An acrylate thermoplastic elastomer of the ABABA type, its controllable preparation method and applications

Abstract

The application discloses an ABABA type acrylate thermoplastic elastomer and a controllable preparation method and application thereof. The application belongs to the field of acrylate polymers. The application is to make up for the lack of research on multi-block acrylate elastomers, and to solve the problems that the current synthesis method of tri-block acrylate elastomers needs a long reaction time, the obtained polymer has a wide molecular weight distribution, and complete conversion of monomers cannot be realized. In the application, methyl acrylate is used as the A section, alkyl acrylate is used as the B section, an anionic polymerization method is used, and an amine additive is added to control the controllable polymerization reaction, so that an ABABA type acrylate polymer is finally obtained. The obtained polymer is high-temperature resistant, oil resistant, environmentally friendly, and has excellent mechanical properties, and can be applied to many fields such as aerospace, national defense and military industry, automobile parts, lighting products and plastic modification.

Description

Technical Field

[0001] This invention belongs to the field of acrylate polymers, specifically relating to an ABABA type acrylate thermoplastic elastomer, its controllable preparation method, and its applications. Background Technology

[0002] Thermoplastic elastomers (TPEs) possess the elasticity of rubber at room temperature and can be plasticized and molded at high temperatures, exhibiting the dual properties and characteristics of both rubber and plastics. Styrene-based thermoplastic elastomers, such as styrene-isoprene-styrene (SIS), styrene-butadiene-styrene (SBS), and their hydrides SEPS and SEBS, are most commonly used in plastic modifiers and hot-melt pressure-sensitive adhesives. However, these elastomers have certain drawbacks: the styrene phase has a relatively low temperature gradient (Tg), limiting the material's operating temperature range; and the presence of benzene rings and unsaturated double bonds in the elastomer affects its oxidation resistance and transparency.

[0003] All-acrylate thermoplastic elastomers are triblock copolymers of methacrylate-acrylate-methacrylate, obtained through catalytic polymerization of methacrylate (hard segment) and acrylate (soft segment) monomers. They are among the strategically emerging thermoplastic elastomer materials. The saturated C-H bonds in the molecular backbone provide excellent mechanical properties, transparency, and oxidation resistance, while the polar ester functional groups on the molecular side chains provide excellent oil resistance and sealing properties. Furthermore, the diverse types of acrylate monomers (with different side-chain ester functional groups) give acrylate thermoplastic elastomers a wider glass transition temperature range (-50 to 200°C), and block copolymerization of different monomers can be used to prepare thermoplastic elastomers with different operating temperature ranges. Therefore, all-acrylate thermoplastic elastomers can be applied in many fields such as aerospace, defense, automotive parts, lighting products, and plastic modification.

[0004] Current research on acrylate polymers mainly focuses on diblock and triblock polymerization systems. Furthermore, the synthesis of triblock acrylate elastomers typically employs free radical polymerization, which results in polymers with a wide molecular weight distribution, incomplete monomer conversion, and long reaction times, hindering industrial production. Therefore, finding a simple, efficient, and novel polymerization method to controllably prepare multiblock acrylate polymers is an effective way to develop and broaden the applications of acrylate elastomers in the field of new materials. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an ABABA type acrylate thermoplastic elastomer, its controllable preparation method, and its application.

[0006] One objective of this invention is to provide a controllable preparation method for ABABA type acrylate thermoplastic elastomers, the method comprising the following steps:

[0007] Under anhydrous and oxygen-free conditions, solvents, amine auxiliaries, cocatalysts, initiators, and comonomers are added to a reactor. The comonomers are divided into A-segment and B-segment, and are added sequentially in the order of A-segment, B-segment, A-segment, B-segment, A-segment, and reacted at a certain temperature for a certain time before adding the next monomer. After the polymerization reaction is completed, the monomers are quenched, concentrated, washed, and vacuum dried to obtain ABABA type acrylate thermoplastic elastomers, wherein the monomer in segment A is alkyl methacrylate and the monomer in segment B is alkyl acrylate.

