A method for preparing hydrogenated styrene-butadiene-styrene block polymer by using palladium-nickel carbonized resin as catalyst

Abstract

The present invention relates to the field of catalytic hydrogenation, and specifically relates to a method for preparing hydrogenated styrene-butadiene-styrene block polymer by using palladium-nickel carbonized resin as a catalyst. The technical key points are as follows: A method for preparing hydrogenated styrene-butadiene-styrene block polymer by using palladium-nickel carbonized resin as a catalyst, characterized in that carbonized resin is used as a carrier, and a palladium-nickel catalyst is loaded to form a palladium-nickel resin type hydrogenation catalyst. The elastomer SBS is catalytically hydrogenated by using this catalyst to obtain a hydrogenated styrene-butadiene-styrene block polymer, and the catalyst contains hydroxyl groups. The preparation process of the present invention follows the tenet of green chemistry, uses a heterogeneous catalyst to prepare SEBS with high hydrogenation degree and high selectivity, and solves the problems of poor selectivity of the catalyst, difficult separation, short lifespan, difficult product treatment, and complex process in the preparation of SEBS by traditional homogeneous catalysts.

Description

Technical Field

[0001] The present invention relates to the field of catalytic hydrogenation, and particularly to a method for preparing hydrogenated styrene-butadiene-styrene block copolymer by using palladium-nickel carbonized resin as catalyst. Background Art

[0002] SBS elastomers have the characteristics of plastics and rubbers, are easy to be thermoformed and processed, and have wide applications. However, due to the active chemical properties of double bonds in the polybutadiene segment, their aging resistance to oxygen, ozone, heat, light, etc. is poor, which greatly limits their applications in some specific environments. Therefore, selective hydrogenation of SBS to saturate the double bonds in the butadiene segment to prepare hydrogenated styrene-butadiene block copolymer (SEBS) can improve its aging resistance.

[0003] In the prior art, there are usually two methods of homogeneous catalysis and heterogeneous catalysis. Among them, homogeneous catalysts can achieve good hydrogenation degree in related fields, and the selectivity also reaches 100%. However, the cost is high, and it is difficult to separate, and the subsequent treatment of products is difficult. The heterogeneous catalyst and SBS are in two phases of glue liquid. The separation of products and the recovery of catalysts are relatively easy. However, the hydrogenation selectivity of the heterogeneous catalysts in the prior art is poor. When hydrogenating the butadiene segment, the benzene ring is likely to react with hydrogen to obtain by-products, which affects the performance of SEBS.

[0004] In view of the above defects of the existing hydrogenation catalytic reactions, based on the rich experience and professional knowledge in this kind of materials for many years, the inventor of the present invention, combined with theoretical analysis, carried out research and innovation to develop a method for preparing hydrogenated styrene-butadiene-styrene block copolymer by using palladium-nickel carbonized resin as catalyst. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preparing hydrogenated styrene-butadiene-styrene block copolymer by using palladium-nickel carbonized resin as catalyst, to solve the technical problems that the preparation of the above palladium-supported catalyst is complex, the hydrogenation selectivity of nickel catalyst for SBS is low, and the inappropriate catalyst preparation method causes the loss of rare earth elements, reduces the components of the catalyst, reduces the difficulty of catalyst separation, improves the product treatment efficiency, prolongs the service life of the catalyst, improves the catalytic efficiency, and has industrial value.

[0006] The above technical purpose of the present invention is achieved by the following technical solutions:

[0007] A method for preparing a hydrogenated styrene-butadiene-styrene block polymer by using a palladium-nickel carbonized resin catalyst is provided by the present invention. A carbonized resin is used as a carrier, and a palladium-nickel catalyst is loaded thereon to prepare a palladium-nickel resin-type hydrogenation catalyst. The elastomer SBS is catalytically hydrogenated by using this catalyst to obtain a hydrogenated styrene-butadiene-styrene block polymer. The catalyst contains hydroxyl groups. Figure 1 It is the infrared spectrum of hydroxyl groups.

[0008] The catalyst prepared by the present invention through the ion exchange method. By investigating the service life, after being reused 10 times, the conversion rate is above 86%, and the stability of the catalyst is improved, enabling the catalyst to have better stability.

[0009] Furthermore, for the palladium-nickel resin-type hydrogenation catalyst, calculated by mass percentage, palladium is used as the active component with a content of 3 - 6%, nickel is used as the auxiliary agent with a content of 3 - 10%, and the balance is carbonized resin.

[0010] Furthermore, the carbonized resin is obtained by carbonizing macroporous gel resin.

