Multifunctional rubber emulsion hydrogenation catalyst, preparation method and application thereof

Abstract

The present application relates to the technical field of high polymer materials, and discloses a multifunctional rubber emulsion hydrogenation catalyst, a preparation method and application thereof.The preparation method comprises the following steps: (1) preparing a catalyst intermediate product; (2) preparing the multifunctional rubber emulsion hydrogenation catalyst.The multifunctional rubber emulsion hydrogenation catalyst prepared by the present application can catalyze the hydrogenation of the emulsion of diene polymer materials together with hydrazine hydrate and hydrogen peroxide, and the hydrogenation degree of the prepared hydrogenated polymer materials is obviously improved, and the gel content is also improved.The multifunctional rubber emulsion hydrogenation catalyst prepared by the present application can also be used as a reactive antioxidant to improve the aging resistance of polymer materials.For rubber composites filled with SiO2 fillers, the multifunctional rubber emulsion hydrogenation catalyst prepared by the present application can also be used as a dispersant to improve the interaction between the SiO2 fillers and the matrix and improve the dispersion performance of the SiO2 fillers in the rubber composites.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a multifunctional rubber emulsion hydrogenation catalyst, a preparation method and an application thereof. Background Art

[0002] The hydrogenation methods for diene polymer materials are generally solution hydrogenation and emulsion hydrogenation. Solution hydrogenation often faces environmental and safety issues associated with the use of organic solvents, precious metal catalysts, and hydrogen. Therefore, emulsion hydrogenation has become a research hotspot. Among them, imide hydrogenation is achieved by a reduction reaction between imides and carbon-carbon double bonds. Imides (also known as amines) are active intermediates in the hydrogenation reaction and are highly active, but their survival time is relatively short. When imides hydrogenate unsaturated carbon-carbon double bonds in diene polymers using an emulsion as the reaction medium, they are mainly derived from hydrazine hydrate. Under metal ion catalysis, hydrazine hydrate is easily oxidized by oxidants to form imide active centers. After the imides encounter the unsaturated polymer to form a cyclic transition state, they hydrogenate the unsaturated polymer. The method of hydrogenating diene polymers via imides is an attractive alternative because it can avoid the requirement for hydrogenation equipment in traditional catalytic hydrogenation processes. Wideman first used imides as catalytic active centers to hydrogenate NBR (nitrile butadiene rubber) to produce HNBR (hydrogenated nitrile butadiene rubber). By treating the polymer with emulsion hydrogenation, a saturated polymer in emulsion form was obtained. The hydrogenation was carried out in the presence of hydrazine hydrate, an oxidant, and a copper ion catalyst. This process did not require hydrogen, meaning it did not require a pressure vessel, an organic solvent, or a precious metal catalyst. However, when using the imide hydrogenation method to catalytically hydrogenate a diene polymer emulsion, hydrogen peroxide as a catalyst produces oxygen-containing free radicals during the reaction, resulting in a high gel content in the hydrogenated product. Furthermore, imides are prone to side reactions during the reaction, resulting in a low degree of hydrogenation in the emulsion hydrogenation product and low reaction efficiency.

[0003] To address the challenges of imide hydrogenation, several research groups at home and abroad have explored catalyst systems and gel inhibition for the preparation of HNBR from imides. Zhou Shuqin et al. used a hydrazine hydrate / hydrogen peroxide / boric acid catalytic system to hydrogenate NBR latex to produce HNBR. Introducing a gel inhibitor into the hydrogenation system effectively blocked molecular chain crosslinking, reducing the gel content to approximately 3%. However, the emulsion hydrogenation system still requires the addition of a gel inhibitor to reduce the gel content, which increases the likelihood of material performance degradation. Ou Haoming used a hydrazine hydrate / hydrogen peroxide / selenium powder catalyst system for the catalytic hydrogenation of NBR emulsions and studied the reaction kinetics of imide hydrogenation, deriving the hydrogenation kinetic equation and activation energy. Gracelie et al. used a hydrazine hydrate / selenium powder / oxygen catalyst system to hydrogenate NBR emulsions and studied the reaction kinetics, achieving highly hydrogenated HNBR. However, the gelation problem in the preparation of HNBR from imides remains unsolved. Increasing the degree of hydrogenation also increases the gel content of the system, necessitating further research into the gelation issue. Catalyst selection is crucial for achieving a high degree of hydrogenation and low gel content in the hydrogenation of NBR emulsions, and for promoting their large-scale production and commercialization. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a multifunctional rubber emulsion hydrogenation catalyst and a preparation method and application thereof.

[0005] In order to achieve the above object, the technical solution of the present invention is: a method for preparing a multifunctional rubber emulsion hydrogenation catalyst, comprising the following steps:

[0006] (1) Preparing a catalyst intermediate product: dissolving sodium hydroxide in deionized water and mixing with a first additive, stirring thoroughly, and heating to 40-80° C. and maintaining for 0.5-1 hour to obtain a sodium salt solution; then dissolving a second additive in anhydrous ethanol, slowly adding the dissolved second additive to the sodium salt solution dropwise, and maintaining the solution at 40-80° C. for 3-8 hours to obtain a dark red liquid; cooling to room temperature, extracting, collecting the alcohol-water solution, adding hydroquinone to the alcohol-water solution, removing the solvent by rotary evaporation, washing, and drying to obtain a pink powder, which is the catalyst intermediate product; the first additive is a compound containing both two carboxyl groups and an amino group, and the second additive is an isothiocyanate compound having an N=C=S structure;

[0007] (2) Preparing a multifunctional rubber emulsion hydrogenation catalyst: dissolving the catalyst intermediate product prepared in step (1) in deionized water to prepare a catalyst intermediate product aqueous solution, heating the mixture to 40-80° C., dissolving a third additive in deionized water, and dripping the dissolved additive into the catalyst intermediate product aqueous solution, stirring and reacting at 40-80° C. for 4-10 hours, standing and cooling to room temperature, filtering, washing, and vacuum drying to obtain an off-white powder, which is a multifunctional rubber emulsion hydrogenation catalyst; the third additive is a metal ion compound or a rare earth element compound, the metal ion compound is selected from one or more of copper chloride, copper sulfate, magnesium chloride, magnesium sulfate, aluminum chloride, aluminum sulfate, zinc chloride, and zinc sulfate, and the rare earth element compound is selected from one or more of neodymium chloride hexahydrate, lanthanum chloride hexahydrate, cerium chloride hexahydrate, and samarium chloride and praseodymium chloride hexahydrate.

