A SEBS adhesive, its preparation method, its application, and its apparatus.

Abstract

This invention belongs to the field of thermoplastic elastomer material polymerization and catalytic hydrogenation, specifically relating to an SEBS binder, its preparation method, its application, and its apparatus. After a first-stage polymerization reaction involving a styrene solution, a regulator, and an initiator, a second-stage polymerization reaction is carried out with butadiene in a microchannel reaction unit. A third-stage polymerization reaction is then carried out with styrene in a static mixer 1. The reaction is terminated by end-capping with a capping agent to obtain a capped SBS solution. This capped SBS solution is mixed with a homogeneous catalyst in a static mixer 2 and then introduced into a high-pressure reactor reaction unit for hydrogenation to obtain SEBS. The continuous polymerization technology for preparing SBS in this invention has better mass and heat transfer and higher efficiency than traditional batch reactor polymerization and hydrogenation technologies, and the resulting product has superior quality. It has broad market application and development prospects in the continuous industrial preparation of "green, high-end SEBS".

Description

Technical Field

[0001] This invention belongs to the field of thermoplastic elastomer material polymerization and catalytic hydrogenation, specifically relating to an SEBS binder, its preparation method, its application, and its apparatus. Background Technology

[0002] SEBS is a widely used thermoplastic elastomer with broad applications in footwear, road asphalt modification, liquid sealing materials, adhesives, plastic modification, cables, automotive parts, and medical devices. Currently, no literature or patents report on the use of SEBS as a binder in the preparation of electrodes and electrolyte membranes for all-solid-state lithium-sulfur batteries. SEBS is a saturated form of SBS, synthesized by active anionic polymerization followed by moderate hydrogenation in the presence of a catalyst.

[0003] Regarding anionic polymerization methods for SBS, current domestic literature and patents mainly focus on single-reactor batch polymerization technology. CN118184917A discloses an SBS elastomer and its preparation method and application; CN103374102B discloses a 1,3-conjugated diene / monovinyl aromatic copolymer and its continuous polymerization production method; CN1392166A discloses a method for preparing styrene-based thermoplastic elastomers; and CN105237696A discloses a novel method for synthesizing hydrogenated styrene-butadiene-styrene block copolymers. Existing technologies have the following shortcomings: long reaction time, high exothermic reaction, difficulty in removal, high viscosity leading to low conversion rate, easy deactivation of initiators, and easy formation of gels.

[0004] Regarding homogeneous catalytic hydrogenation modification methods for SEBS, current domestic literature and patents mainly focus on single-reactor batch hydrogenation and continuous hydrogenation technology for unsaturated polymers. Specifically, CN105218768A discloses a method for synthesizing hydrogenated styrene-butadiene-styrene block copolymers, US3696088 discloses a scale-up method for continuous hydrogenation of unsaturated polymers, CN107099008A discloses a method for continuous hydrogenation of polymers containing olefin unsaturated bonds, and CN105085724A discloses a hydrogenation apparatus and method for continuous polymer hydrogenation. Different hydrogenation methods use different reactors, different control methods, and different continuous forms. Existing technologies have the following shortcomings: long hydrogenation reaction time and numerous operation steps; high initial exothermic reaction, difficult to remove, unstable, prone to cross-linking and gel formation, resulting in low reaction efficiency; high energy consumption and complex control technology; large reactor volume, unfavorable for scale-up, and easy polymer decomposition; excessive hydrogenation, easily causing partial catalyst deactivation, etc., affecting application.

[0005] Existing technologies suffer from problems such as long reaction times, complex control techniques, strong exothermic reactions, and difficulty in temperature control. Each preparation method has its own advantages and disadvantages. Therefore, in order to obtain SEBS with suitable molecular weight, narrow distribution, and appropriate structural unit content, a better and more efficient preparation method is needed. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems existing in the prior art and to provide a SEBS adhesive, its preparation method, its application, and its apparatus.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] After the styrene solution undergoes a first-stage polymerization reaction with a regulator and an initiator, it undergoes a second-stage polymerization reaction with butadiene in a microchannel reaction unit, and then undergoes a third-stage polymerization reaction with styrene in a static mixer 1. The reaction is terminated by end-capping with a capping agent to obtain a capped SBS solution. The capped SBS solution is mixed with a homogeneous hydrogenation catalyst in a static mixer 2 and then fed into a high-pressure reactor reaction unit for hydrogenation reaction to obtain SEBS.

[0009] Refined styrene and refined butadiene are obtained by vacuum refining of commercially available styrene and butadiene to remove trace amounts of water, polymerization inhibitors and other impurities.

[0010] Furthermore, after the styrene solution undergoes a first-stage anionic polymerization reaction with a regulator and an initiator in a batch reactor 1, it undergoes a second-stage anionic polymerization reaction with refined butadiene in a microchannel reaction unit, and then undergoes a third-stage polymerization reaction with refined styrene in a static mixer 1. The reaction is terminated by a capping agent in a batch reactor 2 to obtain a capped SBS solution. The capped SBS solution is mixed with a homogeneous hydrogenation catalyst in a static mixer 2 and then introduced into a high-pressure reactor reaction unit for hydrogenation reaction to obtain SEBS.