[0011] Furthermore, the carbonized resin is obtained by calcining a macroporous sulfonic acid cation exchange resin with an exchange capacity of 3.2 (mmol / g) H+. The carbonized resin obtained by calcining this resin still contains some hydroxyl groups. The existence of these hydroxyl groups can effectively improve the selectivity in the hydrogenation catalytic reaction because the introduction of hydroxyl groups makes hydrogen atoms stay on the olefin double bond for free radical addition, enabling the hydrogenation reaction to occur on the carbon-carbon double bond rather than on the benzene ring.

[0012] Furthermore, the preparation method of the palladium-nickel resin-type hydrogenation catalyst is as follows:

[0013] S1. Add hydrochloric acid dropwise to deionized water to obtain dilute hydrochloric acid. Place the soluble palladium salt in the dilute hydrochloric acid and heat it to dissolve to obtain a mixed solution. Then weigh the nickel salt and add it to the mixed solution, stir to dissolve, and prepare a solution with a palladium mass concentration of 3 - 6 wt% and a nickel mass concentration of 3 - 10 wt%.

[0014] S2. Put the dried resin into a container, and then dropwise add the solution prepared in step S1 into the container and continuously stir and impregnate for ion exchange adsorption. After the adsorption is completed, a catalyst precursor is obtained.

[0015] S3. Cool the catalyst precursor prepared in step S2 to room temperature, dry it at 105 °C, put it into a reduction furnace, introduce nitrogen for calcination and carbonization, and then place it in the reduction furnace and introduce hydrogen for reduction at the calcination temperature to obtain a palladium-nickel resin-type hydrogenation catalyst.

[0016] Furthermore, the calcination temperature is 400 °C.

[0017] The ion exchange process of the present invention using the impregnation method is simple, easy to implement and economical. The ion exchange adsorption of the palladium-nickel catalyst is carried out by stirring. The advantage is that it can enhance the migration and diffusion of particles inside the solution, significantly improve the impregnation rate, shorten the impregnation completion time, and finally the granular resin carrier is uniformly impregnated, so that the active components are evenly distributed on the surface of the carrier.

[0018] Furthermore, the soluble palladium salt is palladium chloride.

[0019] Furthermore, the nickel salt is any one of nitrate, acetate, hydrochloride or sulfate.

[0020] In the preparation process of the carrier of the present invention, precious metal palladium and metal nickel salt solution are used, and the catalyst is prepared by the ion exchange method. The production process is simple, the operability is strong, and the hydrogenation result is better. In addition, the use of precious metal palladium and gold-nickel series catalysts also has the advantage of convenient recovery. After use, the catalyst only needs to be placed in a muffle furnace for high-temperature calcination to burn off the carrier resin, so that palladium oxide and nickel oxide can be obtained again.

[0021] At the same time, the present invention uses the ion exchange method, which helps to better design the structure of the catalyst during the preparation of the catalyst. While increasing the strength of the carrier, certain pores can be generated through calcination decomposition, effectively reducing the agglomeration of particles, further improving the pore volume and pore diameter of the carrier, making the surface of the catalyst without obvious accumulation phenomenon, and the specific surface area of the formed catalyst is relatively large.

[0022] It is worth emphasizing that, on the one hand, through the ion exchange method of the present invention, the dispersion degree of the active phase on the surface of the carrier is improved, so that the active components palladium and the promoter nickel are more evenly dispersed, and there are more active sites, enhancing the hydrogenation activity of the catalyst and having a better catalytic effect in the hydrogenation of elastomer SBS. On the other hand, through Figure 2 XRD characterization shows that the crystal structure of the palladium-nickel catalyst can be changed, the adsorption capacity of the carrier can be increased, the catalyst activity and hydrogen selectivity can be improved, which is helpful for the hydrogenation reaction of SBS elastomer and improving the hydrogenation selectivity.

[0023] Furthermore, Figure 3 It can be seen from the adsorption-desorption curve that the BET specific surface area of the catalyst precursor is 5-15 m 2 / g, and the pore volume is 0.01-0.05 cm 2 / g.

[0024] Further, a method for preparing hydrogenated styrene-butadiene-styrene block polymer by using palladium-nickel carbonized resin as catalyst is provided as follows: Dissolve SBS in an organic solvent to form a glue solution, then place it in a reaction vessel, add palladium-nickel carbonized resin hydrogenation catalyst, the reaction temperature is 150-190 °C, the reaction pressure is 2-6 MPa, and react for 5-8 h; After the reaction, centrifuge the reaction solution, and the supernatant is obtained as the hydrogenated product after rotary evaporation.

[0025] Further, the specific process conditions are: temperature 150-190 °C, time: 5-8 h, pressure 2-6 MPa, rotation speed 400 rmp.

[0026] Further, the molar ratio in the elastomer SBS is: PS / PB = 3 / 7.

[0027] Further, the organic solvent is one or a mixture of several of n-heptane, n-octane, cyclohexane, dichloromethane or chloroform.