[0008] Furthermore, in step (1), the first additive is selected from glutamic acid or aspartic acid, and the second additive is selected from one of allyl isothiocyanate (AITC), benzyl isothiocyanate (BITC), and phenylethyl isothiocyanate (PEITC).

[0009] Furthermore, in step (1), the molar volume ratio of the sodium hydroxide to the deionized water is (0.2-0.3) mol: 80 mL, the molar volume ratio of the sodium hydroxide to the first additive is (2-3): 1, the molar volume ratio of the second additive to anhydrous ethanol is (0.1-0.2) mol: 20 mL, the molar ratio of the first additive to the second additive is 1: (1-2), and the mass ratio of the hydroquinone to the alcohol aqueous solution is 1: (600-800).

[0010] Furthermore, the extraction solvent in step (1) is selected from ether or chloroform.

[0011] Furthermore, the rotary evaporation temperature in step (1) is 60-80°C, the anhydrous ethanol is centrifuged and washed, and vacuum dried at 40-60°C to constant weight to obtain a pink powder.

[0012] Furthermore, the molar volume ratio of the catalyst intermediate product to deionized water in step (2) is (0.4-0.5) mol: 800 mL, and the molar volume ratio of the third additive to deionized water is 0.4 mol: 800 mL; the molar ratio of the catalyst intermediate product to the third additive is (2-3): 1.

[0013] Further, step (2) is stirred at 40-80°C and 240r / min for 4-10 hours, allowed to stand and cool to room temperature, filtered, washed with deionized water, and vacuum dried at 40°C to constant weight to obtain an off-white powder.

[0014] The multifunctional rubber emulsion hydrogenation catalyst is prepared according to the preparation method.

[0015] The invention relates to an application of the multifunctional rubber emulsion hydrogenation catalyst in the preparation of HNBR by hydrogenation reaction of NBR emulsion.

[0016] A use of the multifunctional rubber emulsion hydrogenation catalyst as an antioxidant in the preparation of rubber composite materials.

[0017] A use of the multifunctional rubber emulsion hydrogenation catalyst as a dispersant in the preparation of rubber composite materials.

[0018] The beneficial effects of the present invention are as follows: the multifunctional rubber emulsion hydrogenation catalyst prepared by the present invention is used together with hydrazine hydrate and hydrogen peroxide to catalyze the hydrogenation of an emulsion of a diene polymer material, and the hydrogenated polymer material thus prepared has a significantly improved degree of hydrogenation and an improved gel content. The multifunctional rubber emulsion hydrogenation catalyst prepared by the present invention can also be used as a reactive antioxidant that is resistant to volatility and extraction to improve the aging resistance of the polymer material. For rubber composite materials filled with SiO2 fillers, the multifunctional rubber emulsion hydrogenation catalyst prepared by the present invention can also be used as a dispersant to improve the interaction between the SiO2 filler and the matrix, thereby improving the dispersion performance of the SiO2 filler in the rubber composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is the infrared spectra of the multifunctional rubber emulsion hydrogenation catalysts prepared in Examples 1 to 6;

[0020] Figure 2 is a curve showing the change of elastic modulus G' value with strain of the NBR / SiO2 composite materials prepared in Examples 13 to 14;

[0021] Figure 3 is the ΔG′ value of the NBR / SiO2 composite materials prepared in Examples 13 to 14;

[0022] Figure 4 is a SEM image of the NBR / SiO2 composite material prepared in Example 13;

[0023] Figure 5 This is an SEM image of the NBR / SiO2 composite material prepared in Example 14. DETAILED DESCRIPTION

[0024] The XSM-500 torque rheometer in the present invention was purchased from Shanghai Kechuang Rubber and Plastic Machinery Equipment Co., Ltd.

[0025] The mixing mill BL-6175BL was purchased from Baolun Precision Testing Instrument Co., Ltd.

[0026] Example 1:

[0027] A method for preparing a multifunctional rubber emulsion hydrogenation catalyst comprises the following steps:

[0028] 1) At room temperature, 8.41 g (0.202 mol) of sodium hydroxide and 80 mL of deionized water were dissolved in a 250 mL three-necked flask equipped with a mechanical stirrer and a reflux condenser. After the sodium hydroxide was completely dissolved, 14.86 g (0.1 mol) of glutamic acid was added. The mixture was heated to 40°C in an oil bath and stirred at 240 rpm for 30 min to allow the glutamic acid and sodium hydroxide to fully react and convert into sodium glutamate, thereby preparing a sodium glutamate solution. 13.06 g (0.129 mol) of allyl isothiocyanate was dissolved in 20 mL of anhydrous ethanol and slowly added dropwise to the sodium glutamate solution through a constant pressure funnel. The reaction was continued at 40 ° C for 3 hours to obtain a dark red liquid. After cooling to room temperature, the reaction mixture was transferred to a 250 mL separatory funnel and extracted with chloroform until the lower chloroform layer was colorless. The upper alcohol aqueous solution was collected, 0.1 g of hydroquinone was added to the alcohol aqueous solution, and then the solvent was removed by rotary evaporation at 70 ° C. The crude product was centrifuged and washed with anhydrous ethanol until the upper washing liquid was colorless. It was then vacuum dried at 50 ° C to constant weight to obtain a catalyst intermediate powder.