[0008] Further specifying, alkyl methacrylates include, but are not limited to, one or more of methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, n-hexyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, dodecyl methacrylate, tridecyl methacrylate, and stearate methacrylate, with the specific structures shown below:

[0009]

[0010] Further specifying, alkyl acrylates include, but are not limited to, one or more of n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-hexyl acrylate, n-octyl acrylate, and isooctyl acrylate, with the specific structures shown below:

[0011]

[0012] Further specifying, the amine adjuvants include, but are not limited to, one or more of the following: diethylenetriamine, pentamethyldiethylenetriamine, pentamethyldipropylenetriamine, hexamethylphosphoryltriamine, bis(hexamethylene)triamine, ethanolamine, triethylamine, triethanolamine, tripropylamine, ethylenediamine, N,N,N',N'-tetramethylethylenediamine, and N,N'-dimethylformamide, with the specific structures shown below:

[0013]

[0014] Preferably, the amine auxiliaries are one of pentamethyldiethylenetriamine, pentamethyldipropylenetriamine, hexamethylphosphoryltriamine, and N,N,N',N'-tetramethylethylenediamine.

[0015] More preferably, the amine auxiliaries are pentamethyldiethylenetriamine or hexamethylphosphoric triamine.

[0016] Further specifying, the initiator includes, but is not limited to, one or more of the following: n-butyllithium, sec-butyllithium, tert-butyllithium, tert-butoxide lithium, methyllithium, ethyllithium, n-propyllithium, isopropyllithium, phenyllithium, benzyllithium, and naphthyllithium.

[0017] Preferably, the initiator is one of n-butyllithium, sec-butyllithium, and tert-butyllithium.

[0018] More preferably, the initiator is sec-butyllithium.

[0019] Further specifying, the solvent is one or more of the following: amine auxiliaries, benzene, toluene, ethylbenzene, xylene, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and diethoxymethane.

[0020] Preferably, the solvent is toluene or ethylene glycol dimethyl ether.

[0021] Further specified, the co-catalyst is prepared by AlR3 and phenolic reagent in a molar ratio of 1:(1-5).

[0022] Preferably, the co-catalyst is prepared by mixing AlR3 and a phenolic reagent in a molar ratio of 1:2.

[0023] Furthermore, AlR3 is one of triethylaluminum, trimethylaluminum, triisobutylaluminum, diethylaluminum chloride, diethylaluminum chloride, and methylaluminoxane.

[0024] Preferably, AlR3 is triisobutylaluminum or triethylaluminum.

[0025] More preferably, AlR3 is triisobutylaluminum.

[0026] To further specify, the phenolic reagent is one of the arylphenols with different substituents.

[0027] Preferably, the phenolic reagents include, but are not limited to, one of 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-p-methylphenol, 2,6-di-tert-butyl-p-ethylphenol, 2,4,6-tri-tert-butylphenol, 2,6-diisopropylphenol, 2-tert-butylphenol, 2-tert-butyl-5-methylphenol, and 2,6-di-tert-butyl-4-nitrophenol.

[0028] More preferably, the phenolic reagent is 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butyl-p-acetol, or 2,4,6-tri-tert-butylphenol.

[0029] Further optimization reveals that the phenolic reagent is 2,6-di-tert-butyl-p-methylphenol.

[0030] Further, the temperature is limited to -50 to 70°C, and the total polymerization time is 3 to 24 hours.

[0031] Preferably, the temperature is between -30 and 25°C, and the total polymerization time is 10 hours.

[0032] Further specified, the molar ratio of alkyl methacrylate monomer to alkyl acrylate monomer is 1:(1-10), the molar ratio of amine auxiliaries to initiators is 1:(1-150), the molar amount of initiator to the total molar amount of comonomer is 1:(100-5000), and the molar ratio of the total mass of comonomer to the mass of solvent is 1:(0.2-5).

[0033] Preferably, the molar ratio of alkyl methacrylate monomer to alkyl acrylate monomer is 1:(1.5-4), the molar ratio of amine auxiliaries to initiators is 1:(25-100), the molar amount of initiator to the total molar amount of comonomer is 1:(400-800), and the ratio of the total mass of comonomer to the mass of solvent is 1:3.

[0034] Further specified, the vacuum drying temperature is 30–100℃, and the time is 12–36 h;

[0035] Preferably, the vacuum drying temperature is 40°C and the time is 24 hours.

[0036] The second objective of this invention is to provide an ABABA type acrylate thermoplastic elastomer obtained by the above method.

[0037] Further specifying, the number-average molecular weight (M) of the ABABA type acrylate thermoplastic elastomer is... n The molecular weight distribution (PDI) ranges from 10,000 to 500,000 g / mol, and the syndiotactic regularity (rr) of the A-block is 70% to 80%.

[0038] Preferably, the number-average molecular weight (M) of the ABABA type acrylate thermoplastic elastomer is... n The molecular weight distribution (PDI) ranges from 60,000 to 120,000 g / mol, and the syndiotactic regularity (rr) of the A-block is 73% to 78%.