[0011] The specific preparation steps are as follows:

[0012] (1) Anionic polymerization reaction: Styrene solution, regulator and initiator are carried out in batch reactor 1 for the first stage of anionic polymerization reaction. The resulting polystyrene solution and butadiene are simultaneously fed into the microchannel reaction unit for the second stage of anionic polymerization reaction. The product of the second stage of anionic polymerization reaction is then fed into the static mixer 1 for the third stage of anionic polymerization reaction, to obtain a reactive SBS solution.

[0013] (2) Hydrogen end-capping to terminate the reaction: The reactive SBS solution obtained in step (1) enters the batch reactor 2 and is end-capped by hydrogen to obtain the end-capped SBS solution.

[0014] (3) Homogeneous catalytic hydrogenation reaction: The capped SBS solution obtained in step (2) is mixed with the homogeneous hydrogenation catalyst in static mixer 2 and then introduced into the high-pressure reactor reaction unit to carry out the hydrogenation reaction to obtain the product SEBS.

[0015] In step (1), the styrene solution is obtained by dissolving styrene in a solvent; the solvent is one or more of alkanes, cycloalkanes and aromatics; the molar volume ratio of styrene to solvent is (0.2-0.5):(2-3).

[0016] The initiator is one or more of n-butyllithium, sec-butyllithium, tert-butyllithium and isobutyllithium;

[0017] The regulator is one or more of tetrahydrofuran, diethylene glycol dimethyl ether, tetramethylethylenediamine, and bis(tetrahydrofuran)propane;

[0018] Step (3) The homogeneous hydrogenation catalyst consists of a main catalyst and a co-catalyst; the main catalyst is one of nickel isooctanoate, nickel naphthenate or cobalt naphthenate, and the co-catalyst is triisobutylaluminum. The molar ratio of the main catalyst to the co-catalyst is 1:(1~10).

[0019] In step (1): the batch reactor 1 is jacketed under an external circulating water bath at 35℃~60℃; the reaction time is 20~35min;

[0020] The microchannel reaction unit was placed in a water bath at 55℃~80℃; the reaction time was 15~40min.

[0021] Static mixer 1 is placed in a water bath at 55℃~80℃; the reaction time is 15~30min.

[0022] In step (2): the batch reactor 2 is jacketed under an external circulating water bath at 50℃~70℃; the reaction time is 10~20min;

[0023] In step (3): Static mixer 2 is placed in a water bath at 55℃~70℃; the mixing time is 3-5 minutes;

[0024] The high-pressure reactor reaction unit is jacketed under an external circulating water bath at 60℃~80℃; the reaction time is 30~90min.

[0025] In step (1), the molar ratio of styrene: regulator: initiator in the first stage of anionic polymerization is (0.2-0.5):(0.0002-0.05):(0.001-0.006), preferably, the molar ratio of styrene: regulator: initiator is (0.2-0.5):(0.01-0.05):(0.001-0.006); the molar ratio of styrene in the first stage of anionic polymerization to butadiene in the second stage of anionic polymerization to styrene in the third stage of anionic polymerization is 1:(7-10):1;

[0026] In step (2), the hydrogen pressure is 0.40–0.90 MPa;

[0027] In step (3), the catalyst addition amount is 0.5-5 mmol (Ni or Co) / 100g SBS; hydrogen is introduced from the bottom of the autoclave 3, the hydrogen flow rate is 0.8-2.4 L / h, and the hydrogen pressure is 1.60-3.00 MPa.

[0028] The SBS prepared in step (1) has a molecular weight (Mn) of 100,000 to 330,000; a molecular weight distribution of 1.01 to 1.20; a St (styrene) content of 26.0 to 35.0 wt%; a Bd (butadiene) content of 65.0 to 74.0 wt%, of which the content of 1,2-Bd (butadiene) structural units is 34.0 to 44.0 wt%, and the content of 1,4-Bd (butadiene) structural units is 56.0 to 66.0 wt%.

[0029] The degree of hydrogenation of the SEBS obtained in step (3) is 99.5% to 100%.

[0030] An SEBS adhesive prepared according to the preparation method described above.

[0031] Application of SEBS binder in the preparation of electrodes and electrolyte membranes for all-solid-state lithium-sulfur batteries.

[0032] The continuous process apparatus used in the preparation method includes a batch reactor 1, a microchannel reaction unit, a static mixer 1, a batch reactor 2, a static mixer 2, a high-pressure reactor unit, and a buffer tank 1 connected in sequence.

[0033] The microchannel reaction unit is composed of a microchannel polymerization reactor 1 and a time-delay tube reactor 1 connected in series; the autoclave reaction unit is composed of autoclave 1, autoclave 2 and autoclave 3 connected in series.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] This invention proposes a series combination of a batch reactor, a microchannel polymerization reactor, a delayed-release reactor, and a static mixer to synthesize SBS via active anionic polymerization. SEBS is then prepared through continuous hydrogenation in three batches to serve as a binder for electrodes and electrolyte membranes in all-solid-state lithium-sulfur batteries. High-performance SEBS is obtained by polymerization and hydrogenation of styrene and butadiene monomers using different initiators, regulators, and catalysts, achieving a hydrogenation degree of 99.5%–100%. As a binder, SEBS is used in a slurry coating process to prepare a solid electrolyte membrane with high ionic conductivity, forming a tightly bonded and well-mixed system that is flexible and has a low swelling rate, meeting current binder development needs. This continuous polymerization technology for SBS preparation demonstrates better mass and heat transfer and higher efficiency than traditional batch polymerization and hydrogenation techniques, resulting in superior product quality. It has broad market application and development prospects in the industrial continuous preparation of "green, high-end SEBS."