[0028] In summary, the present invention has the following beneficial effects:

[0029] The preparation process of the present invention follows the tenet of green chemistry. Using heterogeneous catalyst to prepare high-hydrogenation-degree and high-selectivity SEBS solves the problems in the process of preparing SEBS with traditional homogeneous catalyst, such as poor catalyst selectivity, difficult separation, short life, difficult product treatment and complex process. At the same time, the reaction process for preparing the catalyst of the present invention is simple, the product is easy to separate, with high purity and high yield, greatly reducing the difficulty and cost of preparing high-hydrogenation-degree SEBS. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is the infrared spectrum of the catalyst in Example 1 of the present invention;

[0031] Figure 2 is the XRD pattern of the catalyst in Example 1 of the present invention;

[0032] Figure 3 is the adsorption-desorption diagram of the catalyst in Example 1 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0033] To further illustrate the technical means and effects adopted by the present invention to achieve the intended invention purpose, a method for preparing hydrogenated styrene-butadiene-styrene block polymer by using palladium-nickel carbonized resin as catalyst according to the present invention is described in detail below in terms of its specific implementation manner, features and effects.

[0034] The resin used in this specific implementation manner is macroporous sulfonic acid cation exchange resin with 3.2 (mmol / g) H+, and the source is commercially available.

[0035] Example 1

[0036] (1) Preparation of palladium-nickel carbonized resin hydrogenation catalyst:

[0037] S1. At room temperature, slowly add hydrochloric acid dropwise to 5.4 g of deionized water. Weigh 0.0877 g of PdCl2 (commercially available) and place it in dilute hydrochloric acid, stir to dissolve, and then weigh 0.1640 g of Ni(NO3)2∙6H2O and add it to the mixed solution and stir evenly;

[0038] S2. Slowly drop this solution onto 1 g of resin, soak for 4 h. After adsorption is completed, place it in an oven at 105 °C and dry for 8 h, and wait for cooling;

[0039] S3. Place the dried resin particles in a reduction dish and transfer them to a tubular reduction furnace. Pass in nitrogen, heat up at a rate of 2 °C / min, maintain at 400 °C for 3 h, stop heating, stop passing in nitrogen after the temperature cools down, change to passing in hydrogen and continue to heat up at a rate of 2 °C / min, maintain at 400 °C for 2 h, stop heating, stop ventilating after the temperature cools down, and finally take out and store it sealed. The palladium content in the catalyst composition is 5.0%, and the nickel content is 3%.

[0040] (2) Hydrogenation reaction of styrene-butadiene-styrene block polymer:

[0041] Weigh 1.002 g of SBS elastomer (molar ratio: PS / PB = 3 / 7), and take out 0.101 g of the catalyst prepared in this example. Put 60 mL of cyclohexane and a glass magnetic stirrer into the reaction kettle, start stirring, the rotation speed is 400 rmp, the reaction temperature is 150 °C, the reaction time is 6 h, the reaction pressure is 6 MPa. After the reaction is completed, cool to room temperature, take out the product for treatment, and obtain the hydrogenation degree and selectivity.

[0042] Example 2

[0043] (1) Preparation of palladium-nickel carbonized resin hydrogenation catalyst:

[0044] S1. At room temperature, slowly add hydrochloric acid dropwise to 5.4 g of deionized water. Weigh 0.0863 g of PdCl2 (commercially available) and place it in dilute hydrochloric acid, stir to dissolve, and then weigh 0.3640 g of Ni(NO3)2∙6H2O and add it to the mixed solution and stir evenly;

[0045] S2. Slowly drop this solution onto 1 g of resin, soak for 4 h. After adsorption is completed, place it in an oven at 105 °C and dry for 8 h, and wait for cooling;

[0046] S3. Place the dried resin particles in a reduction dish and transfer them to a tubular reduction furnace. Introduce nitrogen gas, heat up at a rate of 2 °C / min, hold at 400 °C for 3 h, stop heating, stop introducing nitrogen gas after the temperature cools down, then change to introduce hydrogen gas and continue to heat up at a rate of 2 °C / min, hold at 400 °C for 2 h, stop heating, stop ventilating after the temperature cools down, and finally take out and store it sealed. The palladium content in the catalyst composition is 5.0% and the nickel content is 6%.

[0047] (2)Hydrogenation reaction of styrene-butadiene-styrene block polymer:

[0048] Weigh 1.003 g of SBS elastomer (molar ratio: PS / PB = 3 / 7), take out 0.100 g of the catalyst prepared in this example, put 60 mL of cyclohexane and a glass magnetic stirrer into the reaction kettle, start stirring, the rotation speed is 400 rmp, the reaction temperature is 150 °C, the reaction time is 6 h, the reaction pressure is 6 MPa. After the reaction is completed, cool it to room temperature, take out the product for treatment, and obtain the hydrogenation degree and selectivity.

