Preparation method of high temperature resistant modified polyurethane elastomer

Abstract

The invention belongs to the technical field of polyurethane elastomers, and discloses a preparation method of a high temperature resistant modified polyurethane elastomer. The present invention uses polytetrahydrofuran ether glycol, 4,4'-methylenebis(phenyl isocyanate), 1,4-butanediol, etc. as raw materials, and carbamate-based polyaryletherketone as a modifier, and the reaction obtains a high temperature resistant modified polyurethane elastomer. Polyaryletherketone contains the same carbamate structural unit as the polyurethane elastomer, and the two have good compatibility, and the phenomenon of phase separation will not occur, which can play a reinforcing role, improve the tensile strength of the polyurethane elastomer, the mechanical properties such as tear strength. At the same time, polyaryletherketone contains dendritic hyperbranched network molecular chains, forms a spatial crosslinking effect with polyurethane molecular chains, hinders the chain motion of polyurethane, is conducive to increasing the thermal decomposition temperature, and enhances the high temperature resistance of elastomeric materials.

Description

Technical Field

[0001] The invention belongs to the technical field of polyurethane elastomers, and specifically relates to a method for preparing a high-temperature resistant modified polyurethane elastomer. Background Art

[0002] The physical crosslinking formed by hydrogen bonds in the molecular chain of polyurethane elastomer can play a good reinforcing role, making polyurethane elastomer have good physical and chemical properties, and is widely used in medical devices, shoemaking industry, construction materials and other fields. Improving the mechanical and high temperature resistance properties of polyurethane elastomer materials is a research hotspot. At present, inorganic fillers, high-performance resins and other materials are mainly used to fill and modify polyurethane to improve its performance.

[0003] As a high-performance resin material, polyetherketone polymers have excellent mechanical strength, high temperature resistance, chemical resistance and other properties, and are used in epoxy resins, phenolic resins, polyurethanes and other materials. However, the compatibility between polyaryletherketone and polyurethane is poor, and groups such as hydroxyl groups are usually introduced into polyetherketone to participate in the polymerization reaction of polyurethane to improve the interface performance between the two. However, the reaction process of this method is relatively complicated and the cost is relatively high. For example, the patent with the authorization announcement number CN109293874B discloses a polyetheretherketone modified polyurethane water-based resin and a preparation method, using amine-modified polyetheretherketone, oligomer polyol, diisocyanate, etc. as raw materials to obtain polyetheretherketone modified polyurethane water-based resin. However, the preparation method of the amine-modified polyetheretherketone of the patent is relatively complicated, and it is necessary to react with isocyanate to give good performance to polyurethane. Summary of the invention

[0004] Technical problems solved: A preparation method of a high-temperature resistant modified polyurethane elastomer is provided, which solves the problem of poor high-temperature resistance and other properties of the polyurethane elastomer.

[0005] Technical solution: Preparation method of high temperature resistant modified polyurethane elastomer:

[0006] Step S1: Add sulfolane, toluene, tetrafluoromonomer in a mass ratio of (23-46): (158-180): 100: (220-260), 4,4'-difluorobenzophenone, hydroquinone and potassium carbonate into a reaction bottle equipped with a water separator and a reflux tube, reflux with water treatment, and then stir to react. After cooling, add the solution into water, filter, wash with water and ethanol, and dry to obtain carbamate-based polyaryletherketone.

[0007] The structural formula of tetrafluoroethylene monomer is as follows:

[0008] ;

[0009] Step S2: Add dried and dehydrated polyol and 4,4'-methylenebis(phenyl isocyanate) into a reaction bottle, stir and react at 75-85°C for 1.5-2.5h, then add a chain extender and carbamate-based polyaryletherketone, stir until a gel state is formed, add the product to a mold preheated to 110°C, place it for 2h, then demold it, place it in a heating box, mature it at 115-130°C for 24-36h, cool it, and obtain a high temperature resistant modified polyurethane elastomer.

[0010] Preferably, in step S1, the temperature during reflux with water is 145-155° C., and the time is 3-4 h; the temperature during reaction is 200-210° C., and the time is 6-10 h.