[0036] This invention addresses the problems of strong exothermic reaction, slow and difficult removal, temperature control difficulties, and long reaction time in the initial stage of anionic reactions of low molecular weight polymers at the microchannel scale. It enables full contact between polystyrene solution and refined butadiene at the microchannel scale. In the three-reactor continuous hydrogenation process, it solves the problems of strong exothermic reaction, temperature control difficulties, and easy polymer cross-linking in the initial stage of single-reactor hydrogenation reaction. Under the action of hydrogen environment, the homogeneous catalyst can react gently with SBS solution, which significantly improves reaction efficiency and process product quality, achieves continuous operation, and allows for designable molecular weight and degree of hydrogenation. Attached Figure Description

[0037] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0038] The following examples further illustrate specific embodiments of the present invention. It should be noted that the specific embodiments described herein are merely for illustrative and explanatory purposes and are not intended to limit the scope of the invention. Furthermore, all raw materials mentioned below, unless otherwise specified, are commercially available products; all process steps or preparation methods not mentioned in detail are process steps or preparation methods known to those skilled in the art.

[0039] The batch reactor 1 of this invention is an anchor batch reactor; the batch reactor 2 is a self-priming propulsion batch reactor; the microchannel polymerization reactor 1 is a collision flow reactor; the delay tube reactor 1 is a coil tube reactor; the high pressure vessel 1 and high pressure vessel 2 are the same as self-priming propulsion high pressure vessel reactors; the high pressure vessel 3 is a plug flow high pressure vessel reactor. All the reaction devices of this invention are commercially available.

[0040] Refined styrene and refined butadiene are obtained by vacuum refining of commercially available styrene and butadiene to remove trace amounts of water, polymerization inhibitors and other impurities.

[0041] Example 1

[0042] (1) Add 46.2g of refined styrene, 1718.0g of cyclohexane (1030.8g), and benzene (687.2g) in a mixed solvent (mixing ratio of 6:4) to batch reactor 1. Add 3.7mL of tetrahydrofuran and 1.4mL of tetramethylethylenediamine (a 5% cyclohexane solution) to batch reactor 1. 1.8 mL of 1.3 M sec-butyllithium (sec-butyllithium hexane solution) initiator was added to batch reactor 1 to initiate the polymerization reaction. Batch reactor 1 was jacketed under a 40°C external circulating water bath, and the polymerization reaction proceeded for 25 min to obtain a polystyrene solution. Using metering pumps and micro-metering pumps, the polystyrene solution and 213.2 g of refined butadiene were metered into the microchannel polymerization reactor 1 and the delayed-tube reactor 1, which were connected in series, in two separate streams for the reaction. Microchannel polymerization reactor 1 and delayed-tube reactor 1 were placed in a 72°C water bath. Utilizing the efficient mixing, mass transfer, and heat transfer characteristics of the microchannels, a second-stage anionic polymerization reaction was carried out in microchannel polymerization reactor 1 and delayed-tube reactor 1. The residence time of the solution in the microchannel reaction unit was 24 min. 0 min; Using a micro-metering pump, 44.7 g of refined styrene was mixed with the solution generated by the microchannel reaction unit at the end of the delayed-action tube reactor 1 and then introduced into the static mixer 1 for the third-stage anionic polymerization reaction. The static mixer 1 was placed in a 72°C water bath, and the residence time of the solution in the static mixer 1 was 27.0 min, resulting in a 14.9 wt% reactive SBS solution (styrene content of 29.9 wt%, butadiene content of 70.1 wt%; of which the butadiene contained 39.2 wt% 1,2-structural units and 60.8 wt% 1,4-structural units), with a solution viscosity of 1255 cps, a molecular weight of 236063, and a distribution of 1.07; the product was then introduced into the batch reactor 2.

[0043] (2) The SBS solution in the batch reactor 2 was subjected to a sealing and termination reaction under low-pressure hydrogen gas at 0.6 MPa. The batch reactor 2 was jacketed under an external circulating water bath at 60°C, and the sealing and termination reaction was carried out for 15 min.

[0044] (3) The capped SBS solution and nickel-based catalyst (nickel naphthenate and triisobutylaluminum molar ratio of 1:3) (catalyst addition amount of 0.16gNi / 100gSBS) were metered by a metering pump and a micro-metering pump in two separate streams and mixed in a static mixer 2 before entering a reactor consisting of a series of high-pressure reactors 1, 2, and 3 for hydrogenation reaction. The static mixer 2 was placed in a 60℃ water bath, and the residence time of the solution in the static mixer 2 was 3min. The high-pressure reactors 1, 2, and 3 were jacketed in a 70℃ external circulating water bath, and the total residence time in the high-pressure reactor reaction unit was 41min. Hydrogen gas was introduced from the bottom of the high-pressure reactor 3 at a flow rate of 1.2L / h and a hydrogen pressure of 1.90MPa. The product entered a buffer tank 1, and then underwent oxidation with 8wt% hydrogen peroxide solution, citric acid washing (citric acid can be replaced with sebacic acid or adipic acid), centrifugal desalting, alkali washing, centrifugal dehydration, wet coagulation, and drying to obtain 183.2g of hydrogenated product. 1 H-NMR analysis (based on the spectrum) showed 99.7% purity of the SEBS dry gel.