[0049] Example 3

[0050] (1)Preparation of palladium-nickel carbonized resin hydrogenation catalyst:

[0051] S1. At room temperature, slowly add hydrochloric acid to 5.4 g of deionized water. Weigh 0.0872 g of PdCl2 (commercially available) and place it in dilute hydrochloric acid, stir to dissolve, then weigh 0.3680 g of Ni(NO3)2∙6H2O and add it to the mixed solution and stir evenly;

[0052] S2. Slowly add this solution dropwise to 1 g of resin, soak for 4 h. After the adsorption is completed, put it in an oven at 105 °C and dry for 8 h, and wait for it to cool down;

[0053] S3. Place the dried resin particles in a reduction dish and transfer them to a tubular reduction furnace. Introduce nitrogen gas, heat up at a rate of 2 °C / min, hold at 400 °C for 3 h, stop heating, stop introducing nitrogen gas after the temperature cools down, then change to introduce hydrogen gas and continue to heat up at a rate of 2 °C / min, hold at 400 °C for 2 h, stop heating, stop ventilating after the temperature cools down, and finally take out and store it sealed. The palladium content in the catalyst composition is 5.0% and the nickel content is 7%.

[0054] (2)Hydrogenation reaction of styrene-butadiene-styrene block polymer:

[0055] Weigh 1.000 g of SBS elastomer (molar ratio: PS / PB = 3 / 7), and take out 0.101 g of the catalyst prepared in this example. Put 60 mL of cyclohexane and one glass magnetic stirrer into the reaction kettle, start stirring, with a rotation speed of 400 rmp, a reaction temperature of 150 °C, a reaction time of 6 h, and a reaction pressure of 6 MPa. After the reaction is completed, cool to room temperature, take out the product for treatment, and obtain the hydrogenation degree and selectivity.

[0056] Example 4

[0057] (1) Preparation of palladium-nickel carbonized resin hydrogenation catalyst:

[0058] S1. At room temperature, slowly drop hydrochloric acid into 5.4 g of deionized water. Weigh 0.0514 g of PdCl2 (commercially available) and place it in dilute hydrochloric acid, stir to dissolve, and then weigh 0.3270 g of Ni(NO3)2∙6H2O and add it to the mixed solution and stir evenly;

[0059] S2. Slowly drop the solution into 1 g of resin, soak for 4 h. After the adsorption is completed, put it into an oven at 105 °C and dry for 8 h, and wait for cooling;

[0060] S3. Place the dried resin particles in a reduction dish and transfer them to a tubular reduction furnace. Pass in nitrogen, heat up at a rate of 2 °C / min, keep it at 400 °C for 3 h, stop heating, stop passing in nitrogen after the temperature cools down, change to pass in hydrogen and continue to heat up at a rate of 2 °C / min, keep it at 400 °C for 2 h, stop heating, stop ventilation after the temperature cools down, and finally take it out and store it sealed. The palladium content in the catalyst composition is 5.0%, and the nickel content is 6%.

[0061] (2) Hydrogenation reaction of styrene-butadiene-styrene block polymer:

[0062] Weigh 1.000 g of SBS elastomer (molar ratio: PS / PB = 3 / 7), and take out 0.101 g of the catalyst prepared in this example. Put 60 mL of cyclohexane and one glass magnetic stirrer into the reaction kettle, start stirring, with a rotation speed of 400 rmp, a reaction temperature of 150 °C, a reaction time of 6 h, and a reaction pressure of 6 MPa. After the reaction is completed, cool to room temperature, take out the product for treatment, and obtain the hydrogenation degree and selectivity.

[0063] Example 5

[0064] (1) Preparation of nickel carbonized resin hydrogenation catalyst:

[0065] S1. At room temperature, weigh 0.2601 g of Ni(NO3)2∙6H2O and place it in about 5.4 g of water, stir and mix evenly to obtain a solution;

[0066] S2. Slowly drop the solution obtained in the previous step into 1 g of resin, soak for 4 h. After the adsorption is completed, place it in an oven at 105 °C and dry for 8 h, and wait for it to cool down;

[0067] S3. Place the dried resin particles in a reduction dish and transfer them to a tubular reduction furnace. Introduce nitrogen gas, heat up at a rate of 2 °C / min, hold at 400 °C for 3 h, stop heating. After the temperature cools down, stop introducing nitrogen gas, change to introduce hydrogen gas and continue to heat up at a rate of 2 °C / min, hold at 400 °C for 2 h, stop heating. After the temperature cools down, stop ventilating, and finally take it out and store it sealed. The nickel content in the catalyst composition is 5.0%.

