of 92%.

[0137] The structure of the 1,6-pyrene diisocyanate provided in this embodiment is identified as follows:

[0138] NMR measurements showed: 1H NMR (400MHz, DMSO-d6) δ 8.48 (d, 2H, Ar-H), 8.06 (d, 2H, Ar-H), 7.89 (d, 2H, Ar-H), 7.43 (d, 2H, Ar-H);

[0139] 13C NMR (100MHz, DMSO-d6) δ 135.8, 131.6, 129.1, 127.8, 126.9, 125.7, 125.2, 124.0, 122.9.

[0140] This invention provides a method for preparing polyurethane using 1,6-pyrene diisocyanate and 1,5-naphthalene diisocyanate (hereinafter referred to as "NDI") as described in Examples 1 to 6 via a one-step foaming method. This invention also provides a method for preparing polyurethane using 1,6-pyrene diisocyanate and diphenylmethane diisocyanate (hereinafter referred to as "MDI") as described in Examples 1 to 6 via a prepolymerization method.

[0141] Method 1: One-step foaming method for preparing polyurethane

[0142] Application Example 1:

[0143] A method for preparing polyurethane using a one-step foaming process includes the following steps:

[0144] The polyurethane foam composition was added to a mold and quickly stirred to mix evenly at a speed of 3000 r / min for 20 s. The mixture was then foamed, cured, and aged at a temperature of 90 ℃ for 24 h to obtain polyurethane foam.

[0145] Here, the polyurethane foaming composition comprises 100 parts of 1,6-hexanediol. In Example 1, the molar ratio of 1,6-pyrene diisocyanate to 1,6-hexanediol is 1.2:1. The foaming agent is 3.5 parts of deionized water, the chain extender is 0.9 parts of 1,4-butanediol, and the catalyst is 1.1 parts of triethylenediamine. The isocyanate group (hereinafter referred to as "NCO") content in the 1,6-pyrene diisocyanate is 28.4%.

[0146] Application Example 2:

[0147] The difference from Application 1 is that in this application example, "Preparation of 1,6-pyrene diisocyanate in Example 1" is replaced with "NDI," while the remaining steps and conditions are the same. The NCO content of the NDI used in this application example is 40.0%.

[0148] Method 2: Preparation of polyurethane via prepolymer method

[0149] Application Example 3:

[0150] A method for preparing polyurethane using a prepolymer method includes the following steps:

[0151] (1) Excess diisocyanate reacts with polypropylene glycol at 95°C to generate a prepolymer with NCO terminal groups, the NCO content being 12%; In this application example, the diisocyanate used is 1,6-pyrene diisocyanate prepared in Example 1 of this invention, the NCO content of which is 28.4%.

[0152] (2) Casting: The prepolymer and chain extender components are mixed at a mass ratio of 100:10.5, the mixing speed is 1500 r / min, and the mixture is stirred for 30 s. The reaction liquid is then poured into a mold at a temperature of 95℃, pre-cured, and then demolded. The chain extender components include the following components in parts by weight: 45 parts of chain extender 1,6-hexanediol, 36 parts of catalyst tetramethylethylenediamine, 14 parts of foaming agent HFC-365mfc, and surfactant eucalyptus. FLOW 499U 5 parts; of which, the foaming agent HFC-365mfc was purchased from Shandong Aolilong Chemical Co., Ltd., and the surfactant Ucarbamate was purchased from Shandong Aolilong Chemical Co., Ltd. FLOW was purchased from UCAR Chemicals (Shanghai) Co., Ltd.

[0153] (3) Post-curing: After demolding, the product is cured in an oven at 105℃ for 16 hours and left at room temperature for 5 days to obtain polyurethane.

[0154] Application Example 4:

[0155] The difference between this application example and Example 3 is that "Preparation of 1,6-pyrene diisocyanate in Example 1" is replaced with "MDI", while the remaining steps and conditions are the same. The NCO content of the MDI used in this application example is 32.0%.

[0156] The polyurethanes prepared by one-step foaming process using 1,6-pyrene diisocyanate in Application Example 1 and NDI in Application Example 2 were tested and their properties are shown in Table 1.

[0157] Table 1. Performance test results of polyurethane prepared by one-step foaming method

[0158]

[0159]

[0160] The polyurethane prepared by prepolymerization of 1,6-pyrene diisocyanate and MDI is shown in Table 2 after testing.

[0161] Table 2 Performance test results of polyurethane prepared by the prepolymer method

[0162]

[0163] Table 1 shows that the polyurethane prepared by the one-step foaming method using 1,6-pyrene diisocyanate exhibits the following properties after testing: The microporous polyurethane elastomer has a small constant compression set, indicating good elastic recovery performance. Simultaneously, it has a large loss factor, indicating rapid energy loss under the same conditions and good shock absorption performance. Table 2 shows that the polyurethane prepared by the prepolymerization method using 1,6-pyrene diisocyanate has high tensile strength and tear strength. Its tensile property change ratio after immersion at 70℃ for one week is close to 1, showing good stability and minimal change, indicating that the polyurethane prepared by the prepolymerization method using 1,6-pyrene diisocyanate has high resistance to various media.

[0164] The above data demonstrate that the polyurethane products prepared by the method of this invention have good application prospects as high-strength damping components and corrosion-resistant components that withstand dynamic fatigue.

[0165] The above description of the embodiments is merely for the convenience of those skilled in the art to understand and use. Those skilled in the art can select appropriate production processes according to product needs. Of course, the above descriptions are only some embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing 1,6-pyrene diisocyanate, characterized in that, Includes the following steps: Step 1: Add glacial acetic acid to pyrene and stir evenly at 80-100℃ to obtain reaction mixture 1; Step 2: Slowly add the nitrifying agent to reaction mixture 1 from step 1. Stir the resulting yellow suspension at 80-100°C for 0.5-2 h to obtain reaction mixture 2. The nitrifying agent in step 2 is a mixture of nitric acid and glacial acetic acid. The volume ratio of nitric acid to glacial acetic acid is 1:2 to 1:

5. Step 3: Cool the reaction mixture 2 from Step 2 to room temperature and filter the resulting precipitate. Wash with methanol and dry under vacuum to obtain reaction mixture 3, i.e., the nitration product. Step 4: The reaction mixture 3 obtained in Step 3 is subjected to a reduction reaction to obtain reaction mixture 4; the reduction is sulfide reduction, hydrogenation reduction or iron powder reduction; Step 5: The precipitate obtained from the filtered and cooled reaction mixture 4 in Step 4 is dried under vacuum and purified by column separation using gradient elution with n-hexane and ethyl acetate in a volume ratio of 1:1 to 1:3 to obtain reactant 5, namely the yellow solid product 1,6-diaminopyrene. Step 6: The 1,6-diaminopyrene obtained in Step 5 is subjected to phosgenation reaction at 30-60°C with chlorobenzene as solvent and phosgene continuously introduced for 2-6 hours to obtain reactant 6. Step 7: Slowly heat the reactant 6 obtained in Step 6 to 100-150°C and continuously introduce phosgene to carry out a two-stage phosgenation reaction, so that the amine hydrochloride and acyl chloride intermediates can be further reacted and converted into organic isocyanates, thus obtaining 1,6-pyrene diisocyanate.

2. The method for preparing 1,6-pyrene diisocyanate according to claim 1, characterized in that, In step one, the mass-to-volume ratio of pyrene to glacial acetic acid is 1:1 to 1:20.

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