[0045] Example 2

[0046] (1) Add 45.7g of refined styrene and 1744.0g of cyclohexane to batch reactor 1. Add 3.1mL of tetrahydrofuran and 2.3mL of tetramethylethylenediamine (a 5% cyclohexane solution) to batch reactor 1. 2.0 mL of 1.6 M n-butyllithium (n-butyllithium hexane solution) initiator was added to batch reactor 1 to initiate the polymerization reaction. Batch reactor 1 was jacketed under a 45°C external circulating water bath. The polymerization reaction proceeded for 22 min to obtain a polystyrene solution. Using metering pumps and micro-metering pumps, the polystyrene solution and 210.5 g of refined butadiene were metered into a microchannel reaction unit consisting of microchannel polymerization reactor 1 and a time-delayed tube reactor 1 connected in series. Microchannel polymerization reactor 1 and time-delayed tube reactor 1 were placed in a 75°C water bath. Utilizing the efficient mixing, mass transfer, and heat transfer characteristics of the microchannels, a second-stage anionic polymerization reaction was carried out in microchannel polymerization reactor 1 and time-delayed tube reactor 1. The residence time of the solution in the microchannel reaction unit was 21 min. 0.5 min; Using a micro-metering pump, 45.0 g of refined styrene was mixed with the solution generated by the microchannel reaction unit at the end of the delayed-action tube reactor 1 and then introduced into the static mixer 1 for the third-stage anionic polymerization reaction. The static mixer 1 was placed in a 75°C water bath, and the residence time of the solution in the static mixer 1 was 23.5 min, resulting in a 14.6 wt% reactive SBS solution (styrene content 30.1 wt%, butadiene content 69.9 wt%; of which the butadiene contained 41.8 wt% 1,2-structural units and 58.2 wt% 1,4-structural units), with a solution viscosity of 1060 cps, a molecular weight of 174530, and a distribution of 1.09; the product was then introduced into the batch reactor 2.

[0047] Steps (2) and (3) are the same as steps (2) and (3) in Example 1, yielding 210.0 g of hydrogenation degree ( 1 (Based on H-NMR analysis and spectral calculations) 99.5% SEBS dry gel.

[0048] Example 3

[0049] (1) Add 45.0g of refined styrene, 1720.0g of cyclohexane (1032.0g) and hexane (688.0g) mixed solvent (mixing ratio of 6:4) to batch reactor 1. Add 3.5mL of bis(tetrahydrofurfuryl) (5% cyclohexane solution) to batch reactor 1. 3.6 mL of 1.6 M n-butyllithium (n-butyllithium hexane solution) initiator was added to batch reactor 1 to initiate the polymerization reaction. Batch reactor 1 was jacketed under a 45°C external circulating water bath, and the polymerization reaction proceeded for 20 min to obtain a polystyrene solution. Using metering pumps and micro-metering pumps, the polystyrene solution and 212.6 g of refined butadiene were metered into the microchannel polymerization reactor 1 and the delayed-tube reactor 1, which were connected in series, in two separate streams for the reaction. Microchannel polymerization reactor 1 and delayed-tube reactor 1 were placed in a 70°C water bath. Utilizing the efficient mixing, mass transfer, and heat transfer characteristics of the microchannels, a second-stage anionic polymerization reaction was carried out in microchannel polymerization reactor 1 and delayed-tube reactor 1. The residence time of the solution in the microchannel reaction unit was 17 minutes. 0.5 min; Using a micro-metering pump, 47.2 g of refined styrene was mixed with the solution generated by the microchannel reaction unit at the end of the delayed-action tube reactor 1 and then introduced into the static mixer 1 for the third-stage anionic polymerization reaction. The static mixer 1 was placed in a 70°C water bath, and the residence time of the solution in the static mixer 1 was 18.5 min, resulting in a 15.04 wt% reactive SBS solution (styrene content 30.2 wt%, butadiene content 69.8 wt%; of which the butadiene contained 39.7 wt% 1,2-structural units and 60.3 wt% 1,4-structural units), with a solution viscosity of 750 cps, a molecular weight of 110530, and a distribution of 1.04; the product was then introduced into the batch reactor 2.

[0050] Steps (2) and (3) are the same as steps (2) and (3) in Example 1, yielding 225.3g of hydrogenation degree ( 1 (Based on H-NMR analysis and spectral calculations) 99.9% SEBS dry gel.