[0039] The third objective of this invention is to provide an application of the ABABA type acrylate thermoplastic elastomer obtained by the above method in the fields of aerospace, defense, automotive parts, lighting products and plastic modification.

[0040] The significant advantages of this invention compared to existing technologies are:

[0041] (1) Compared with traditional methods, the preparation method of the present invention adopts a milder polymerization system and simpler and easier reaction conditions, which is conducive to industrial production.

[0042] (2) The amine auxiliaries used in this invention have advantages such as low toxicity and low price compared with the additives used in traditional methods. They also have good environmental friendliness and can effectively reduce industrialization costs.

[0043] (3) The ABABA type acrylate thermoplastic elastomer prepared by the present invention has a number average molecular weight of 10,000-500,000 g / mol, a molecular weight distribution of 1.1-2.0, and a syndiotactic regularity of rr of PMMA blocks of 70-80%. It has better mechanical properties and excellent heat resistance, oxidation resistance and light transmittance. It can be applied to many fields such as aerospace, national defense, automotive parts, lighting products and plastic modification. Attached Figure Description

[0044] Figure 1 The ABABA type acrylate block polymer of Example 1 1 HNMR spectrum (400MHz, CDCl3, 298K);

[0045] Figure 2 The ABABA type acrylate block polymer of Example 1 13 C10 NMR spectrum (100MHz, CDCl3, 298K);

[0046] Figure 3 The image shows the GPC diagram of the ABABA type acrylate block polymer from Example 1. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0048] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials, reagents, methods, and instruments used are all conventional materials, reagents, methods, and instruments in the art, and can be obtained commercially by those skilled in the art.

[0049] The terms “comprising,” “including,” “having,” “containing,” or any other variations thereof, as used in the following embodiments, are intended to cover a non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such a composition, step, method, article, or apparatus.

[0050] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1 to 5” is disclosed, the described range should be interpreted as including ranges “1 to 4”, “1 to 3”, “1 to 2”, “1 to 2 and 4 to 5”, “1 to 3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range. In this specification and claims, range definitions may be combined and / or interchanged, unless otherwise stated, these ranges include all subranges contained therein.

[0051] The indefinite articles “a” and “an” preceding an element or component of this invention do not impose any limitation on the quantity (i.e., number of times) of the element or component. Therefore, “an” or “a” should be interpreted as including one or at least one, and the singular form of an element or component also includes the plural form, unless the quantity clearly refers only to the singular form.

[0052] Analysis of the regularity of PMMA in the ABABA-type acrylate thermoplastic elastomers described in the following examples (in...) 13 In the C-NMR spectrum, the peaks at 44.5 ppm, 44.8 ppm, and 45.5 ppm all belong to the quaternary carbons of the methyl methacrylate block, and these three peaks represent the stereoregularity of rr, mr, and mm, respectively.

[0053] rr PMMA (%) = [I 44.5 / (I 44.5 +I 44.8+ I 45.5 )]×100%.

[0054] Example 1

[0055] The preparation steps of the ABABA type acrylate thermoplastic elastomer in this embodiment are as follows:

[0056] Under an argon atmosphere, 60 mL of toluene solvent, 2 mL of pentamethyldiethylenetriamine (10 mmol, 25 equiv.), 8.89 mL of i-BuAl(BHT)2 (3.2 mmol, 8 equiv.), 0.3 mL of s-BuLi (0.4 mmol, 1 equiv.), and 1.35 mL of methyl methacrylate monomer (12.5 mmol, 32.5 equiv.) were added sequentially to a 500 mL Schlenk flask. After stirring at 25 °C for one hour, the reaction flask was transferred to a cryogenic reactor, where 8.6 mL of n-butyl acrylate monomer (60 mmol, 150 equiv.) was added. (iv.) After stirring at -30°C for one hour, the reaction flask was removed from the cryogenic reactor and brought to room temperature. Methyl methacrylate monomer (1.35 mL, 12.5 mmol, 32.5 equiv.) was added, and the reaction was stirred again. After stirring at 25°C for three hours, the reaction flask was transferred back to the cryogenic reactor, and n-butyl acrylate (8.6 mL, 60 mmol, 150 equiv.) was added. After stirring at -30°C for one hour, the reaction flask was removed from the cryogenic reactor and brought to room temperature. Methyl methacrylate monomer (1.35 mL, 12.5 mmol, 32.5 equiv.) was added, and the reaction was stirred at 25°C for four hours. The mixture was quenched with methanol and washed three times. The precipitated polymer was dried to constant weight to obtain the ABABA type acrylate block polymer.