[0068] (2) Hydrogenation reaction of styrene-butadiene-styrene block copolymer:

[0069] Weigh 1.000 g of SBS elastomer (molar ratio: PS / PB = 3 / 7), and take out 0.101 g of the catalyst prepared in this example. Put 60 mL of cyclohexane and a glass magnetic stirrer into the reaction kettle, start stirring, the rotation speed is 400 rmp, the reaction temperature is 150 °C, the reaction time is 6 h, the reaction pressure is 6 Mpa. After the reaction is completed, cool it to room temperature, take out the product for treatment, and obtain the hydrogenation degree and selectivity.

[0070] Example 6

[0071] (1) Preparation of palladium-carbonized resin hydrogenation catalyst:

[0072] S1. At room temperature, slowly drop hydrochloric acid into 5.4 g of deionized water. Weigh 0.0843 g of PdCl2 (commercially available) and place it in dilute hydrochloric acid, stir and dissolve to obtain a solution;

[0073] S2. Slowly drop this solution into 1 g of resin, soak for 4 h. After the adsorption is completed, place it in an oven at 105 °C and dry for 8 h, and wait for it to cool down;

[0074] S3. Place the dried resin particles in a reduction dish and transfer them to a tubular reduction furnace. Introduce nitrogen gas, heat up at a rate of 2 °C / min, hold at 400 °C for 3 h, stop heating. After the temperature cools down, stop introducing nitrogen gas, change to introduce hydrogen gas and continue to heat up at a rate of 2 °C / min, hold at 400 °C for 2 h, stop heating. After the temperature cools down, stop ventilating, and finally take it out and store it sealed. The palladium content in the catalyst composition is 5.0%.

[0075] (2) Hydrogenation reaction of styrene-butadiene-styrene block copolymer:

[0076] Weigh 1.001 g of SBS elastomer (molar ratio: PS / PB = 3 / 7), and take out 0.101 g of the catalyst prepared in this example. Put 60 mL of cyclohexane and a glass magnetic stirrer into the reaction kettle, start stirring, with a rotation speed of 400 rmp, a reaction temperature of 150 °C, a reaction time of 6 h, and a reaction pressure of 6 Mpa. After the reaction is completed, cool it to room temperature, take out the product for treatment, and obtain the hydrogenation degree and selectivity.

[0077] Example 7

[0078] (1) Preparation of palladium-nickel carbonized resin hydrogenation catalyst:

[0079] S1. At room temperature, slowly add hydrochloric acid to 5.4 g of deionized water. Weigh 0.1063 g of PdCl2 (commercially available) and place it in dilute hydrochloric acid, stir to dissolve, and then weigh 0.324 g of Ni(NO3)2∙6H2O and add it to the mixed solution;

[0080] S2. Slowly add the solution obtained in step S1 to 1 g of resin, soak for 4 h. After the adsorption is completed, put it in an oven at 105 °C and dry for 8 h, and wait for the temperature to drop;

[0081] S3. Place the dried resin particles in a reduction dish and transfer them to a tubular reduction furnace. Pass in nitrogen, heat up at a rate of 2 °C / min, keep it at 400 °C for 3 h, stop heating, stop passing in nitrogen after the temperature cools down, change to pass in hydrogen and continue to heat up at a rate of 2 °C / min, keep it at 400 °C for 2 h, stop heating, stop ventilating after the temperature cools down, and finally take it out and store it sealed. The palladium content in the catalyst composition is 6.0%, and the nickel content is 6.0%.

[0082] (2) Hydrogenation reaction of styrene-butadiene-styrene block polymer:

[0083] Weigh 1.001 g of SBS elastomer (molar ratio: PS / PB = 3 / 7), and take out 0.101 g of the catalyst prepared in this example. Put 60 mL of cyclohexane and a glass magnetic stirrer into the reaction kettle, start stirring, with a rotation speed of 400 rmp, a reaction temperature of 150 °C, a reaction time of 6 h, and a reaction pressure of 6 Mpa. After the reaction is completed, cool it to room temperature, take out the product for treatment, and obtain the hydrogenation degree and selectivity.

[0084] Example 8

[0085] (1) Preparation of palladium-nickel carbonized resin hydrogenation catalyst:

[0086] The same as Example 2.

[0087] (2) Hydrogenation reaction of styrene-butadiene-styrene block polymer:

[0088] The reaction pressure was changed to 2 MPa, and the rest was the same as in Example 2.

[0089] Example 9

[0090] (1) Preparation of palladium-nickel carbonized resin hydrogenation catalyst:

[0091] The same as in Example 2.

[0092] (2) Hydrogenation reaction of styrene-butadiene-styrene block polymer:

[0093] The reaction pressure was changed to 4 MPa, and the rest was the same as in Example 2.

[0094] Example 10

[0095] (1) Preparation of palladium-nickel carbonized resin hydrogenation catalyst:

[0096] The same as in Example 2.