[0051] Example 4

[0052] (1) Add 43.2g of refined styrene, 1704.0g of cyclohexane (852.0g) and benzene (852.0g) mixed solvent (mixing ratio of 5:5) to batch reactor 1. Add 2.9mL of tetrahydrofuran to batch reactor 1. 1.4 mL of 1.3 M sec-butyllithium (sec-butyllithium hexane solution) initiator was added to batch reactor 1 to initiate the polymerization reaction. Batch reactor 1 was jacketed under a 45°C external circulating water bath. The polymerization reaction proceeded for 27.5 min to obtain a polystyrene solution. Using metering pumps and micro-metering pumps, the polystyrene solution and 208.7 g of refined butadiene were metered into the microchannel reaction unit, which consisted of microchannel polymerization reactor 1 and a time-delayed tube reactor 1 connected in series, in two separate streams. Microchannel polymerization reactor 1 and time-delayed tube reactor 1 were placed in an 80°C water bath. Utilizing the efficient mixing, mass transfer, and heat transfer characteristics of the microchannels, a second-stage anionic polymerization reaction was carried out in microchannel polymerization reactor 1 and time-delayed tube reactor 1. The residence time of the solution in the microchannel reaction unit was 2 minutes. 8.0 min; Using a micro-metering pump, 45.9 g of refined styrene was mixed with the solution generated by the microchannel reaction unit at the end of the delayed-action tube reactor 1 and then introduced into the static mixer 1 for the third-stage anionic polymerization reaction. The static mixer 1 was placed in an 80°C water bath, and the residence time of the solution in the static mixer 1 was 27.5 min, resulting in a 14.8 wt% reactive SBS solution (styrene content of 29.8 wt%, butadiene content of 70.2 wt%; of which the butadiene contained 34.4 wt% 1,2-structural units and 65.6 wt% 1,4-structural units), with a solution viscosity of 2830 cps, a molecular weight of 294033, and a distribution of 1.10; the product was then introduced into the batch reactor 2.

[0053] (2) The SBS solution in the batch reactor 2 was subjected to a capping and termination reaction under low-pressure hydrogen gas at 0.7 MPa. The batch reactor 2 was jacketed under an external circulating water bath at 65°C, and the capping and termination reaction was carried out for 18 min.

[0054] (3) The capped SBS solution and nickel-based catalyst (nickel isooctanoate to triisobutylaluminum molar ratio of 1:2.5) (catalyst addition amount of 0.20gNi / 100gSBS) were metered by a metering pump and a micro-metering pump in two separate streams and mixed in a static mixer 2 before entering a reactor consisting of a series of high-pressure reactors 1, 2, and 3 for hydrogenation reaction. The static mixer 2 was placed in a 60℃ water bath, and the residence time of the solution in the static mixer 2 was 3min. High-pressure reactors 1, 2, and 3 were jacketed in a 75℃ external circulating water bath, and the total residence time in the high-pressure reactor reaction unit was 50min. Hydrogen gas was introduced from the bottom of high-pressure reactor 3 at a flow rate of 1.5L / h and a pressure of 2.30MPa. The product entered a buffer tank 1, and then underwent oxidation with 8wt% hydrogen peroxide solution, citric acid washing, centrifugal desalting, alkali washing, centrifugal dehydration, wet coagulation, and drying to obtain 169.4g of hydrogenated product. 1 100.0% SEBS dry gel (based on 1H-NMR analysis and spectral calculations).

[0055] Example 5

[0056] (1) Add 46.9g of refined styrene and 1754.0g of cyclohexane to batch reactor 1. Add 3.7mL of tetrahydrofuran and 1.5mL of diethylene glycol dimethyl ether (5% cyclohexane solution) to batch reactor 1. 1.8 mL of 1.3 M sec-butyllithium (sec-butyllithium hexane solution) initiator was added to batch reactor 1 to initiate the polymerization reaction. Batch reactor 1 was jacketed under a 40°C external circulating water bath, and the polymerization reaction proceeded for 25 min to obtain a polystyrene solution. Using metering pumps and micro-metering pumps, the polystyrene solution and 206.4 g of refined butadiene were metered into the microchannel polymerization reactor 1 and the delayed-tube reactor 1, which were connected in series, in two separate streams for the reaction. Microchannel polymerization reactor 1 and delayed-tube reactor 1 were placed in a 70°C water bath. Utilizing the efficient mixing, mass transfer, and heat transfer characteristics of the microchannels, a second-stage anionic polymerization reaction was carried out in microchannel polymerization reactor 1 and delayed-tube reactor 1. The residence time of the solution in the microchannel reaction unit was 25 min. 0.5 min; Using a micro-metering pump, 43.0 g of refined styrene was mixed with the solution generated by the microchannel reaction unit at the end of the delayed-action tube reactor 1 and then introduced into the static mixer 1 for the third-stage anionic polymerization reaction. The static mixer 1 was placed in a 70°C water bath, and the residence time of the solution in the static mixer 1 was 25.0 min, resulting in a 14.4 wt% reactive SBS solution (styrene content 30.2 wt%, butadiene content 69.8 wt%; of which the butadiene contained 42.1 wt% 1,2-structural units and 57.9 wt% 1,4-structural units), with a solution viscosity of 1543 cps, a molecular weight of 254908, and a distribution of 1.08; the product was then introduced into the batch reactor 2.

[0057] Steps (2) and (3) are the same as steps (2) and (3) in Example 1, yielding 190.9g of hydrogenation degree ( 1 (Based on H-NMR analysis and spectral calculations) 99.9% SEBS dry gel.