[0057] Yield > 99%. NMR characterization showed that the block ratio of methyl methacrylate to n-butyl acrylate was 25:75, which met the designed block ratio, and the interstitial structure ratio (rr) of segment A was 73%. GPC characterization showed that the number-average molecular weight of the product was 67505 g / mol, and the molecular weight distribution was 1.33.

[0058] Table 1. Molecular Weight Information

[0059] Peak1 58447 42276 54386 66402 77495 64717 1.286

[0060] Example 2

[0061] The preparation steps of the ABABA type acrylate thermoplastic elastomer in this embodiment are as follows:

[0062] Under an argon atmosphere, 60 mL of toluene solvent, 1.88 mL of hexamethylphosphoric triamine (10 mmol, 55 equiv.), 3.9 mL of i-BuAl(BHT)2 (1.40 mmol, 8 equiv.), 0.14 mL of s-BuLi (0.18 mmol, 1 equiv.), and 1.01 mL of methyl methacrylate monomer (9.38 mmol, 52 equiv.) were added sequentially to a 500 mL Schlenk flask. After stirring at 25 °C for one hour, the reaction flask was transferred to a cryogenic reactor, where 8.06 mL of n-butyl acrylate monomer (56.25 mmol, 312 mmol) was added. After stirring at -30°C for one hour, the reaction flask was removed from the cryogenic reactor and brought to room temperature. Methyl methacrylate monomer (1.01 mL, 9.38 mmol, 52 equiv.) was added, and the reaction was stirred for another three hours at 25°C. The reaction flask was then transferred to the cryogenic reactor again, and n-butyl acrylate (8.06 mL, 56.25 mmol, 312 equiv.) was added. After stirring at -30°C for one hour, the reaction flask was removed from the cryogenic reactor and brought to room temperature. Methyl methacrylate monomer (1.01 mL, 9.38 mmol, 52 equiv.) was added, and the reaction was stirred for four hours at 25°C. The mixture was quenched with methanol and washed three times. The precipitated polymer was dried to constant weight to obtain the ABABA type acrylate block polymer.

[0063] Yield > 99%. NMR characterization showed that the block ratio of methyl methacrylate to n-butyl acrylate was 2:8, which met the designed block ratio, and the interstitial structure ratio (rr) of segment A was 75%. GPC characterization showed that the number-average molecular weight of the product was 116474 g / mol, and the molecular weight distribution was 1.43.

[0064] Example 3

[0065] The preparation steps of the ABABA type acrylate thermoplastic elastomer in this embodiment are as follows:

[0066] Under an argon atmosphere, 60 mL of toluene solvent, amine auxiliaries N,N,N',N'-tetramethylethylenediamine (2.2 mL, 10 mmol, 55 equiv.), co-catalyst i-BuAl(BHT)2 (3.9 mL, 1.40 mmol, 8 equiv.), initiator s-BuLi (0.14 mL, 0.18 mmol, 1 equiv.), and methyl methacrylate monomer (1.01 mL, 9.38 mmol, 52 equiv.) were added sequentially to a 500 mL Schlenk flask. After stirring at 25 °C for one hour, the reaction flask was transferred to a cryogenic reactor, where n-butyl acrylate monomer (8.06 mL, 56.25 mmol) was added. After stirring at -30°C for one hour, the reaction flask was removed from the cryogenic reactor and brought to room temperature. Methyl methacrylate monomer (1.01 mL, 9.38 mmol, 52 equiv.) was added, and the reaction was stirred again. After stirring at 25°C for three hours, the reaction flask was transferred back to the cryogenic reactor, and n-butyl acrylate (8.06 mL, 56.25 mmol, 312 equiv.) was added. After stirring at -30°C for a certain period, the reaction flask was removed from the cryogenic reactor and brought to room temperature. Methyl methacrylate monomer (1.01 mL, 9.38 mmol, 52 equiv.) was added, and the reaction was stirred at 25°C for four hours. The mixture was quenched with methanol and washed three times. The precipitated polymer was dried to constant weight to obtain the ABABA type acrylate block polymer.

[0067] Yield > 99%. NMR characterization showed that the block ratio of methyl methacrylate to n-butyl acrylate was 2:8, which met the designed block ratio, and the interstitial structure ratio (rr) of segment A was 75%. GPC characterization showed that the number-average molecular weight of the product was 114,150 g / mol, and the molecular weight distribution was 1.55.