[0097] (2) Hydrogenation reaction of styrene-butadiene-styrene block polymer:

[0098] The reaction pressure was changed to 5 MPa, and the rest was the same as in Example 2.

[0099] Example 11

[0100] (1) Preparation of palladium-nickel carbonized resin hydrogenation catalyst:

[0101] The same as in Example 2.

[0102] (2) Hydrogenation reaction of styrene-butadiene-styrene block polymer:

[0103] The reaction temperature was changed to 160 °C, and the rest was the same as in Example 2.

[0104] Example 12

[0105] (1) Preparation of palladium-nickel carbonized resin hydrogenation catalyst:

[0106] The same as in Example 2.

[0107] (2) Hydrogenation reaction of styrene-butadiene-styrene block polymer:

[0108] The reaction time was changed to 5 h, and the rest was the same as in Example 2.

[0109] Example 13

[0110] (1) Preparation of palladium-nickel carbonized resin hydrogenation catalyst:

[0111] S1. At room temperature, slowly add hydrochloric acid dropwise to 5.4 g of deionized water. Weigh 0.06771 g of PdCl₂ (commercially available) and place it in the dilute hydrochloric acid, stir to dissolve, then weigh 0.304 g of Ni(NO₃)₂∙6H₂O and add it to the mixed solution and stir evenly.

[0112] S2. Slowly add this solution dropwise to 1 g of resin, soak for 4 h. After the adsorption is completed, place it in an oven at 105 °C and dry for 8 h, and wait for it to cool down.

[0113] S3. Place the dried resin particles in a reduction dish and transfer them to a tubular reduction furnace. Pass in nitrogen, heat up at a rate of 2 °C / min, hold at 400 °C for 3 h, stop heating. After the temperature cools down, stop passing in nitrogen, then change to passing in hydrogen and continue to heat up at a rate of 2 °C / min, hold at 400 °C for 3 h, stop heating. After the temperature cools down, stop ventilating, and finally take it out and store it sealed. The palladium content in the catalyst composition is 4.0% and the nickel content is 6%.

[0114] (2) Hydrogenation reaction of styrene-butadiene-styrene block polymer:

[0115] Weigh 1.000 g of SBS elastomer (molar ratio: PS / PB = 3 / 7), take out 0.100 g of the catalyst prepared in this example, put 60 mL of cyclohexane and a glass magnetic stirrer into the reaction kettle, start stirring, the rotation speed is 400 rmp, the reaction temperature is 150 °C, the reaction time is 8 h, the reaction pressure is 6 MPa. After the reaction is completed, cool to room temperature, take out the product for treatment, and obtain the hydrogenation degree and selectivity.

[0116] Example 14

[0117] (1) Preparation of palladium-nickel carbonized resin hydrogenation catalyst:

[0118] S1. At room temperature, slowly add hydrochloric acid dropwise to 5.4 g of deionized water. Weigh 0.0887 g of PdCl₂ (commercially available) and place it in the dilute hydrochloric acid, stir to dissolve, then weigh 0.5411 g of Ni(NO₃)₂∙6H₂O and add it to the mixed solution and stir evenly.

[0119] S2. Slowly add this solution dropwise to 1 g of resin, soak for 4 h. After the adsorption is completed, place it in an oven at 105 °C and dry for 8 h, and wait for it to cool down.

[0120] S3. Place the dried resin particles in a reduction dish and transfer them to a tubular reduction furnace. Introduce nitrogen gas, heat up at a rate of 2 °C / min, hold at 400 °C for 3 h, stop heating, stop introducing nitrogen gas after the temperature cools down, then change to introduce hydrogen gas and continue to heat up at a rate of 2 °C / min, hold at 400 °C for 3 h, stop heating, stop ventilating after the temperature cools down, and finally take out and store it sealed. The palladium content in the catalyst composition is 5.0% and the nickel content is 10%.

[0121] (2)Hydrogenation reaction of styrene-butadiene-styrene block polymer:

[0122] Weigh 1.001 g of SBS elastomer (molar ratio: PS / PB = 3 / 7), and take out 0.100 g of the catalyst prepared in this example. Put 60 mL of cyclohexane and a glass magnetic stirrer into the reaction kettle, start stirring, the rotation speed is 400 rmp, the reaction temperature is 150 °C, the reaction time is 6 h, the reaction pressure is 6 MPa. After the reaction is completed, cool it to room temperature, take out the product for treatment, and obtain the hydrogenation degree and selectivity.

