Polymer with main chain containing photoresponse group and preparation method of segmented copolymer of polymer

Abstract

The invention discloses a polymer with a main chain containing a photoresponse group and a preparation method of a segmented copolymer of the polymer, and belongs to the technical field of polymer synthesis. According to the preparation method provided by the invention, an allyl sulfur macrocyclic monomer and a vinyl monomer are used as comonomers, trithiocarbonate is used as a chain transfer agent, and in the presence of a photosensitizer and an organic solvent, free radical ring-opening copolymerization is performed to realize polymerization to obtain the polymer with the main chain containing the photoresponse group; the photoresponse group can be directly embedded into the main chain of the polymer in the process, so that the polymer is endowed with the photoresponse characteristic. The obtained polymer with the main chain containing the photoresponse group has the characteristics of adjustable molecular weight and narrow molecular weight distribution (low dispersity), and is suitable for the fields of biological medicines and the like. The block copolymer is obtained by carrying out free radical ring-opening copolymerization on a polymer with a main chain containing a photoresponse group, an allyl sulfur macrocyclic monomer, a vinyl monomer and a chain transfer agent in the presence of a photosensitizer and an organic solvent.

Description

Technical Field

[0001] This invention belongs to the field of polymer synthesis technology, and in particular relates to a method for preparing a polymer with photoresponsive groups in its main chain and its block copolymers. Background Technology

[0002] Over the past four decades, global annual plastic production has approached 400 million tons, of which approximately 70% is general-purpose plastics based on vinyl monomers (such as polyethylene, polyvinyl chloride, polystyrene, and their copolymers). These materials are widely used in almost all industrial and consumer sectors, including packaging, building materials, and daily consumer goods, due to their low cost, excellent mechanical properties, and mature processing technologies. However, the molecular structure of traditional vinyl polymers is based on a saturated carbon-carbon backbone, resulting in a relatively simple chemical structure. This limits their functions to mechanical support and insulation protection, lacking responsiveness to external environmental signals and failing to meet the advanced demands of modern technology for intelligent and functional materials. [1] (ACS Sustainable Chem. Eng. 2020, 8, 3494-3511). Against this backdrop, developing photoresponsive polymers with both high performance and environmental friendliness has become a cutting-edge direction in materials science. In recent years, the technical route based on macrocyclic monomer radical ring-opening polymerization and vinyl monomer copolymerization has provided a highly promising solution for constructing novel main-chain photoresponsive polymers.

[0003] To overcome this limitation, introducing photoresponsive groups (such as azobenzene, coumarins, and anthracene) into polymers to endow them with active intelligent properties such as photochromism, photocontrolled deformation, and photoresponsive drug release has become a cutting-edge direction in polymer functionalization modification. Currently, common strategies often use photoresponsive groups as side links, but this may affect the regularity of the main chain or face problems such as functional group migration and insufficient stability. In contrast, directly embedding photoresponsive units into the polymer main chain not only ensures the stable existence and efficient synergy of functional groups but also allows for precise control of the photophysical properties and macroscopic performance of the material at the molecular skeleton level. Therefore, developing an efficient and controllable synthetic method to achieve the direct embedding and sequence control of photoresponsive groups in the traditional vinyl polymer main chain has significant scientific value and application potential for developing next-generation high-performance smart materials.

[0004] Photocontrolled polymerization has become an important alternative to thermally initiated polymerization due to its economic and versatility advantages. By combining the principle of reversible deactivated radical polymerization, photocontrolled radical polymerization can achieve precise control of molecular weight and main chain structure under mild conditions, providing a new approach for constructing complex macromolecular structures.

[0005] Therefore, this invention discloses a novel photo-controlled polymerization strategy based on allyl thiomacrocyclic monomers. This monomer can be used as a general-purpose cyclic monomer under light-triggered conditions, and can be efficiently copolymerized with various vinyl monomers such as acrylates and acrylamides. The resulting copolymers possess both main-chain photoresponsive properties and biodegradability, providing a theoretical basis and technical support for the development of high-performance photoresponsive group-containing materials such as environmentally responsive medical stents and smart packaging. Summary of the Invention

[0006] To address the technical problems existing in the prior art, the primary objective of this invention is to provide a method for preparing a polymer with photoresponsive groups in its main chain.