[0068] Example 4

[0069] The preparation steps of the ABABA type acrylate thermoplastic elastomer in this embodiment are as follows:

[0070] Under an argon atmosphere, 60 mL of toluene solvent, 2 mL of pentamethyldiethylenetriamine (10 mmol, 55 equiv.), 3.9 mL of i-BuAl(BHT)2 (1.404 mmol, 8 equiv.), 0.14 mL of s-BuLi (0.18 mmol, 1 equiv.), and 1.01 mL of methyl methacrylate (9.375 mmol, 52 equiv.) were added sequentially to a 500 mL Schlenk flask. After stirring at 25 °C for a certain period of time, the reaction flask was transferred to a cryogenic reactor, where 8.06 mL of n-butyl acrylate (56.25 mmol, 31 equiv.) was added. After stirring at -30°C for one hour, the reaction flask was removed from the cryogenic reactor and brought to room temperature. Methyl methacrylate monomer (1.01 mL, 9.38 mmol, 52 equiv.) was added, and the reaction was stirred for another three hours at 25°C. The reaction flask was then transferred back to the cryogenic reactor, and n-butyl acrylate (8.06 mL, 56.25 mmol, 312 equiv.) was added. After stirring at -30°C for one hour, the reaction flask was removed from the cryogenic reactor and brought to room temperature. Methyl methacrylate monomer (1.01 mL, 9.38 mmol, 52 equiv.) was added, and the reaction was stirred for four hours at 25°C. The mixture was quenched with methanol and washed three times. The precipitated polymer was dried to constant weight to obtain the ABABA type acrylate block polymer.

[0071] Yield > 99%. NMR characterization showed that the block ratio of methyl methacrylate to n-butyl acrylate was 2:8, which met the designed block ratio, with the interstitial structure ratio (rr) of segment A accounting for 74%. GPC characterization showed that the number-average molecular weight of the product was 115624 g / mol, and the molecular weight distribution was 1.34.

[0072] Example 5

[0073] The preparation steps of the ABABA type acrylate thermoplastic elastomer in this embodiment are as follows:

[0074] Under an argon atmosphere, 60 mL of toluene solvent, 4.5 mL of pentamethyldiethylenetriamine (18 mmol, 100 equiv.), 3.9 mL of i-BuAl(BHT)2 (1.4 mmol, 8 equiv.), 0.14 mL of s-BuLi (0.18 mmol, 1 equiv.), and 1.01 mL of methyl methacrylate (9.38 mmol, 52 equiv.) were added sequentially to a 500 mL Schlenk flask. After stirring at 25 °C for one hour, the reaction flask was transferred to a cryogenic reactor, where 8.06 mL of n-butyl acrylate (56.25 mmol, 31 equiv.) was added. After stirring at -30°C for one hour, the reaction flask was removed from the cryogenic reactor and brought to room temperature. Methyl methacrylate monomer (1.01 mL, 9.38 mmol, 52 equiv.) was added, and the reaction was stirred for another three hours at 25°C. The reaction flask was then transferred back to the cryogenic reactor, and n-butyl acrylate (8.06 mL, 56.25 mmol, 312 equiv.) was added. After stirring at -30°C for one hour, the reaction flask was removed from the cryogenic reactor and brought to room temperature. Methyl methacrylate monomer (1.01 mL, 9.38 mmol, 52 equiv.) was added, and the reaction was stirred for four hours at 25°C. The mixture was quenched with methanol and washed three times. The precipitated polymer was dried to constant weight to obtain the ABABA type acrylate block polymer.

[0075] Yield > 99%. NMR characterization showed that the block ratio of methyl methacrylate to n-butyl acrylate was 2:8, which met the designed block ratio, with the interstitial structure ratio (rr) of segment A accounting for 74%. GPC characterization showed that the number-average molecular weight of the product was 118925 g / mol, and the molecular weight distribution was 1.26.