[0029] 2) Weigh 23.80g (0.082mol) of the catalyst intermediate product and dissolve it in 160mL of deionized water to prepare an aqueous solution of the catalyst intermediate product. Stir and heat to 40°C at 240r / min. Weigh 14.35g of neodymium chloride hexahydrate (0.040mol) and dissolve it in 80mL of deionized water. Then place it in a constant pressure funnel and slowly add it dropwise to the aqueous solution of the catalyst intermediate product. The solution is added dropwise for about 45 minutes. Then, stir and react at 40°C at 240r / min for 6 hours. Let it stand and cool to room temperature. Filter it using a G4 sand core funnel. Wash the filter residue repeatedly with deionized water. Dry the filter residue in vacuum at 40°C for 8 hours to obtain an off-white powder, which is the multifunctional rubber emulsion hydrogenation catalyst S1. The molecular structure of S1 is determined by infrared spectroscopy, as shown in FIG. Figure 1 As shown, the content of each element in S1 was determined using an element analyzer, see 1.

[0030] Example 2:

[0031] A method for preparing a multifunctional rubber emulsion hydrogenation catalyst comprises the following steps:

[0032] 1) At room temperature, 8.41 g (0.202 mol) of sodium hydroxide and 80 mL of deionized water were dissolved in a 250 mL three-necked flask equipped with a mechanical stirrer and a reflux condenser. After the sodium hydroxide was completely dissolved, 14.86 g (0.1 mol) of glutamic acid was added. The mixture was heated to 80°C in an oil bath and stirred at 240 rpm for 30 min to allow the glutamic acid and sodium hydroxide to fully react and convert into sodium glutamate, thereby preparing a sodium glutamate solution. 13.06 g (0.129 mol) of allyl isothiocyanate was dissolved in 20 mL of anhydrous ethanol and slowly added dropwise to the sodium glutamate solution through a constant pressure funnel. The reaction was continued at 80 ° C for 3 hours to obtain a dark red liquid. After cooling to room temperature, the reaction mixture was transferred to a 250 mL separatory funnel and extracted with chloroform until the lower chloroform layer was colorless. The upper alcohol aqueous solution was collected, 0.1 g of hydroquinone was added to the alcohol aqueous solution, and then the solvent was removed by rotary evaporation at 70 ° C. The crude product was centrifuged and washed with anhydrous ethanol until the upper washing liquid was colorless. It was vacuum dried at 50 ° C to constant weight to obtain a powder of the catalyst intermediate product.

[0033] 2) Weigh 23.80g (0.082mol) of the catalyst intermediate product and dissolve it in 160mL of deionized water to prepare a catalyst intermediate product aqueous solution. Stir and heat it to 80°C at 240r / min. Weigh 14.35g of neodymium chloride hexahydrate (0.040mol) and dissolve it in 80mL of deionized water. Then place it in a constant pressure funnel and slowly add it dropwise to the catalyst intermediate product aqueous solution. The dripping is completed in about 45 minutes. Then stir and react at 80°C and 240r / min for 6 hours. Let it stand and cool to room temperature. Use a G4 sand core funnel to filter. Wash the filter residue repeatedly with deionized water. Place the filter residue at 50°C and vacuum dry for 8h to obtain an off-white powder, which is the multifunctional emulsion hydrogenation catalyst S2. The molecular structure of S2 is determined by infrared spectroscopy, as shown in FIG. Figure 1 As shown in Table 1, the content of each element in S2 was determined using an element analyzer.

[0034] Example 3:

[0035] A method for preparing a multifunctional rubber emulsion hydrogenation catalyst comprises the following steps:

[0036] 1) At room temperature, 8.41 g (0.202 mol) of sodium hydroxide and 80 mL of deionized water were dissolved in a 250 mL three-necked flask equipped with a mechanical stirrer and a reflux condenser. After the sodium hydroxide was completely dissolved, 14.86 g (0.1 mol) of glutamic acid was added. The mixture was heated to 80°C in an oil bath and stirred at 240 rpm for 30 min to allow the glutamic acid and sodium hydroxide to fully react and convert into sodium glutamate, thereby preparing a sodium glutamate solution. 13.06 g (0.129 mol) of allyl isothiocyanate was dissolved in 20 mL of anhydrous ethanol and slowly added dropwise to the sodium glutamate solution through a constant pressure funnel. The reaction was continued at 80 ° C for 8 hours to obtain a dark red liquid. The heating was turned off and the mixture was cooled to room temperature. The reaction mixture was transferred to a 250 mL separatory funnel and extracted with chloroform until the lower chloroform layer was colorless. The upper alcohol aqueous solution was collected, 0.1 g of hydroquinone was added to the alcohol aqueous solution, and then the solvent was removed by rotary evaporation at 70 ° C. The crude product was centrifuged and washed with anhydrous ethanol until the upper washing liquid was colorless. It was vacuum dried at 50 ° C to constant weight to obtain a catalyst intermediate powder.