[0011] Preferably, in step S2, the mass ratio of the polyol, 4,4'-methylenebis(phenyl isocyanate), chain extender, and carbamate-based polyaryletherketone is 100:(30-33):(9-12):(5-20).

[0012] Preferably, the polyol is polytetramethylene glycol or polybutylene adipate glycol or polycaprolactone glycol; and the chain extender is 1,4-butanediol or 1,6-hexanediol.

[0013] Preferably, the preparation method of the tetrafluoromonomer is as follows: add toluene or ethyl acetate or 1,4-dioxane solvent, a mass ratio of 100: (106-118) of 4,4'-methylenebis(phenyl isocyanate) and 3,5-difluorophenol to a reaction bottle, heat to 75-90°C, react for 4-6h, distill the solution under reduced pressure, separate by silica gel column chromatography, and elute with a solution of ethyl acetate and petroleum ether to obtain a tetrafluoromonomer.

[0014] Beneficial effects: The present invention reacts 4,4'-methylenebis(phenyl isocyanate) and 3,5-difluorophenol to obtain a tetrafluoromonomer, which is then polycondensed with 4,4'-difluorobenzophenone and hydroquinone to obtain a carbamate-based polyaryletherketone containing a dendritic hyperbranched network molecular chain.

[0015] The present invention uses polytetrahydrofuran ether glycol, 4,4'-methylenebis(phenyl isocyanate), 1,4-butanediol and the like as raw materials and carbamate-based polyaryletherketone as a modifier to obtain a high temperature resistant modified polyurethane elastomer. The polyaryletherketone has strong mechanical strength and high temperature resistance, and contains the same carbamate structural unit as the polyurethane elastomer. The two have good compatibility and will not undergo phase separation, which can enhance the tensile strength, tear strength and other mechanical properties of the polyurethane elastomer. At the same time, the polyaryletherketone contains dendritic hyperbranched network molecular chains, which form a spatial cross-linking effect with the polyurethane molecular chain, hinder the chain movement of the polyurethane, are conducive to increasing the thermal decomposition temperature, and enhance the high temperature resistance of the elastomer material. DETAILED DESCRIPTION

[0016] For ease of understanding of the present invention, the present invention will be described in more detail below. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments or examples described herein. On the contrary, the purpose of providing these embodiments or examples is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0017] Example 1: Preparation method of high temperature resistant modified polyurethane elastomer:

[0018] (1) Add 60 mL of ethyl acetate, 5 g of 4,4'-methylenebis(phenyl isocyanate), and 5.3 g of 3,5-difluorophenol to a reaction flask, heat to 90°C, react for 4 hours, distill the solution under reduced pressure, separate by silica gel column chromatography, and elute with a solution of ethyl acetate and petroleum ether to obtain tetrafluoromonomer. The reaction formula is as follows:

[0019] ;

[0020] (2) Add 40 mL of sulfolane, 20 mL of toluene, 0.7 g of tetrafluoromonomer, 3.4 g of 4,4'-difluorobenzophenone, 2 g of hydroquinone, and 5.2 g of potassium carbonate to a reaction bottle equipped with a water separator and a reflux tube, heat to 145°C, reflux with water for 4 hours, then heat to 210°C, stir and react for 8 hours, cool and add the solution to water, filter, wash with water and ethanol, and dry to obtain carbamate-based polyaryletherketone. The reaction formula is as follows:

[0021] ;

[0022] (3) Add 40 g of dried and dehydrated polytetramethylene ether glycol 2000 and 12.6 g of 4,4'-methylenebis(phenyl isocyanate) into a reaction bottle, stir and react at 85°C for 1.5 h, then add 3.6 g of chain extender 1,4-butanediol and 2 g of carbamate-based polyaryletherketone, stir until a gel state is formed, add the product into a mold preheated to 110°C, leave it for 2 h, then demould it, place it in a heating box, mature it at 115°C for 36 h, and cool it to obtain a high temperature resistant modified polyurethane elastomer.