[0123] Example 15

[0124] (1)Preparation of palladium-nickel carbonized resin hydrogenation catalyst:

[0125] S1. At room temperature, slowly drip hydrochloric acid into 5.4 g of deionized water. Weigh 0.0680 g of PdCl2 (commercially available) and place it in dilute hydrochloric acid, stir to dissolve it, and then weigh 0.2602 g of Ni(NO3)2∙6H2O and add it to the mixed solution and stir evenly;

[0126] S2. Slowly drip this solution onto 1 g of resin, soak for 4 h. After the adsorption is completed, put it into an oven at 105 °C and dry for 8 h, and wait for it to cool down;

[0127] S3. Place the dried resin particles in a reduction dish and transfer them to a tubular reduction furnace. Introduce nitrogen gas, heat up at a rate of 2 °C / min, hold at 400 °C for 3 h, stop heating, stop introducing nitrogen gas after the temperature cools down, then change to introduce hydrogen gas and continue to heat up at a rate of 2 °C / min, hold at 400 °C for 3 h, stop heating, stop ventilating after the temperature cools down, and finally take out and store it sealed. The palladium content in the catalyst composition is 4.0% and the nickel content is 5.0%.

[0128] (2)Hydrogenation reaction of styrene-butadiene-styrene block polymer:

[0129] Weigh 1.001 g of SBS elastomer (molar ratio: PS / PB = 3 / 7), and take out 0.100 g of the catalyst prepared in this example. Put 60 mL of cyclohexane and one glass magnetic stirrer into the reaction kettle, start stirring, the rotation speed is 400 rmp, the reaction temperature is 190 °C, the reaction time is 6 h, the reaction pressure is 6 MPa. After the reaction is completed, cool it to room temperature, take out the product for treatment, and obtain the hydrogenation degree and selectivity.

[0130] Comparative Example 1

[0131] (1) Preparation of palladium-nickel carbonized resin hydrogenation catalyst:

[0132] Same as Example 3.

[0133] (2) Hydrogenation reaction of styrene-butadiene-styrene block polymer:

[0134] The molar ratio of SBS elastomer is PS / PB = 4 / 6, and the others are the same as in Example 3.

[0135] Comparative Example 2

[0136] (1) Preparation of palladium-nickel carbonized resin hydrogenation catalyst:

[0137] Put the dried resin particles in a reduction dish and move them to a tubular reduction furnace. Pass in nitrogen, heat up at a rate of 2 °C / min, keep at 400 °C for 3 h, stop heating. After obtaining the supported carbonized resin, carry out loading with the same loading amount and method as in Example 2. Then put the loaded catalyst in a reduction dish and move it to a tubular reduction furnace. Pass in hydrogen and heat up at a rate of 2 °C / min, keep at 400 °C for 2 h, stop heating, wait for the temperature to cool down and stop ventilation, and finally take it out and store it sealed. The palladium content in the catalyst composition is 5.0%, and the nickel content is 6.0% for comparison with Example 2.

[0138] (2) Hydrogenation reaction of styrene-butadiene-styrene block polymer:

[0139] Same as Example 2.

[0140] Comparative Example 3

[0141] (1) Preparation of palladium-nickel carbonized resin hydrogenation catalyst:

[0142] Replace the resin in Example 2 with dried activated carbon.

[0143] S1. At room temperature, slowly drop hydrochloric acid into 5.4 g of deionized water. Weigh 0.0850 g of PdCl2 (commercially available) and place it in dilute hydrochloric acid, stir to dissolve, and then weigh 0.3518 g of Ni(NO3)2∙6H2O and add it to the mixed solution;

[0144] S2. Slowly add the solution dropwise to 1 g of activated carbon and soak for 4 h. After adsorption is completed, place it in an oven at 105 °C and dry for 8 h, then wait for it to cool down;

[0145] S3. Place the dried activated carbon in a reduction dish and transfer it to a tubular reduction furnace. Pass hydrogen and continue to heat up at a rate of 2 °C / min. Keep it at 400 °C for 2 h, stop heating, wait for the temperature to cool down and then stop passing gas. Finally, take it out and store it sealed. The palladium content in the catalyst composition is 5.0% and the nickel content is 6%.

[0146] (2) Hydrogenation reaction of styrene-butadiene-styrene block polymer:

[0147] Same as Example 2.

[0148] Test results

[0149] Table 1 shows the hydrogenation degree and selectivity of SBS elastomers in Examples 1-15 and Comparative Examples 1-3.

[0150] Table 1. Hydrogenation degree and selectivity of SBS elastomers

[0151]

[0152] From the data comparison in Table 1, the following conclusions can be drawn:

[0153] 1. From the comparison between Example 3 and Comparative Example 1, it can be seen that the catalyst prepared by the present invention is applicable to the hydrogenation of SBS elastomers with a PS / PB molar ratio of 3 / 7;

[0154] 2. From the data comparison between Example 2 and Comparative Example 2, it can be seen that the preparation method of first loading and then calcining and carbonizing provided by the present invention can greatly improve the catalytic effect;

[0155] 3. From the data comparison between Example 2 and Comparative Example 3, it can be seen that although the present invention obtains carbonized resin by calcining resin, and this carbonized resin is similar to activated carbon, the carbonized resin provided by the present invention also contains hydroxyl groups, which can greatly improve the selectivity of hydrogenation.