[0037] 2) Weigh 23.80g (0.082mol) of the catalyst intermediate product and dissolve it in 160mL of deionized water to prepare an aqueous solution of the catalyst intermediate product. Stir and heat to 80°C at 240r / min. Weigh 6.38g of copper sulfate (0.040mol) and dissolve it in 80mL of deionized water. Then place it in a constant pressure funnel and slowly add it dropwise to the aqueous solution of the catalyst intermediate product. The dripping is completed in about 45 minutes. Then stir and react at 80°C at 240r / min for 8 hours. Let it stand and cool to room temperature. Use a G4 sand core funnel to filter. Wash the filter residue repeatedly with deionized water. Place the filter residue at 50°C and vacuum dry for 8 hours to obtain an off-white powder, which is the multifunctional rubber emulsion hydrogenation catalyst S3. The molecular structure of S3 is determined by infrared spectroscopy, as shown in FIG. Figure 1 As shown in Table 1, the content of each element in S3 was determined using an element analyzer.

[0038] Example 4:

[0039] A method for preparing a multifunctional rubber emulsion hydrogenation catalyst comprises the following steps:

[0040] 1) At room temperature, 8.41 g (0.202 mol) of sodium hydroxide and 80 mL of deionized water were dissolved in a 250 mL three-necked flask equipped with a mechanical stirrer and a reflux condenser. After the sodium hydroxide was completely dissolved, 14.86 g (0.1 mol) of glutamic acid was added. The mixture was heated to 40°C in an oil bath and stirred at 240 rpm for 30 min to allow the glutamic acid to fully react with the sodium hydroxide to convert into sodium glutamate, thereby preparing a sodium glutamate solution. 13.06 g (0.129 mol) of allyl isothiocyanate was dissolved in 20 mL of anhydrous ethanol and slowly added dropwise to the sodium glutamate solution through a constant pressure funnel. The reaction was continued at 80 ° C for 8 hours to obtain a dark red liquid. After cooling to room temperature, the reaction mixture was transferred to a 250 mL separatory funnel and extracted with chloroform until the lower chloroform layer was colorless. The upper alcohol aqueous solution was collected, 0.1 g of hydroquinone was added to the alcohol aqueous solution, and then the solvent was removed by rotary evaporation at 70 ° C. The crude product was centrifuged and washed with anhydrous ethanol until the upper washing liquid was colorless. It was then vacuum dried at 50 ° C to constant weight to obtain a catalyst intermediate powder.

[0041] 2) Weigh 23.80g (0.082mol) of the catalyst intermediate product and dissolve it in 160mL of deionized water to prepare an aqueous solution of the catalyst intermediate product. Stir and heat to 40°C at 240r / min. Weigh 6.38g of copper sulfate (0.040mol) and dissolve it in 80mL of deionized water. Then place it in a constant pressure funnel and slowly add it dropwise to the aqueous solution of the catalyst intermediate product. The dripping is completed in about 45 minutes. Then stir and react at 40°C at 240r / min for 8 hours. Let it stand and cool to room temperature. Use a G4 sand core funnel to filter. Wash the filter residue repeatedly with deionized water. Place the filter residue at 50°C and vacuum dry for 8 hours to obtain an off-white powder, which is the multifunctional rubber emulsion hydrogenation catalyst S4. The molecular structure of S4 is determined by infrared spectroscopy, as shown in FIG. Figure 1 As shown in Table 1, the content of each element in S4 was determined using an element analyzer.

[0042] Example 5:

[0043] A method for preparing a multifunctional rubber emulsion hydrogenation catalyst comprises the following steps:

[0044] 1) At room temperature, 8.41 g (0.202 mol) of sodium hydroxide and 80 mL of deionized water were dissolved in a 250 mL three-necked flask equipped with a mechanical stirrer and a reflux condenser. After the sodium hydroxide was completely dissolved, 14.86 g (0.1 mol) of glutamic acid was added to the flask. The flask was heated to 50°C in an oil bath and stirred at 240 rpm for 30 min to allow the glutamic acid to fully react with the sodium hydroxide to convert into sodium glutamate, thereby preparing a sodium glutamate solution. 13.06 g (0.129 mol) of allyl isothiocyanate was dissolved in 20 mL of anhydrous ethanol and slowly added dropwise to the sodium glutamate solution through a constant pressure funnel. The reaction was continued at 80 ° C for 6 hours to obtain a dark red liquid. After cooling to room temperature, the reaction mixture was transferred to a 250 mL separatory funnel and extracted with chloroform until the lower chloroform layer was colorless. The upper alcohol aqueous solution was collected, 0.1 g of hydroquinone was added to the alcohol aqueous solution, and then the solvent was removed by rotary evaporation at 70 ° C. The crude product was centrifuged and washed with anhydrous ethanol until the upper washing liquid was colorless. It was vacuum dried at 50 ° C to constant weight to obtain a catalyst intermediate powder.

[0045] 2) Weigh 23.80g (0.082mol) of the catalyst intermediate product and dissolve it in 160mL of deionized water to prepare an aqueous solution of the catalyst intermediate product. Stir and heat to 50°C at 240r / min. Weigh 6.38g of copper sulfate (0.040mol) and dissolve it in 80mL of deionized water. Then place it in a constant pressure funnel and slowly add it dropwise to the aqueous solution of the catalyst intermediate product. The dripping is completed in about 45 minutes. Then stir and react at 50°C at 240r / min for 6 hours. Let it stand and cool to room temperature. Use a G4 sand core funnel to filter. Wash the filter residue repeatedly with deionized water. Place the filter residue at 50°C and vacuum dry for 8 hours to obtain an off-white powder, which is the multifunctional rubber emulsion hydrogenation catalyst S5. The molecular structure of S5 is determined by infrared spectroscopy, as shown in FIG. Figure 1 As shown in Table 1, the content of each element in S5 was determined using an element analyzer.