[0023] Example 2: Preparation method of high temperature resistant modified polyurethane elastomer:

[0024] (1) Add 80 mL of 1,4-dioxane solvent, 5 g of 4,4'-methylenebis(phenyl isocyanate), and 5.9 g of 3,5-difluorophenol to a reaction bottle, heat to 75°C, react for 5 hours, distill the solution under reduced pressure, separate by silica gel column chromatography, and elute with a solution of ethyl acetate and petroleum ether to obtain a tetrafluoromonomer;

[0025] (2) Add 30 mL of sulfolane, 15 mL of toluene, 0.46 g of tetrafluoromonomer, 3.6 g of 4,4'-difluorobenzophenone, 2 g of hydroquinone, and 4.4 g of potassium carbonate to a reaction bottle equipped with a water separator and a reflux tube, heat to 155°C, reflux with water for 3 h, then heat to 210°C, stir and react for 6 h, cool and add the solution to water, filter, wash with water and ethanol, and dry to obtain a carbamate-based polyaryletherketone;

[0026] (3) Add 40 g of dried and dehydrated polycaprolactone diol 2000 and 13.2 g of 4,4'-methylenebis(phenyl isocyanate) into a reaction bottle, stir and react at 75°C for 2.5 h, then add 4.8 g of 1,6-hexanediol and 6 g of carbamate-based polyaryletherketone, stir until a gel state is formed, add the product into a mold preheated to 110°C, leave it for 2 h, then demold, place it in a heating box, mature it at 130°C for 24 h, and cool it to obtain a high temperature resistant modified polyurethane elastomer.

[0027] Example 3: Preparation method of high temperature resistant modified polyurethane elastomer:

[0028] (1) Add 80 mL of toluene solvent, 5 g of 4,4'-methylenebis(phenyl isocyanate), and 5.6 g of 3,5-difluorophenol to a reaction bottle, heat to 75°C, react for 6 hours, distill the solution under reduced pressure, separate by silica gel column chromatography, and elute with a solution of ethyl acetate and petroleum ether to obtain a tetrafluoromonomer;

[0029] (2) Add 40 mL of sulfolane, 20 mL of toluene, 0.92 g of tetrafluoromonomer, 3.16 g of 4,4'-difluorobenzophenone, 2 g of hydroquinone, and 4.8 g of potassium carbonate to a reaction bottle equipped with a water separator and a reflux tube, heat to 155°C, reflux with water for 3 h, then heat to 200°C, stir and react for 10 h, cool and add the solution to water, filter, wash with water and ethanol, and dry to obtain a carbamate-based polyaryletherketone;

[0030] (3) Add 40 g of dried and dehydrated polybutylene adipate diol 2000 and 12 g of 4,4'-methylenebis(phenyl isocyanate) into a reaction bottle, stir and react at 85°C for 2 h, then add 3.6 g of chain extender 1,4-butanediol and 8 g of carbamate-based polyaryletherketone, stir until a gel state is formed, add the product into a mold preheated to 110°C, leave it for 2 h, then demould it, place it in a heating box, mature it at 120°C for 24 h, and cool it to obtain a high temperature resistant modified polyurethane elastomer.

[0031] Comparative Example 1: The difference between this comparative example and Example 1 is that no carbamate-based polyaryletherketone is added to the polyurethane elastomer.

[0032] (1) Add 40 g of dried and dehydrated polytetramethylene ether glycol 2000 and 12.6 g of 4,4'-methylenebis(phenyl isocyanate) into a reaction bottle, stir and react at 85°C for 1.5 h, then add 3.6 g of chain extender 1,4-butanediol, stir until a gel state is formed, add the product into a mold preheated to 110°C, place it for 2 h, then demould it, place it in a heating box, mature it at 115°C for 36 h, and cool it to obtain a high temperature resistant modified polyurethane elastomer.

[0033] Comparative Example 2: The difference between this comparative example and Example 1 is that no tetrafluoro monomer is added during the preparation of polyaryletherketone.