[0076] Example 6

[0077] The preparation steps of the ABABA type acrylate thermoplastic elastomer in this embodiment are as follows:

[0078] Under an argon atmosphere, 60 mL of toluene solvent, 2 mL of pentamethyldiethylenetriamine (10 mmol, 55 equiv.), 3.9 mL of i-BuAl(BHT)2 (1.40 mmol, 8 equiv.), 0.14 mL of s-BuLi (0.18 mmol, 1 equiv.), and 1.01 mL of methyl methacrylate (9.38 mmol, 52 equiv.) were added sequentially to a 500 mL Schlenk flask. After stirring at 25 °C for one hour, the reaction flask was transferred to a cryogenic reactor, where 8.06 mL of n-butyl acrylate (56.25 mmol, 312 mmol) was added. After stirring at -30°C for one hour, the reaction flask was removed from the cryogenic reactor and brought to room temperature. Methyl methacrylate monomer (1.01 mL, 9.38 mmol, 52 equiv.) was added, and the reaction was stirred for another three hours at 25°C. The reaction flask was then transferred to the cryogenic reactor again, and n-butyl acrylate (8.06 mL, 56.25 mmol, 312 equiv.) was added. After stirring at -30°C for one hour, the reaction flask was removed from the cryogenic reactor and brought to room temperature. Methyl methacrylate monomer (1.01 mL, 9.38 mmol, 52 equiv.) was added, and the reaction was stirred for four hours at 25°C. The mixture was quenched with methanol and washed three times. The precipitated polymer was dried to constant weight to obtain the ABABA type acrylate block polymer.

[0079] Yield > 99%. NMR characterization showed that the block ratio of methyl methacrylate to n-butyl acrylate was 2:8, which met the designed block ratio, with the interstitial structure ratio (rr) of segment A accounting for 75%. GPC characterization showed that the number-average molecular weight of the product was 107505 g / mol, and the molecular weight distribution was 1.33.

[0080] Example 7

[0081] The preparation steps of the ABABA type acrylate thermoplastic elastomer in this embodiment are as follows:

[0082] Under an argon atmosphere, 60 mL of ethylene glycol dimethyl ether solvent, amine auxiliary pentamethyldiethylenetriamine (2 mL, 10 mmol, 55 equiv.), co-catalyst i-BuAl(BHT)2 (3.9 mL, 1.4 mmol, 8 equiv.), initiator s-BuLi (0.14 mL, 0.18 mmol, 1 equiv.), and hard segment monomer methyl methacrylate (1.01 mL, 9.38 mmol, 52 equiv.) were added sequentially to a 500 mL Schlenk flask. After stirring at 25 °C for one hour, the reaction flask was transferred to a cryogenic reactor, where n-butyl acrylate monomer (8.06 mL, 56.25 mmol, 31 equiv.) was added. After stirring at -30°C for one hour, the reaction flask was removed from the cryogenic reactor and brought to room temperature. Methyl methacrylate monomer (1.01 mL, 9.38 mmol, 52 equiv.) was added, and the reaction was stirred for another three hours at 25°C. The reaction flask was then transferred back to the cryogenic reactor, and n-butyl acrylate (8.06 mL, 56.25 mmol, 312 equiv.) was added. After stirring at -30°C for one hour, the reaction flask was removed from the cryogenic reactor and brought to room temperature. Methyl methacrylate monomer (1.01 mL, 9.38 mmol, 52 equiv.) was added, and the reaction was stirred for four hours at 25°C. The mixture was quenched with methanol and washed three times. The precipitated polymer was dried to constant weight to obtain the ABABA type acrylate block polymer.

[0083] Yield > 99%. NMR characterization showed that the block ratio of methyl methacrylate to n-butyl acrylate was 2:8, which met the designed block ratio, with the interstitial structure ratio (rr) of segment A accounting for 78%. GPC characterization showed that the number-average molecular weight of the product was 116219 g / mol, and the molecular weight distribution was 1.57.

[0084] Example 8

[0085] The preparation steps of the ABABA type acrylate thermoplastic elastomer in this embodiment are as follows:

[0086] Under an argon atmosphere, 60 mL of anisole solvent, 2 mL of pentamethyldiethylenetriamine (10 mmol, 55 equiv.), 3.9 mL of i-BuAl(BHT)2 (1.4 mmol, 8 equiv.), 0.14 mL of s-BuLi (0.18 mmol, 1 equiv.), and 1.01 mL of methyl methacrylate (9.38 mmol, 52 equiv.) were added sequentially to a 500 mL Schlenk flask. After stirring at 25 °C for one hour, the reaction flask was transferred to a cryogenic reactor, where 8.06 mL of n-butyl acrylate (56.25 mmol, 312 mmol) was added. After stirring at -30°C for one hour, the reaction flask was removed from the cryogenic reactor and brought to room temperature. Methyl methacrylate monomer (1.01 mL, 9.38 mmol, 52 equiv.) was added, and the reaction was stirred for another three hours at 25°C. The reaction flask was then transferred to the cryogenic reactor again, and n-butyl acrylate (8.06 mL, 56.25 mmol, 312 equiv.) was added. After stirring at -30°C for one hour, the reaction flask was removed from the cryogenic reactor and brought to room temperature. Methyl methacrylate monomer (1.01 mL, 9.38 mmol, 52 equiv.) was added, and the reaction was stirred for four hours at 25°C. The mixture was quenched with methanol and washed three times. The precipitated polymer was dried to constant weight to obtain the ABABA type acrylate block polymer.