[0046] Example 6:

[0047] A method for preparing a multifunctional rubber emulsion hydrogenation catalyst comprises the following steps:

[0048] 1) At room temperature, 8.41 g (0.202 mol) of sodium hydroxide and 80 mL of deionized water were dissolved in a 250 mL three-necked flask equipped with a mechanical stirrer and a reflux condenser. After the sodium hydroxide was completely dissolved, 14.86 g (0.1 mol) of glutamic acid was added. The mixture was heated to 50°C in an oil bath and stirred at 240 rpm for 30 min to allow the glutamic acid to fully react with the sodium hydroxide to convert into sodium glutamate, thereby preparing a sodium glutamate solution. 13.06 g (0.129 mol) of allyl isothiocyanate was dissolved in 20 mL of anhydrous ethanol and slowly added dropwise to the sodium glutamate solution through a constant pressure funnel. The reaction was continued at 80 ° C for 4 hours to obtain a dark red liquid. After cooling to room temperature, the reaction mixture was transferred to a 250 mL separatory funnel and extracted with chloroform until the lower chloroform layer was colorless. The upper alcohol aqueous solution was collected, 0.1 g of hydroquinone was added to the alcohol aqueous solution, and then the solvent was removed by rotary evaporation at 70 ° C. The crude product was centrifuged and washed with anhydrous ethanol until the upper washing liquid was colorless. It was then vacuum dried at 50 ° C to constant weight to obtain a catalyst intermediate powder.

[0049] 2) Weigh 23.80g (0.082mol) of the catalyst intermediate product and dissolve it in 160mL of deionized water to prepare a catalyst intermediate product aqueous solution. Stir and heat it to 50°C at 240r / min. Weigh 6.38g of copper sulfate (0.040mol) and dissolve it in 80mL of deionized water. Then place it in a constant pressure funnel and slowly add it dropwise to the catalyst intermediate product aqueous solution. The dripping is completed in about 45 minutes. Then stir and react at 50°C at 240r / min for 4 hours. Let it stand and cool to room temperature. Use a G4 sand core funnel to filter. Wash the filter residue repeatedly with deionized water. Place the filter residue at 50°C and vacuum dry for 8 hours to obtain an off-white powder, which is the multifunctional rubber emulsion hydrogenation catalyst S6. The molecular structure of S6 is determined by infrared spectroscopy, as shown in FIG. Figure 1 As shown in Table 1, the content of each element in S6 was determined using an element analyzer.

[0050] Table 1 Elemental analysis of the multifunctional rubber emulsion hydrogenation catalyst prepared in Examples 1 to 6 (mass percentage %)

[0051] N％ C％ H％ S％ S1 6.98 25.33 4.0 7.31 S2 7.29 28.49 3.9 7.46 S3 6.55 24.98 3.8 7.39 S4 6.67 27.44 4.1 7.30 S5 6.41 24.72 4.0 7.20 S6 7.18 28.11 3.9 7.11

[0052] The following Examples 7 to 12 and Comparative Examples 1 to 2 are used to describe the application of the prepared multifunctional rubber emulsion hydrogenation catalyst in the hydrogenation reaction of NBR emulsion to prepare HNBR.

[0053] Example 7:

[0054] A three-necked flask containing 100 g of NBR (acrylonitrile mass fraction of 33%, solid content of 22%) latex was placed in an oil bath at 35° C., and then 68.21 g of hydrazine hydrate (the molar ratio of hydrazine hydrate to the double bonds of the NBR molecular chain was 4:1) and 0.03 g of the multifunctional rubber latex hydrogenation catalyst S1 prepared in Example 1 (the molar ratio of the catalyst S1 to the double bonds of the NBR molecular chain was 2.5×10 -4 ∶1), mechanically stirred at 200 r / min for 10 min, 123.97 g of hydrogen peroxide (the molar ratio of hydrogen peroxide to the double bond of the NBR molecular chain is 4:1) was slowly added dropwise from a constant pressure funnel. After the hydrogen peroxide was completely added, the mixture was stirred at 35°C and 200 r / min for 2 h, and then a 20% by mass calcium chloride aqueous solution flocculent emulsion was added. The mixture was washed with deionized water and vacuum dried at 60°C to constant weight to prepare HNBR, which was numbered HNBR-1. The degree of hydrogenation of HNBR-1 was tested and calculated by infrared spectroscopy, and the gel content of HNBR-1 was determined according to SH / T 1050-2014 petrochemical industry standard. The results are shown in Table 2.

[0055] Examples 8 to 12:

[0056] The method was the same as in Example 7, except that the multifunctional rubber emulsion hydrogenation catalyst S1 was replaced with the multifunctional rubber emulsion hydrogenation catalysts S2 to S6 prepared in Examples 2 to 6. The resulting HNBRs were numbered HNBR-2 to HNBR-6. The hydrogenation degrees and gel contents of HNBR-2 to HNBR-6 are shown in Table 2.

[0057] Comparative Example 1:

[0058] The method was the same as in Example 7, except that the multifunctional rubber latex hydrogenation catalyst S1 was replaced with copper sulfate (CuSO4) to obtain HNBR, designated HNBR-7. The degree of hydrogenation and gel content of HNBR-7 are shown in Table 2.

[0059] Comparative Example 2:

[0060] The method was the same as in Example 7, except that the multifunctional rubber latex hydrogenation catalyst S1 was replaced with neodymium chloride (NdCl3) to obtain HNBR, designated HNBR-8. The degree of hydrogenation and gel content of HNBR-8 are shown in Table 2.