[0156] 4. The results of Examples 1-7 in the above table show that under the process conditions of a rotation speed of 400 rmp, a reaction temperature of 150 °C, a reaction time of 6 h, and a reaction pressure of 6 MPa, the combined catalyst with a palladium-nickel mass fraction of 5% palladium and 6% nickel has the best activity, hydrogenation degree, and selectivity, that is, the product prepared by the catalyst preparation and process method described in Example 2; in Examples 13-15, by adjusting the mass of palladium-nickel and changing the process conditions: reaction time, reaction temperature, and reaction pressure, SEBS products with a hydrogenation degree and selectivity similar to those of Example 2 are obtained, indicating that the practical applicability of this catalyst is extensive, not limited to a single process condition, and at the same time, it shows high olefin hydrogenation degree and high selectivity of the product. The comparison of the data of using only nickel and only palladium as catalysts in Examples 5 and 6 with that of Example 2 shows that the combined use of palladium-nickel has better hydrogenation degree and selectivity.

[0157] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been shown above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to obtain equivalent embodiments with equivalent changes within the scope of the technical solution of the present invention. However, as long as the content does not depart from the technical solution of the present invention, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing hydrogenated styrene-butadiene-styrene block copolymer by using palladium-nickel carbonized resin as catalyst, which is characterized in that, Using carbonized resin as a carrier, a palladium-nickel resin-type hydrogenation catalyst is prepared by loading a palladium-nickel catalyst. The elastomer SBS is catalytically hydrogenated using this catalyst. The reaction pressure of the catalytic hydrogenation reaction is 5-6 MPa to obtain a hydrogenated styrene-butadiene-styrene block polymer. The catalyst contains hydroxyl groups; the molar ratio in the elastomer SBS is PS / PB = 3 / 7; The carbonized resin is obtained by calcining a macroporous sulfonic acid cation exchange resin with an exchange capacity of 3.2 (mmol / g) H + and the preparation method of the palladium-nickel resin type hydrogenation catalyst is as follows: S1. Add hydrochloric acid dropwise to deionized water to obtain dilute hydrochloric acid. First, weigh a soluble palladium salt and place it in the dilute hydrochloric acid and heat to dissolve to obtain a mixed solution. Then, weigh a nickel salt and add it to the mixed solution, stir to dissolve, and prepare a solution with a palladium mass concentration of 3-6 wt% and a nickel mass concentration of 3-10 wt%; S2. Place the dried resin in a container, and then dropwise add the solution prepared in step S1 to the container and continuously stir and impregnate for ion exchange adsorption. After the adsorption is completed, a catalyst precursor is obtained; S3. Cool the catalyst precursor prepared in step S2 to room temperature, dry it at 105 °C, place it in a reduction furnace, pass in nitrogen for calcination and carbonization, and then place it in the reduction furnace and pass in hydrogen for reduction at the calcination temperature to obtain the palladium-nickel resin-type hydrogenation catalyst.

2. The method for preparing a hydrogenated styrene-butadiene-styrene block polymer by using palladium-nickel carbonized resin as a catalyst according to claim 1, characterized in that, The soluble palladium salt is palladium chloride.

3. A method for preparing a hydrogenated styrene-butadiene-styrene block polymer by using palladium-nickel carbonized resin as a catalyst according to claim 1, characterized in that, The nickel salt is any one of nitrate, acetate, hydrochloride, or sulfate.

4. A method for preparing a hydrogenated styrene-butadiene-styrene block polymer by using palladium-nickel carbonized resin as a catalyst according to claim 1, characterized in that, The BET specific surface area of the catalyst precursor is 5 to 15 m 2 / g, and the pore volume is 0.01 to 0.05 cm 2 / g.

5. A method for preparing a hydrogenated styrene-butadiene-styrene block polymer by using palladium-nickel carbonized resin as a catalyst according to claim 1, characterized in that, The specific operation is as follows: Dissolve SBS in an organic solvent to form a glue solution, then place it in a reaction container, add a palladium-nickel carbonized resin hydrogenation catalyst, the reaction temperature is 150-190 °C, and react for 5-8 h; after the reaction is completed, centrifuge the reaction solution, and the supernatant is obtained as a hydrogenated product after rotary evaporation.

6. A method for preparing a hydrogenated styrene-butadiene-styrene block polymer using palladium-nickel carbonized resin as a catalyst according to claim 5, characterized in that, The organic solvent is one or a mixture of several of n-heptane, n-octane, cyclohexane, dichloromethane, or trichloromethane.

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