[0034] (1) Add 40 mL of sulfolane, 20 mL of toluene, 3.4 g of 4,4'-difluorobenzophenone, 2 g of hydroquinone, and 5.2 g of potassium carbonate to a reaction bottle equipped with a water separator and a reflux tube, heat to 145°C, reflux with water for 4 hours, then heat to 210°C, stir and react for 8 hours, cool and add the solution to water, filter, wash with water and ethanol, and dry to obtain polyaryletherketone;

[0035] (2) Add 40 g of dried and dehydrated polytetramethylene ether glycol 2000 and 12.6 g of 4,4'-methylenebis(phenyl isocyanate) into a reaction bottle, stir and react at 85°C for 1.5 h, then add 3.6 g of chain extender 1,4-butanediol and 2 g of polyaryletherketone, stir until a gel state is formed, add the product into a mold preheated to 110°C, let it stand for 2 h, then demold, place it in a heating box, mature it at 115°C for 36 h, and cool it to obtain a high temperature resistant modified polyurethane elastomer.

[0036] Comparative Example 3: The main difference between this comparative example and Example 1 is that 4-fluorophenol is used instead of 3,5-difluorophenol when preparing the fluorine monomer.

[0037] (1) Add 60 mL of ethyl acetate, 5 g of 4,4'-methylenebis(phenyl isocyanate), and 4.5 g of 4-fluorophenol to a reaction flask, heat to 85°C, react for 3 hours, distill the solution under reduced pressure, separate by silica gel column chromatography, and elute with a solution of ethyl acetate and petroleum ether to obtain a fluorine monomer. The structural formula is ;

[0038] (2) Add 40 mL of sulfolane, 20 mL of toluene, 0.7 g of fluorine monomer, 3.4 g of 4,4'-difluorobenzophenone, 2 g of hydroquinone, and 5.2 g of potassium carbonate to a reaction bottle equipped with a water separator and a reflux tube, heat to 145°C, reflux with water for 4 hours, then heat to 210°C, stir and react for 8 hours, cool and add the solution to water, filter, wash with water and ethanol, and dry to obtain carbamate polyaryletherketone;

[0039] (3) Add 40 g of dried and dehydrated polytetramethylene ether glycol 2000 and 12.6 g of 4,4'-methylenebis(phenyl isocyanate) into a reaction bottle, stir and react at 85°C for 1.5 h, then add 3.6 g of chain extender 1,4-butanediol and 2 g of carbamate-based polyaryletherketone, stir until a gel state is formed, add the product into a mold preheated to 110°C, leave it for 2 h, then demould it, place it in a heating box, mature it at 115°C for 36 h, and cool it to obtain a high temperature resistant modified polyurethane elastomer.

[0040] The cured polyurethane elastomer was placed at room temperature for 7 days. The tensile properties were tested according to GB / T 528-2009. The tear strength was tested according to GB / T 529-2008. The test results are shown in the following table.

[0041] Table 1: Test results of various embodiments and comparative examples

[0042]

[0043] The polyurethane elastomer was placed in a thermogravimetric analyzer and subjected to a thermogravimetric performance test in a nitrogen atmosphere at a heating rate of 10°C / min from room temperature to 700°C. The test results are shown in the following table.

[0044] Table 2: Test results of various embodiments and comparative examples

[0045]

[0046] T 5% is the temperature at which the mass loss is 5%. max is the temperature at which the rate of thermal weight loss is maximum.

[0047] As can be seen from the above table, compared with Comparative Example 1, carbamate-based polyaryletherketone is added to the polyurethane elastomer in Examples 1 to 3. Polyaryletherketone itself has strong mechanical strength and high temperature resistance, and contains the same carbamate structural unit as the polyurethane elastomer. The two have good compatibility and will not undergo phase separation, which can enhance the tensile strength, tear strength and other mechanical properties of the polyurethane elastomer. The prepared polyaryletherketone contains dendritic hyperbranched network molecular chains, which form a spatial cross-linking effect with the polyurethane molecular chain, hinder the chain movement of the polyurethane, and are conducive to increasing the thermal decomposition temperature and enhancing the high temperature resistance.