[0087] Yield > 99%. NMR characterization showed that the block ratio of methyl methacrylate to n-butyl acrylate was 2:8, which met the designed block ratio, with the interstitial structure ratio (rr) of segment A accounting for 77%. GPC characterization showed that the number-average molecular weight of the product was 114,132 g / mol, and the molecular weight distribution was 1.70.

[0088] Example 9

[0089] The preparation steps of the ABABA type acrylate thermoplastic elastomer in this embodiment are as follows:

[0090] Under an argon atmosphere, 37.5 mL of toluene solvent, 2 mL of pentamethyldiethylenetriamine (10 mmol, 55 equiv.), 3.9 mL of i-BuAl(BHT)2 (1.404 mmol, 8 equiv.), 0.14 mL of s-BuLi (0.18 mmol, 1 equiv.), and 1.01 mL of methyl methacrylate (9.38 mmol, 52 equiv.) were added sequentially to a 500 mL Schlenk flask. After stirring at 25 °C for one hour, the reaction flask was transferred to a cryogenic reactor, where 4.7 mL of n-butyl acrylate (32.8 mmol, 18 equiv.) was added. After stirring at -30°C for one hour, the reaction flask was removed from the cryogenic reactor and brought to room temperature. Methyl methacrylate monomer (1.01 mL, 9.38 mmol, 52 equiv.) was added, and the reaction was stirred for another three hours at 25°C. The reaction flask was then transferred back to the cryogenic reactor, and n-butyl acrylate (4.7 mL, 32.8 mmol, 182 equiv.) was added. After stirring at -30°C for one hour, the reaction flask was removed from the cryogenic reactor and brought to room temperature. Methyl methacrylate monomer (1.01 mL, 9.38 mmol, 52 equiv.) was added, and the reaction was stirred for four hours at 25°C. The mixture was quenched with methanol and washed three times. The precipitated polymer was dried to constant weight to obtain the ABABA type acrylate block polymer.

[0091] Yield > 99%. NMR characterization showed that the block ratio of methyl methacrylate to n-butyl acrylate was 3:7, which met the designed block ratio, with the interstitial structure ratio (rr) of segment A accounting for 76%. GPC characterization showed that the number-average molecular weight of the product was 78429 g / mol, and the molecular weight distribution was 1.28.

[0092] Example 10

[0093] The preparation steps of the ABABA type acrylate thermoplastic elastomer in this embodiment are as follows:

[0094] Under an argon atmosphere, 30 mL of toluene solvent, 2 mL of pentamethyldiethylenetriamine (10 mmol, 55 equiv.), 3.9 mL of i-BuAl(BHT)2 (1.4 mmol, 8 equiv.), 0.14 mL of s-BuLi (0.18 mmol, 1 equiv.), and 1.01 mL of methyl methacrylate (9.38 mmol, 52 equiv.) were added sequentially to a 500 mL Schlenk flask. After stirring at 25 °C for one hour, the reaction flask was transferred to a cryogenic reactor, where 3 mL of n-butyl acrylate (21.09 mmol, 11 equiv.) was added. The reaction mixture was stirred at -30°C for one hour, then removed from the cryogenic reactor and brought to room temperature. Methyl methacrylate monomer (1.01 mL, 9.38 mmol, 52 equiv.) was added, and the reaction was stirred again. After stirring at 25°C for three hours, the reaction mixture was transferred back to the cryogenic reactor, and n-butyl acrylate (3 mL, 21.09 mmol, 117 equiv.) was added. After stirring at -30°C for one hour, the reaction mixture was removed from the cryogenic reactor and brought to room temperature. Methyl methacrylate monomer (1.01 mL, 9.38 mmol, 52 equiv.) was added, and the reaction was stirred at 25°C for four hours. The mixture was quenched with methanol and washed three times. The precipitated polymer was dried to constant weight to obtain the ABABA type acrylate block polymer.

[0095] Yield > 99%. NMR characterization showed that the block ratio of methyl methacrylate to n-butyl acrylate was 4:6, which met the designed block ratio, with the interstitial structure ratio (rr) of segment A accounting for 75%. GPC characterization showed that the number-average molecular weight of the product was 59413 g / mol, and the molecular weight distribution was 1.25.