[0007] Another object of the present invention is to provide a polymer with photoresponsive main chain groups prepared by the above method.

[0008] Another object of the present invention is to provide a method for preparing block copolymers from the above-mentioned polymers containing photoresponsive groups in the main chain.

[0009] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: This invention provides a method for preparing a polymer with photoresponsive groups in the main chain. Allyl thiomacyclomonomer and vinyl monomer are used as comonomers, and trithiocarbonate is used as a chain transfer agent. In the presence of photosensitizer and organic solvent, polymerization is achieved through free radical ring-opening copolymerization, and photoresponsive group sequence units are directly embedded into the polymer main chain to obtain a polymer with photoresponsive groups in the main chain. Allyl thio macrocyclic monomers include at least one of M1, M2, or M3: , , ; The vinyl monomer includes at least one of M4, M5, M6, M7, M8, or M9: , , , , , .

[0010] Preferably, the chain transfer agent includes one of CTA1, CTA2, CTA3, CTA4, or CTA5: , , , , .

[0011] Preferably, the number-average molecular weight of the polymer containing photoresponsive groups in the main chain is 0.32 million to 3.96 million.

[0012] Preferably, the dispersion of the polymer containing photoresponsive groups in the main chain is 1.05~1.54.

[0013] Dispersion can determine whether a polymerization reaction is controllable. A dispersion of less than 1.3 indicates that the polymerization reaction is controllable, and that the chain initiation, propagation, and termination processes are highly synchronized during polymerization. For example, in living polymerization, all chains are simultaneously initiated and grow at a uniform rate, with no random termination or chain transfer, and no other side reactions. Polymers with narrow distributions typically have more uniform chain lengths and may exhibit higher tensile strength and more defined thermal transition points. Narrow distributions usually indicate a high level of reaction control and product homogeneity, resulting in more uniform and stable polymers.

[0014] Preferably, the molar ratio of vinyl monomer, allyl thiomacrocyclic monomer to chain transfer agent is 100:2:1 to 400:8:1.

[0015] More preferably, the molar ratio of the vinyl monomer, the allyl thiomacyclomonomer, and the chain transfer agent is 100:2:1 to 200:4:1.

[0016] Preferably, the concentration of the initiator is 50 ppm to 200 ppm.

[0017] More preferably, the concentration of the initiator is one of 50 ppm, 100 ppm or 200 ppm.

[0018] Preferably, the organic solvent is selected from one or more of N,N-dimethylformamide, dimethyl sulfoxide, dioxane, tetrahydrofuran, or toluene.

[0019] Preferably, the amount of organic solvent added is 50~150 uL.

[0020] Preferably, the free radical ring-opening copolymerization reaction takes 3 to 12 hours.

[0021] More preferably, the time for the free radical ring-opening copolymerization reaction is either 3 h or 12 h.

[0022] The present invention also provides a polymer with photoresponsive groups in the main chain prepared by the above method, the general structural formula of which is as follows: ; Among them, R 1 Groups with any of the following structures: , , , Among them, R 2 Groups with any of the following structures: , , , , ,

[0023] Where --- represents the connecting chemical bond; where n / m is 10~100, n represents the degree of polymerization of M1, M2 or M3, and m represents the degree of polymerization of M4, M5, M6, M7, M8 or M9.

[0024] Polymers containing photoresponsive groups in their main chain possess tunable molecular weight and narrow dispersion characteristics. The insertion of functional sequences can be selected based on performance control. Furthermore, the molecular weight can be chosen according to specific application scenarios, and the polymers, once prepared into materials, exhibit low dispersion and uniformity, making them suitable for fields such as biomedicine.

[0025] The present invention also provides a method for preparing a block copolymer, wherein the above-mentioned polymer containing photoresponsive groups in the main chain, allyl thio macrocyclic monomer, vinyl monomer, and chain transfer agent are subjected to free radical ring-opening copolymerization in the presence of photosensitizer and organic solvent to obtain a block copolymer; The allyl thio macrocyclic monomer includes at least one of M1, M2 or M3; The vinyl monomer includes at least one of M4, M5, M6, M7, M8 or M9; Chain transfer agents include one of CTA1, CTA2, CTA3, CTA4, or CTA5; The photosensitizer is Eosin Y; The organic solvent is selected from one or more of N,N-dimethylformamide, dimethyl sulfoxide, dioxane, tetrahydrofuran, or toluene.