[0058] Example 6

[0059] (1) Add 33.2g of refined styrene, 1832.0g of cyclohexane (916.0g) and benzene (916.0g) mixed solvent (mixing ratio of 5:4) to batch reactor 1. Add 2.4mL of tetrahydrofuran and 1.5mL of tetramethylethylenediamine (5% cyclohexane solution) to batch reactor 1. 1.2 mL of 1.3 M sec-butyllithium (sec-butyllithium hexane solution) initiator was added to batch reactor 1 to initiate the polymerization reaction. Batch reactor 1 was jacketed under a 40°C external circulating water bath. The polymerization reaction proceeded for 20 min to obtain a polystyrene solution. Using metering pumps and micro-metering pumps, the polystyrene solution and 136.5 g of refined butadiene were metered into the microchannel polymerization reactor 1 and the delayed-time tube reactor 1, forming a microchannel reaction unit connected in series. The microchannel polymerization reactor 1 and the delayed-time tube reactor 1 were placed in a 70°C water bath. Utilizing the efficient mixing, mass transfer, and heat transfer characteristics of the microchannels, a second-stage anionic polymerization reaction was carried out in the microchannel polymerization reactor 1 and the delayed-time tube reactor 1. The residence time of the solution in the microchannel reaction unit was 1 minute. 8.0 min; Using a micro-metering pump, 32.0 g of refined styrene was mixed with the solution generated by the microchannel reaction unit at the end of the delayed-action tube reactor 1 and then introduced into the static mixer 1 for the third-stage anionic polymerization reaction. The static mixer 1 was placed in a 70°C water bath, and the residence time of the solution in the static mixer 1 was 16.5 min, resulting in a 9.8 wt% reactive SBS solution (styrene content of 32.2 wt%, butadiene content of 67.8 wt%; of which the butadiene contained 43.6 wt% 1,2-structural units and 56.4 wt% 1,4-structural units), with a solution viscosity of 302 cps, a molecular weight of 218054, and a distribution of 1.05; the product was then introduced into the batch reactor 2.

[0060] (2) Step (2) is the same as step (2) in Example 1.

[0061] (3) The capped SBS solution and cobalt-based catalyst (cobalt naphthenate to triisobutylaluminum molar ratio of 1:1.2) (catalyst addition amount of 0.08gCo / 100gSBS) were metered by a metering pump and a micro-metering pump in two separate streams and mixed in a static mixer 2 before entering a reactor consisting of high-pressure reactors 1, 2, and 3 connected in series for hydrogenation reaction. The static mixer 2 was placed in a 60℃ water bath, and the residence time of the solution in the static mixer 2 was 3min. High-pressure reactors 1, 2, and 3 were jacketed in a 70℃ external circulating water bath, and the total residence time in the high-pressure reactor reaction unit was 34.5min. Hydrogen gas was introduced from the bottom of high-pressure reactor 3 at a flow rate of 0.9L / h and a pressure of 2.50MPa. The product entered a buffer tank 1, and then underwent oxidation with 8wt% hydrogen peroxide solution, citric acid washing, centrifugal desalting, alkali washing, centrifugal dehydration, wet coagulation, and drying to obtain 138.9g of hydrogenated product. 1 H-NMR analysis (based on the spectrum) showed 99.7% purity of the SEBS dry gel.

[0062] Comparative Example 1

[0063] The difference between Comparative Example 1 and Example 1 is that all anionic polymerization steps and hydrogen-terminated termination steps in Example 1 were performed in the same conventional polymerization reactor, and all homogeneous catalytic hydrogenation steps were performed in a conventional high-pressure hydrogenation reactor; the total time for anionic polymerization was 150 min, the time for hydrogen-terminated termination was 15 min, and the total time for homogeneous catalytic hydrogenation was 120 min; the anionic polymerization yielded a 15.0 wt% reactive SBS solution (styrene content 30.1 wt%, butadiene content 69.9 wt%; of which the butadiene contained 38.7 wt% 1,2-structural units and 61.3 wt% 1,4-structural units), with a solution viscosity of 1301 cps, a molecular weight of 239940, and a distribution of 1.12; after hydrogenation modification, 190.4 g of hydrogenation degree (…) was obtained. 1 H-NMR analysis (based on the spectrum) showed 98.9% SEBS dry gel purity.

[0064] Comparative Example 2

[0065] The steps of the anionic polymerization reaction and the hydrogen end-capping termination reaction were the same as in Example 6. The difference between Comparative Example 2 and Example 6 was that the anionic polymerization reaction yielded a 9.8 wt% reactive SBS solution (styrene content 31.9 wt%, butadiene content 68.1 wt%; of which the butadiene contained 43.0 wt% 1,2-structural units and 57.0 wt% 1,4-structural units), with a solution viscosity of 289 cps, a molecular weight of 214664, and a distribution of 1.05. During the hydrogenation modification reaction, autoclaves 1, 2, and 3 were jacketed under a 40°C external circulating water bath, yielding a hydrogenation degree of 145.9 g (…). 1 H-NMR analysis (based on the spectrum) showed 84.1% SEBS dry gel.