[0096] The above description is merely a preferred embodiment of the present invention. These specific embodiments are different implementations based on the overall concept of the present invention, and the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A controllable preparation method for an ABABA type acrylate thermoplastic elastomer, characterized in that, The method is performed according to the following steps: Under anhydrous and oxygen-free conditions, solvents, amine auxiliaries, cocatalysts, initiators, and comonomers are added to a reactor. The comonomers are divided into A-segment and B-segment, and are added sequentially in the order of A-segment, B-segment, A-segment, B-segment, A-segment, and so on, reacting at a certain temperature for a certain time before adding the next monomer. After the polymerization reaction is completed, the mixture is quenched, concentrated, washed, and vacuum dried to obtain an ABABA type acrylate thermoplastic elastomer. The A-segment monomer is an alkyl methacrylate, and the B-segment monomer is an alkyl acrylate. The amine auxiliaries include one or more of the following structures: ， The initiator includes one or more of the following: n-butyllithium, sec-butyllithium, tert-butyllithium, tert-butoxide lithium, methyllithium, ethyllithium, n-propyllithium, isopropyllithium, phenyllithium, benzyllithium, and naphthyllithium. The cocatalyst is prepared by AlR3 and phenolic reagent in a molar ratio of 1:(1-5) at a specific temperature of -30~25 ℃. The molar ratio of alkyl methacrylate monomer to alkyl acrylate monomer is 1:(1.5~4), the molar ratio of amine auxiliaries to initiators is 1:(25~100), the molar ratio of initiator to total molar amount of comonomer is 1:(400~800), and the ratio of total mass of comonomer to mass of solvent is 1:

3.

2. The method according to claim 1, characterized in that, Alkyl methacrylates include one or more of the following structures: ， Alkyl acrylates include one or more of the following structures: 。 3. The method according to claim 1, characterized in that, The solvent is one or more of benzene, toluene, ethylbenzene, xylene, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and diethoxymethane.

4. The method according to claim 3, characterized in that, The amine promoter is one of pentamethyldiethylenetriamine, pentamethyldipropylenetriamine, hexamethylphosphoryltriamine, and N,N,N',N'-tetramethylethylenediamine; the initiator is one of n-butyllithium, sec-butyllithium, and tert-butyllithium; the solvent is toluene or ethylene glycol dimethyl ether; and the co-catalyst is prepared by mixing AlR3 and a phenolic reagent in a molar ratio of 1:

2.

5. The method according to claim 4, characterized in that, The amine auxiliaries are pentamethyldiethylenetriamine or hexamethylphosphoryltriamine, and the initiator is sec-butyllithium.

6. The method according to claim 3, characterized in that, AlR3 is one of triethylaluminum, trimethylaluminum, triisobutylaluminum, diethylaluminum chloride, diethylaluminum chloride, and methylaluminoxane; the phenolic reagent is one of arylphenols with different substituents.

7. The method according to claim 6, characterized in that, AlR3 is triisobutylaluminum or triethylaluminum, and the phenolic reagents include one of 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-p-methylphenol, 2,6-di-tert-butyl-p-ethylphenol, 2,4,6-tri-tert-butylphenol, 2,6-diisopropylphenol, 2-tert-butylphenol, 2-tert-butyl-5-methylphenol, and 2,6-di-tert-butyl-4-nitrophenol.

8. The method according to claim 7, characterized in that, The phenolic reagents are 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-p-methylphenol, 2,6-di-tert-butyl-p-ethylphenol, or 2,4,6-tri-tert-butylphenol.

9. The method according to claim 1, characterized in that, The total aggregation time is 3~24 hours.

10. The method according to claim 9, characterized in that, The total aggregation time was 10 hours.

11. The ABABA type acrylate thermoplastic elastomer obtained by the method according to any one of claims 1-10, characterized in that, The elastic body M n The concentration ranges from 10,000 to 500,000 g / mol, the PDI ranges from 1.1 to 2.0, and the syndiotactic regularity (rr) of the A-block is 70% to 80%.

12. The ABABA type acrylate thermoplastic elastomer according to claim 11, characterized in that, That M n The concentration was 60,000 to 120,000 g / mol, the PDI was 1.1 to 1.7, and the syndiotactic regularity (rr) of the A block was 73 to 78%.

13. The application of the ABABA type acrylate thermoplastic elastomer obtained by the method according to any one of claims 1-10 in the fields of aerospace, defense and military industry, automotive parts, lighting products and plastic modification.

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