[0026] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a method for preparing a polymer with photoresponsive groups in its main chain. The photoresponsive groups are directly embedded into the polymer main chain via a free radical ring-opening copolymerization reaction. This method allows for flexible control of the embedding ratio of the photoresponsive groups in the polymer chain according to target performance requirements. The prepared polymer with photoresponsive groups in its main chain has an adjustable molecular weight and narrow molecular weight distribution, low dispersion, and uniform material composition, making it suitable for applications in biomedicine and other fields. Attached Figure Description

[0027] Figure 1 GPC curves of copolymerization reaction of allyl thiomacrocyclic monomer M1 and vinyl monomer M4 under different chain transfer agent conditions.

[0028] Figure 2 GPC curves of copolymerization reaction of allyl thiomacrocyclic monomer M1 and vinyl monomer M4 under different organic solvent conditions.

[0029] Figure 3 GPC curves for the copolymerization reaction of allyl thiomacrocyclic monomer M1 and vinyl monomer M4 under different photosensitizer concentrations.

[0030] Figure 4 GPC curves for copolymerization of allyl thiomacrocyclic monomer M1 with different types of vinyl monomers.

[0031] Figure 5 The graph shows the relationship between monomer conversion and reaction time in the copolymerization reaction of allyl sulfide macrocyclic monomer M1 and vinyl monomer M4.

[0032] Figure 6 The graph shows the relationship between the molecular weight of the polymer and the monomer conversion rate in the copolymerization reaction of allyl sulfide macrocyclic monomer M1 and vinyl monomer M4.

[0033] Figure 7 GPC curves for preparing block copolymer P4-b-P2. Detailed Implementation

[0034] The present invention is further illustrated below with reference to specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions in the art or as recommended by the manufacturer; the raw materials and reagents used, unless otherwise specified, are all commercially available from the conventional market. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention are within the scope of protection claimed by the present invention.

[0035] Example 1 Preparation of allyl thiomacrocyclic monomers.

[0036]

[0037] This embodiment provides a specific method for synthesizing the allyl thiomacrocyclic monomer, which requires the prior preparation of molecule 3. The specific preparation method for molecule 3 is as follows: N-hydroxycarbamate tert-butyl ester (6.65 g, 50 mmol), sodium carbonate (13.25 g, 125 mmol), and N,N-dimethylformamide (DMF) (100 mL) are added to a 250 mL single-necked round-bottom flask. The mixture is stirred thoroughly, and then bromopropyne (5.6 mL, 65 mmol) is slowly added dropwise. The mixture is stirred at room temperature for 48 hours. After the reaction is complete, the reaction solution is poured into a large amount of water (250 mL) and extracted with ethyl acetate (3 × 80 mL). The combined organic phases are washed three times with saturated brine, dried over anhydrous Na₂SO₄, allowed to stand, filtered, and concentrated under vacuum. The crude product is separated and purified by column chromatography to obtain a colorless oily liquid 1 (6.84 g, 80% yield). NMR characterization results: 1 H NMR (400 MHz, CDCl3): δ 3.71 (d, J = 2.5 Hz, 2H), 1.83 (t, J = 2.4 Hz, 1H), 0.73 (s, 9H). Add 1 (3.42 g, 20 mmol) to a 50 mL single-necked round-bottom flask, add 20 mL of DMF, stir to dissolve, and transfer to an ice-water bath. Add sodium hydride (1.2 g, 30 mmol) to the above solution in two portions. Stir the reaction mixture at 0 °C for 1 hour. After stirring, allow the reaction mixture to return to room temperature, then slowly add the reaction mixture to 30 mL of DMF containing 10.6 g, 50 mmol of 1,4-dibromo-2-butene. Stir at room temperature for 12 hours. Stop the reaction, quench the reaction mixture with water, and extract with ethyl acetate (3 × 50 mL). Wash the organic phase three times with saturated brine, dry with anhydrous Na₂SO₄, allow to stand, filter, and concentrate under vacuum. Separate and purify the crude product by column chromatography to obtain a colorless oily liquid 2 (4.08 g, yield 67%). NMR characterization results: 1 H NMR (400 MHz, CDCl3): δ 5.88–5.66 (m, 2H), 4.38(d, J = 2.5 Hz, 2H), 4.03 (d, J = 5.4 Hz, 2H), 3.86 (d, J = 6.5 Hz, 2H), 2.45(t, J = 2.4 Hz, 1H), 1.40 (s, 9H). Compound 2 (4.56 g, 15 mmol) and 50 mL of DMF were added to a 250 mL round-bottom flask and stirred to dissolve. β-mercaptoethanol (1.4 mL, 19.5 mmol) and K₂CO₃ (2.49 g, 18 mmol) were then added, and the mixture was reacted at room temperature for 12 hours. The reaction was stopped, and the mixture was poured into a large volume of water. Extraction was performed using ethyl acetate (3 × 50 mL). The organic phase was washed three times with saturated brine, dried over anhydrous Na₂SO₄, allowed to stand, filtered, and concentrated under vacuum. The crude product was separated and purified by column chromatography to obtain a yellow oily liquid 3 (3.93 g, 87% yield). NMR characterization results: 1 H NMR (400 MHz, CDCl3): δ 5.53–5.64(m, 2H), 4.41 (d, J = 2.3 Hz,2H), 4.04 (d, J = 4.9 Hz,2H), 3.63 (t, J = 6.3Hz,2H), 3.08 (d, J = 5.7 Hz,2H), 2.65 – 2.50 (m,3H), 2.47 (t, J = 2.4 Hz,1H),1.44 (s, 9H). 1.1 Preparation of allyl thiomacrocyclic monomer M1