[0066] Comparative Example 3

[0067] The steps of the anionic polymerization reaction and the hydrogen end-capping termination reaction were the same as in Example 6. The difference between Comparative Example 3 and Example 6 was that the anionic polymerization reaction yielded a 9.8 wt% reactive SBS solution (styrene content 31.9 wt%, butadiene content 68.1 wt%; of which the butadiene contained 43.0 wt% 1,2-structural units and 57.0 wt% 1,4-structural units), with a solution viscosity of 270 cps, a molecular weight of 210058, and a distribution of 1.06; during the hydrogenation modification reaction, the total residence time in the autoclave reaction unit was 20.0 min, yielding 140.6 g of hydrogenation degree (…). 1 H-NMR analysis (based on the spectrum) showed that the dry SEBS gel contained 80.9% of the content.

[0068] Comparative Example 4

[0069] The steps of the anionic polymerization reaction and the hydrogen-terminated end-capping reaction were the same as in Example 1. The difference between Comparative Example 4 and Example 1 was that the feeding ratio of styrene and butadiene was changed. The mass ratio of styrene in the first stage reaction to butadiene in the second stage reaction to styrene in the third stage reaction was 23.0:54.0:23.0. The anionic polymerization reaction yielded a 14.8 wt% reactive SBS solution (styrene content was 45.8 wt%, butadiene content was 54.2 wt%; of which the butadiene contained 41.9 wt% 1,2-structural units and 58.1 wt% 1,4-structural units), with a solution viscosity of 1233 cps, a molecular weight of 231205, and a distribution of 1.08. After hydrogenation modification, 177.9 g of hydrogenated solution was obtained. 1 ¹H-NMR analysis (based on spectral calculations) showed 99.6% purity of the SEBS dry gel. Solid electrolyte membrane preparation and wet processing conditions.

[0070] Preparation conditions and preparation ratio:

[0071] Preparation conditions:

[0072] SEBS powder is dissolved in xylene, toluene, or benzene to prepare a binder system of a certain concentration, and then Li... 10 Si 0.3 PS 6.7 Cl 1.8 (LiSiPSCl) solid electrolyte powder is mixed with the binder system, and xylene, toluene or benzene is added to adjust the viscosity. The mixture is then dispersed and stirred at high speed for 20 to 30 minutes. The slurry is then evenly coated onto a stainless steel test sample and dried at 60℃ to 80℃ for 24 hours to remove the solvent from the system.

[0073] Configuration ratio:

[0074] Solid electrolyte membranes were prepared by slurry coating process using Examples 1-6 and Comparative Examples 1-4 as binders: 100 parts LiSiPSCl; 25 parts benzene; 25 parts xylene; and 3 parts SEBS binder.

[0075] Comparative Example 5: 100 parts LiSiPSCl; 25 parts benzene; 25 parts xylene; 3 parts commercially available nitrile rubber (NBR) adhesive (Ningbo Shunze Rubber Co., Ltd.)

[0076] Comparative Example 6: 100 parts LiSiPSCl; 25 parts benzene; 25 parts xylene; 3 parts commercially available polyvinylidene fluoride (PVDF) adhesive (Shanghai Duoyuan Plastic Raw Materials Co., Ltd.)

[0077] Mechanical and electrochemical performance characterization

[0078] The mechanical properties, constant current charge-discharge test, and AC impedance test of the solid electrolyte membrane are conducted in accordance with relevant national standards and enterprise standards.

[0079] Constant current charge / discharge test: The CT 2001A LAND micro / small current tester was used, and the test voltage range was 0.9 to 2.4V. During the cycle, the discharge was performed first, followed by the charge.

[0080] AC impedance testing: An Autolab PGSTAT302N electrochemical workstation was used. The test conditions were: temperature 25℃, sinusoidal wave amplitude 5mV, and frequency range 10. 6 ~10 -1 Hz.

[0081] The electrochemical performance test results of the solid electrolyte membrane are shown in Table 1.

[0082] Table 1. Electrochemical performance test results of solid electrolyte membranes

[0083]

[0084] As shown in Table 1, under the same addition amount, the solid electrolyte membrane prepared by SEBS as a binder in the embodiments of the present invention has greater adhesion, better flexibility and film-forming properties, higher ionic conductivity, and lower electrolyte swelling rate, thus maximizing the overall performance of the electrolyte membrane. Furthermore, the first discharge specific capacity of the all-solid-state lithium battery assembled with the electrolyte membrane is also higher than that of commercially available similar products. The SEBS binder prepared in Comparative Example 4 has a higher styrene content, indicating greater rigidity, poorer flexibility and film-forming properties, which is detrimental to dispersion and results in uneven distribution, affecting the ionic conductivity after film formation.

[0085] From the overall examples, the SEBS binder with a high number-average molecular weight (large Mn) is more effective than the SEBS binder with a low number-average molecular weight (small Mn); the SEBS binder with a high degree of hydrogenation is more effective than the SEBS binder with a low degree of hydrogenation; at the same time, compared with the commercially available binders added in Comparative Examples 5 and 6, the electrolyte membranes formed by the self-made binders in Examples 1-6 have better adhesion, toughness and ionic conductivity than the solid electrolyte membranes with commercially available binders added.