[0061] Table 2 Degree of hydrogenation and gel content of HNBR prepared in Examples 7-12 and Comparative Examples 1-2

[0062]

[0063]

[0064] As can be seen from Table 2, compared with Comparative Examples 1 and 2, the multifunctional rubber emulsion hydrogenation catalyst prepared by reacting glutamic acid, allyl isothiocyanate, a metal ion compound or a rare earth element compound in the present invention can be used for the hydrogenation reaction of NBR diene polymer emulsion, and has a higher degree of hydrogenation and a lower gel content. The multifunctional rubber emulsion hydrogenation catalyst of the present invention can improve the gel content of the reaction system while increasing the degree of hydrogenation of the diene polymer emulsion hydrogenation reaction system.

[0065] Example 13:

[0066] The multifunctional rubber emulsion hydrogenation catalyst S5 prepared in Example 5 was used as an antioxidant to improve the aging resistance of polymer materials in the preparation of NBR rubber composite materials. The mixing process was carried out according to the formula in Table 3 and the mixing was carried out using an XSM-500 torque rheometer. In the first mixing process, the starting temperature of the torque rheometer was 70°C and the rotor speed was 60 r / min. NBR raw rubber was added for mixing. When the torque curve changed in a horizontal direction, it indicated that the rubber had been mixed evenly. Zinc oxide (ZnO), stearic acid (SA) and antioxidant (S5) were added to the torque rheometer respectively. When the torque curve extended in a horizontal direction, half of SiO2 and silane coupling agent KH560 were added. The torque curve and mixing time were observed until the torque curve extended in a horizontal direction. The remaining half of SiO2 and silane coupling agent KH560 were added to the torque rheometer until the torque curve extended in a horizontal direction. Mixing was continued for 1 minute, mixing was stopped, and the rubber was discharged and cooled. The second mixing process: The torque rheometer temperature was set at 90°C and the rotor speed at 60 rpm. The rubber strip mixed in the first mixing stage was added and mixed. When the torque curve showed a horizontal extension, accelerator NS and sulfur (S) were added to the torque rheometer. Mixing was continued for 2 minutes after the torque curve showed a horizontal extension. Mixing was stopped, and the rubber was drained and cooled. The rubber was drained on a BL-6175BL open mill, with three cycles of left and right cutting and refining, and six cycles of thinning. Finally, the rubber was removed, cooled, and stored. The vulcanization characteristic curve of the rubber was tested according to the national standard GB / T 16584-1996, and the vulcanization time was determined based on the vulcanization curve t90. The strength test specimens were vulcanized on a flatbed vulcanizer at a vulcanization temperature of 160°C and a vulcanization pressure of 15 MPa to produce an NBR / SiO2 composite containing a multifunctional catalyst.

[0067] Example 14:

[0068] The multifunctional rubber latex hydrogenation catalyst S5 prepared in Example 5 was used as a dispersant instead of a silane coupling agent in the preparation of an NBR rubber composite material to improve the interaction between the filler and the rubber matrix and enhance the dispersion of the filler in the NBR rubber composite material. Mixing was performed according to the formula in Table 3 and using an XSM-500 torque rheometer. The first mixing process was as follows: the internal mixer had an initial temperature of 70°C and a rotor speed of 60 r / min. NBR raw rubber was added and mixed. When the torque curve showed a horizontal change, it indicated that the rubber had been mixed uniformly. Zinc oxide (ZnO), stearic acid (SA), and an antioxidant (S5) were added to the torque rheometer, respectively. When the torque curve showed a horizontal extension, half of the SiO2 and dispersant (S5) were added. The torque curve and mixing time were observed until the torque curve showed a horizontal extension. The remaining half of the SiO2 and dispersant (S5) were then added to the torque rheometer until the torque curve showed a horizontal extension. Mixing was continued for 1 minute, then mixing was stopped, and the rubber was drained and cooled. The second mixing process: the torque rheometer temperature is 90 ° C, the rotor speed is 60 r / min, and the rubber strip mixed in the first stage is added and pressurized. When the torque curve extends in the horizontal direction, the accelerator NS and sulfur (S) are added to the torque rheometer. After the torque curve extends in the horizontal direction, the mixing is continued for 2 minutes. The mixing is stopped and the rubber is discharged and cooled. The rubber is discharged on the open mixing mill BL-6175BL, and the left and right cutting and refining are repeated 3 times, and the thin pass is repeated 6 times. Finally, the sheet is removed, cooled, and the rubber is stored. According to the national standard GB / T16584-1996, the vulcanization characteristic curve of the rubber is tested, and the vulcanization time is determined according to the vulcanization curve t90; the strength test piece is vulcanized on a flat vulcanizer at a vulcanization temperature of 160 ° C and a vulcanization pressure of 15 MPa to prepare an NBR / SiO2 composite material.

[0069] Comparative Example 3:

[0070] The method is consistent with that of Example 13, except that antioxidant 4020 is used instead of antioxidant (S5) to prepare an NBR / SiO2 composite material containing antioxidant 4020.

[0071] Comparative Example 4:

[0072] The method is consistent with that of Example 13, except that antioxidant 445 is used instead of antioxidant (S5) to prepare an NBR / SiO2 composite material containing antioxidant 445.

[0073] Table 3 Formulas of Examples 13-14 and Comparative Examples 3-4 (by mass)

[0074] Example 13 Example 14 Comparative Example 3 Comparative Example 4 NBR raw rubber 100 100 100 100 <![CDATA[SiO2]]> 40 40 40 40 ZnO 5 5 5 5 SA 1 1 1 1 S 1.5 1.5 1.5 1.5 Accelerator NS 1 1 1 1 Antioxidant (S5) 2 2 - - Antioxidant 4020 - - 2 - Antioxidant 445 - - - 2 Silane coupling agent KH560 4 - 4 4 Dispersant (S5) - 4 - -

[0075] The thermal stability, aging resistance, extraction resistance and volatility resistance of the NBR / SiO2 composite materials prepared in Example 13 and Comparative Examples 3 to 4 were tested.