[0048] Comparative Example 2: When preparing polyaryletherketone, tetrafluoromonomer containing carbamate group is not added, resulting in the polyaryletherketone obtained not containing carbamate structural unit, poor compatibility with polyurethane elastomer, and the two are prone to form phase separation defects, and the reinforcing effect of polyaryletherketone is poor. The mechanical strength and thermal decomposition temperature of the obtained polyurethane elastomer are lower than those of Example 1, and the mechanical properties and high temperature resistance are not good.

[0049] The fluorine monomer of Comparative Example 3 contains two fluorine atoms, and undergoes polycondensation reaction with 4,4'-difluorobenzophenone and hydroquinone. The obtained polyaryletherketone has a linear structure and does not contain a dendritic hyperbranched network molecular chain. The reinforcing effect on the polyaryletherketone is poor, and the mechanical strength and thermal decomposition temperature of the obtained polyurethane elastomer are lower than those of Example 1.

[0050] The above are only preferred specific implementations of the present invention; however, the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, shall make equivalent replacements or changes according to the technical solutions and improved concepts of the present invention, which shall be covered within the protection scope of the present invention.

Claims

1. A method for preparing a high temperature resistant modified polyurethane elastomer, characterized in that: The preparation method is: Step S1: adding sulfolane, toluene, tetrafluoromonomer, 4,4'-difluorobenzophenone, hydroquinone and potassium carbonate to a reaction bottle equipped with a water separator and a reflux tube, reflux with water, and then stir to react, add the solution into water after cooling, filter, wash with water and ethanol, and dry to obtain carbamate polyaryletherketone; The structural formula of the tetrafluoromonomer is as follows: ; Step S2: adding dried and dehydrated polyol and 4,4'-methylenebis(phenyl isocyanate) to a reaction bottle, stirring and reacting at 75-85°C for 1.5-2.5h, then adding a chain extender and a carbamate-based polyaryletherketone, stirring until a gel state is formed, adding the product to a preheated mold, demolding after standing, placing in a heating box, maturing at 115-130°C for 24-36h, cooling, and obtaining a high temperature resistant modified polyurethane elastomer; In the step S1, the mass ratio of tetrafluoromonomer, 4,4'-difluorobenzophenone, hydroquinone and potassium carbonate is (23-46): (158-180): 100: (220-260).

2. The method for preparing a high temperature resistant modified polyurethane elastomer according to claim 1, characterized in that: In the step S1, the temperature during reflux with water is 145-155° C., and the time is 3-4 hours; the temperature during reaction is 200-210° C., and the time is 6-10 hours.

3. The method for preparing a high temperature resistant modified polyurethane elastomer according to claim 1, characterized in that: In the step S2, the mass ratio of the polyol, 4,4'-methylenebis(phenyl isocyanate), chain extender, and carbamate-based polyaryletherketone is 100:(30-33):(9-12):(5-20).

4. The method for preparing a high temperature resistant modified polyurethane elastomer according to claim 1, characterized in that: The polyol is polytetramethylene glycol or polybutylene adipate glycol or polycaprolactone glycol; the chain extender is 1,4-butanediol or 1,6-hexanediol.

5. The method for preparing a high temperature resistant modified polyurethane elastomer according to claim 1, characterized in that: The preparation method of the tetrafluoromonomer is as follows: adding a solvent, 4,4'-methylenebis(phenyl isocyanate) and 3,5-difluorophenol into a reaction bottle, heating to 75-90°C, reacting for 4-6 hours, distilling the solution under reduced pressure, separating by silica gel column chromatography, and eluting with a solution of ethyl acetate and petroleum ether to obtain the tetrafluoromonomer.

6. The method for preparing a high temperature resistant modified polyurethane elastomer according to claim 5, characterized in that: The solvent is toluene, ethyl acetate or 1,4-dioxane.

7. The method for preparing a high temperature resistant modified polyurethane elastomer according to claim 5, characterized in that: The mass ratio of the 4,4'-methylenebis(phenyl isocyanate) to 3,5-difluorophenol is 100:(106-118).

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