[0086] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A continuous preparation method for SEBS adhesive, characterized in that: After the styrene solution undergoes a first-stage anionic polymerization reaction with a regulator and an initiator, it undergoes a second-stage anionic polymerization reaction with refined butadiene in a microchannel reaction unit, and then undergoes a third-stage anionic polymerization reaction with refined styrene in a static mixer 1. The reaction is terminated by a capping agent to obtain a capped SBS solution. The capped SBS solution is mixed with a homogeneous hydrogenation catalyst in a static mixer 2 and then fed into a high-pressure reactor reaction unit for hydrogenation reaction to obtain SEBS. The high-pressure reactor reaction unit consists of high-pressure reactor 1, high-pressure reactor 2 and high-pressure reactor 3 connected in series; The high-pressure reactor reaction unit is jacketed under an external circulating water bath at 60℃~80℃; the reaction time is 30~90min. The molar ratio of styrene in the first anionic polymerization reaction to butadiene in the second anionic polymerization reaction to styrene in the third anionic polymerization reaction is 1:(7~10):

1.

2. The continuous preparation method of SEBS adhesive according to claim 1, characterized in that, Includes the following steps: (1) Anionic polymerization reaction: Styrene solution, regulator and initiator are carried out in batch reactor 1 for the first stage of anionic polymerization reaction. The resulting polystyrene solution and refined butadiene are simultaneously fed into the microchannel reaction unit for the second stage of anionic polymerization reaction. The product of the second stage of anionic polymerization reaction is then fed into the static mixer 1 along with refined styrene for the third stage of anionic polymerization reaction to obtain a reactive SBS solution. (2) Hydrogen end-capping to terminate the reaction: The reactive SBS solution obtained in step (1) enters the batch reactor 2 and is end-capped by hydrogen to obtain the end-capped SBS solution. (3) Homogeneous catalytic hydrogenation reaction: The capped SBS solution obtained in step (2) is mixed with the homogeneous hydrogenation catalyst in static mixer 2 and then fed into the high-pressure reactor reaction unit to carry out the hydrogenation reaction to obtain the product SEBS.

3. The continuous preparation method of SEBS adhesive according to claim 2, characterized in that: In step (1), the styrene solution is obtained by dissolving styrene in a solvent; the solvent is one or more of alkanes, cycloalkanes, and aromatics. The initiator is one or more of n-butyllithium, sec-butyllithium, tert-butyllithium and isobutyllithium; The regulator is one or more of tetrahydrofuran, diethylene glycol dimethyl ether, tetramethylethylenediamine, and bis(tetrahydrofuran)propane; Step (3) The homogeneous hydrogenation catalyst consists of a main catalyst and a co-catalyst; the main catalyst is one of nickel isooctanoate, nickel naphthenate or cobalt naphthenate, and the co-catalyst is triisobutylaluminum. The molar ratio of the main catalyst to the co-catalyst is 1: (1~10).

4. The continuous preparation method of SEBS adhesive according to claim 2, characterized in that: In step (1): the batch reactor 1 is jacketed under an external circulating water bath at 35℃~60℃; the reaction time is 20~35min; The microchannel reaction unit was placed in a water bath at 55℃~80℃; the reaction time was 15~40 min. Static mixer 1 is placed in a water bath at 55℃~80℃; the reaction time is 15~30min. In step (2): the batch reactor 2 is jacketed under an external circulating water bath at 50~70℃; the reaction time is 10~20min; In step (3): the static mixer 2 is placed in a water bath at 55℃~70℃; the mixing time is 3-5 min.

5. The continuous preparation method of SEBS adhesive according to claim 2, characterized in that: In step (1), the molar ratio of styrene: regulator: initiator in the first stage of anionic polymerization is (0.2~0.5):(0.0002-0.05):(0.001~0.006). In step (2), the hydrogen pressure is 0.40~0.90 MPa; In step (3), the amount of catalyst added is 0.5~5 mmolNi or Co / 100gSBS; the hydrogen flow rate is 0.8~2.4L / h; and the hydrogen pressure is 1.60~3.00MPa.

6. The continuous preparation method of SEBS adhesive according to claim 5, characterized in that: The SBS prepared in step (1) has a molecular weight (Mn) of 100,000 to 330,000; a molecular weight distribution of 1.01 to 1.20; a styrene content of 26.0 to 35.0% by weight; a butadiene content of 65.0 to 74.0% by weight, of which the content of 1,2-Bd butadiene structural units is 34.0 to 44.0% by weight, and the content of 1,4-Bd butadiene structural units is 56.0 to 66.0% by weight. The degree of hydrogenation of SEBS obtained in step (3) is 99.5%~100%.

7. An SEBS adhesive prepared by the preparation method according to any one of claims 1-6.

8. The application of the SEBS adhesive of claim 7, characterized in that: Application of SEBS binder in the preparation of electrodes and electrolyte membranes for all-solid-state lithium-sulfur batteries.

9. A continuous process apparatus for the preparation method according to claim 1: comprising a batch reactor 1, a microchannel reaction unit, a static mixer 1, a batch reactor 2, a static mixer 2, a high-pressure reactor unit, and a buffer tank 1 connected in sequence.

10. The continuous operation apparatus according to claim 9, characterized in that: The microchannel reaction unit consists of a microchannel polymerization reactor 1 and a time-delay tube reactor 1 connected in series.

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