[0076] Thermal stability and volatility resistance were tested using thermogravimetric analysis (TGA). The TGA test method was as follows: under nitrogen atmosphere, the temperature range was 30°C to 600°C, and the heating rate was 10°C / min. The national standard GB-T7762-2003 was used to test aging resistance under the condition of aging at 100°C for 7 days. The aging resistance of the NBR / SiO2 composite material was expressed by the mechanical property retention rate after aging (performance retention rate = performance after aging / performance before aging × 100%). The extraction resistance test method was as follows: the NBR / SiO2 composite material was extracted in a Soxhlet extractor using methanol as the solvent. After 72 hours of extraction, the extracted sample was dried and its aging performance was tested. The test results are shown in Table 4. T in Table 4 5％ and T 10％ It indicates the migration loss rate of small molecules in NBR / SiO2 composite materials and is used to indicate the volatility resistance of antioxidants in NBR / SiO2 composite materials. onset It indicates the temperature at which NBR / SiO2 composite materials begin to degrade and is used to indicate the thermal stability of NBR / SiO2 composite materials.

[0077] Table 4 Performance comparison of Example 13 and Comparative Examples 3-4

[0078]

[0079] The dispersibility of SiO2 in the NBR / SiO2 composite materials prepared in Examples 13 to 14 and the interaction between SiO2 and the rubber matrix NBR in the NBR / SiO2 composite materials were tested.

[0080] The interaction between SiO2 and the rubber matrix NBR in the NBR / SiO2 composite material was tested using a rubber process analyzer (RPA). The RPA test conditions were as follows: strain sweep mode conditions: scanning temperature 60°C, frequency 1 Hz, strain range 0.28% to 200%, such as Figure 2 and Figure 3 shown.

[0081] The dispersion of SiO2 in NBR / SiO2 composite material was observed by scanning electron microscopy (SEM). The SEM test conditions were: acceleration voltage of 5kV, and the microscopic morphology of the cross section of NBR / SiO2 composite material was observed. The test results are as follows: Figure 4 and Figure 5 shown.

[0082] As shown in Table 4, the T onsetThe values ​​of Example 3 and Example 4 are higher than those of Example 3, indicating that the multifunctional rubber emulsion hydrogenation catalyst prepared by the present invention effectively improves the thermal stability of the material as an antioxidant. 5％ and T 10％ The results are both higher than those in Comparative Examples 3 and 4, indicating that the small molecule migration loss rate in the NBR / SiO2 composite material with the addition of the multifunctional rubber emulsion hydrogenation catalyst is lower than that in the NBR / SiO2 composite material with the addition of antioxidant 4020 and antioxidant 445. Since the NBR / SiO2 composite material formula is identical except for the type of antioxidant, the other components are identical. Therefore, it is shown that the multifunctional rubber emulsion hydrogenation catalyst S5 added in Example 13 has better volatility resistance than the antioxidant 4020 and antioxidant 445 in Comparative Examples 3 and 4. After 7 days of thermal oxidative aging at 100°C, the performance retention rates of the tensile strength and elongation at break of the NBR / SiO2 composite material with the addition of the multifunctional rubber emulsion hydrogenation catalyst S5 are significantly higher than those of the composite materials prepared in Comparative Examples 3 and 4 with the addition of antioxidant 4020 and antioxidant 445, indicating that the introduction of the multifunctional rubber emulsion hydrogenation catalyst prepared by the present invention as an antioxidant can effectively improve the aging resistance of the material. At the same time, after 72 hours of methanol extraction, the degree of decrease in the mechanical property retention rate of the NBR / SiO2 composite material prepared in Example 13 after extraction is also lower than that of the composite materials prepared in Comparative Examples 3 and 4, indicating that the multifunctional rubber emulsion hydrogenation catalyst has good extraction resistance as an antioxidant.

[0083] Depend on Figure 2 and Figure 3It can be seen that the elastic modulus G' of the NBR / SiO2 composite materials prepared in Examples 13 and 14 all showed a sharp downward trend with increasing strain, and the downward trend slowed down and stabilized in the later period. Under low strain, there is a large amount of inclusion glue in the composite material, the effective volume of the filler becomes larger, and the modulus is higher. As the strain increases, the SiO2 aggregates that form the inclusion glue are gradually broken, and the NBR originally wrapped by the inclusion glue is gradually released and participates in the deformation, which reduces the modulus. At the same time, the filler network structure formed by SiO2 in the composite material system is gradually destroyed, which reduces the G' value. Under high strain, the filler network structure in the composite material system is almost completely destroyed, and the G' value decreases by a smaller margin, remaining basically unchanged. Among them, the G' value of Example 14 is relatively low, indicating that the degree of destruction of the filler network structure formed by SiO2 in the composite material is relatively large. The strain dependence of the elastic modulus G' of the NBR / SiO2 composite material, namely the Payne effect, is studied using RPA to evaluate the dispersion of SiO2 in the NBR rubber matrix. Generally, the smaller the ΔG′ value (the difference between the highest and lowest elastic moduli), the weaker the Payne effect and the weaker the filler network formed by the filler, indicating that the filler is more evenly dispersed. The ΔG′ value of the NBR / SiO2 composite prepared in Example 14 is lower than that of the NBR / SiO2 composite prepared in Example 13. This indicates that under the same test conditions, the hydrogen bonding effect formed between the multifunctional rubber emulsion hydrogenation catalyst and the filler SiO2 is stronger, promoting the dispersion of the filler SiO2 in the NBR, weakening the formation of the filler network, and resulting in a lower ΔG′ value.

[0084] Depend on Figure 4 and Figure 5 It can be seen that in the NBR / SiO2 composite material prepared in Example 13, obvious SiO2 aggregates are dispersed on the cross-section of the composite material, indicating that the dispersion of SiO2 in the NBR / SiO2 composite material is poor. No obvious SiO2 aggregates are found in the NBR / SiO2 composite material prepared in Example 14, indicating that the multifunctional rubber emulsion hydrogenation catalyst prepared in the present invention can effectively improve the dispersion of filler SiO2 in the NBR / SiO2 composite material.

[0085] In summary, the multifunctional rubber emulsion hydrogenation catalyst prepared by the present invention can be used as a rubber emulsion hydrogenation catalyst to hydrogenate diene polymer materials together with hydrazine hydrate and hydrogen peroxide, effectively increasing the degree of hydrogenation of the product and correspondingly improving the gel content. Simultaneously, the multifunctional rubber emulsion hydrogenation catalyst prepared by the present invention can also be used as a reactive antioxidant, effectively improving the aging resistance of the rubber material and providing resistance to volatilization and extraction. For rubber composite materials filled with SiO2 fillers, the multifunctional rubber emulsion hydrogenation catalyst prepared by the present invention can also be used as a dispersant to effectively improve the dispersion performance of the SiO2 filler in the rubber composite material.

[0086] The above-described embodiments are only preferred solutions of the present invention and are not intended to limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solutions described in the claims.

Claims

1. A method for preparing a multifunctional rubber emulsion hydrogenation catalyst, characterized in that: The following steps are involved: (1) Preparation of a catalyst intermediate product: Sodium hydroxide is dissolved in deionized water and then mixed with a first additive, and the mixture is heated to 40-80°C and maintained at 40-80°C for 0.5-1h after being fully stirred to obtain a sodium salt solution. A second additive is then dissolved in anhydrous ethanol, and the mixture is slowly added dropwise to the sodium salt solution after dissolution, and maintained at 40-80°C for 3-8 hours to obtain a dark red liquid. The mixture is cooled to room temperature and then extracted, and the alcohol-water solution is collected. Hydroquinone is added to the alcohol-water solution, and the solvent is removed by rotary evaporation, washed, and dried to obtain a pink powder, which is the catalyst intermediate product. The first additive is a compound containing two carboxyl groups and an amino group, and the second additive is allyl isothiocyanate having an N=C=S structure. (2) Preparing a multifunctional rubber emulsion hydrogenation catalyst: dissolving the catalyst intermediate product prepared in step (1) in deionized water to prepare a catalyst intermediate product aqueous solution, heating the solution to 40-80°C, dissolving the third additive in deionized water, and dripping the dissolved additive into the catalyst intermediate product aqueous solution, stirring and reacting at 40-80°C for 4-10 hours, standing and cooling to room temperature, filtering, washing, and vacuum drying to obtain an off-white powder, which is a multifunctional rubber emulsion hydrogenation catalyst; the third additive is a metal ion compound or a rare earth element compound, the metal ion compound is selected from one or more of copper chloride, copper sulfate, magnesium chloride, magnesium sulfate, aluminum chloride, aluminum sulfate, zinc chloride, and zinc sulfate, and the rare earth element compound is selected from one or more of neodymium chloride hexahydrate, lanthanum chloride hexahydrate, cerium chloride hexahydrate, samarium chloride hexahydrate, and praseodymium chloride.

2. The preparation method of the multifunctional rubber emulsion hydrogenation catalyst according to claim 1, wherein: In step (1), the first additive is selected from glutamic acid or aspartic acid.

3. The preparation method of the multifunctional rubber emulsion hydrogenation catalyst according to claim 1, characterized in that: In step (1), the molar volume ratio of sodium hydroxide to deionized water is (0.2-0.3) mol: 80 mL, the molar volume ratio of sodium hydroxide to the first additive is (2-3): 1, the molar volume ratio of the second additive to anhydrous ethanol is (0.1-0.2) mol: 20 mL, the molar ratio of the first additive to the second additive is 1: (1-2), and the mass ratio of hydroquinone to the alcohol aqueous solution is 1: (600-800).

4. The preparation method of the multifunctional rubber emulsion hydrogenation catalyst according to claim 1, characterized in that: The extraction solvent in step (1) is selected from ether or chloroform; the rotary evaporation temperature in step (1) is 60-80°C, the anhydrous ethanol is centrifuged and washed, and vacuum dried at 40-60°C to constant weight to obtain a pink powder.

5. The preparation method of the multifunctional rubber emulsion hydrogenation catalyst according to claim 1, characterized in that: The molar volume ratio of the catalyst intermediate product to deionized water in step (2) is (0.4-0.5) mol:800 mL, the molar volume ratio of the third additive to deionized water is 0.4 mol:800 mL; and the molar ratio of the catalyst intermediate product to the third additive is (2-3):

1.

6. The preparation method of the multifunctional rubber emulsion hydrogenation catalyst according to claim 1, characterized in that: Step (2) stirring the reaction at 40-80°C and 240 r / min for 4-10 hours, standing and cooling to room temperature, filtering, washing the filter residue with deionized water, and vacuum drying at 40°C to constant weight to obtain an off-white powder.

7. The multifunctional rubber emulsion hydrogenation catalyst prepared according to the preparation method of claim 1.

8. the application of multifunctional rubber emulsion hydrogenation catalyst according to claim 7 in NBR emulsion hydrogenation reaction preparing HNBR.

9. Use of the multifunctional rubber emulsion hydrogenation catalyst according to claim 7 as an antioxidant in the preparation of rubber composite materials.

10. Use of the multifunctional rubber emulsion hydrogenation catalyst according to claim 7 as a dispersant in the preparation of rubber composite materials.

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