[0038] To a 250 mL round-bottom flask, add compound 4,4'-(1,2-diphenylvinyl-1,2-diyl)biphenol (10.9 g, 30 mmol), potassium carbonate (12.4 g, 90 mmol), potassium iodide (2.49 g, 15 mmol), tetrabutylammonium bromide (TBAB, 2.42 g, 7.5 mmol), 2-bromoethanol (8.5 mL, 120 mmol), and DMF (120 mL), and stir thoroughly to dissolve. Reflux the reaction mixture and stir for 15 hours. After the reaction is complete, pour the reaction mixture into a large volume of water (250 mL) and extract with ethyl acetate (3 × 80 mL). Wash the organic phase three times with saturated brine, dry to anhydrous Na₂SO₄, allow to stand, filter, and concentrate under vacuum. Separate and purify the crude product by column chromatography to give white solid 4 (8.82 g, 65% yield). NMR characterization results: 1 H NMR (400 MHz, CDCl3): δ 7.12 – 7.08 (m, 6H), 7.05 (d, 4H), 6.97 (d, J =8.4 Hz, 4H), 6.68 (d, J = 8.4 Hz, 4H), 4.00 (t, J = 4.5 Hz, 4H), 3.90 (t, J =4.7 Hz, 4H). Compound 4 (9.04 g, 20 mmol), EDC·HCl (5.75 g, 30 mmol), 4-dimethylaminopyridine (0.12 g, 1 mmol), and dichloromethane (70 mL) were added to a 250 mL round-bottom flask and stirred thoroughly to dissolve. Azideacetic acid (2.02 g, 20 mmol) was dissolved in 80 mL of dichloromethane and transferred to a constant-pressure dropping funnel, then slowly added dropwise to the round-bottom flask. After the addition was complete, the reaction was continued for 12 hours. After the reaction was complete, the resulting solution was washed once with 1 M HCl, once with saturated sodium bicarbonate solution, and once with saturated brine. It was dried over anhydrous Na₂SO₄, allowed to stand, filtered, and concentrated under vacuum. The crude product was separated and purified by column chromatography to obtain a pale yellow oily liquid 5 (4.68 g, yield 46%). NMR characterization results: 1 H NMR (400 MHz, CDCl3): δ 7.12 – 7.07 (m, 6H), 7.02 (d, J = 7.2 Hz, 4H), 6.96 (d, J = 8.7 Hz, 4H), 6.67 (d, J = 8.6 Hz, 4H), 4.52 (t, J = 4.6 Hz, 2H), 4.15(t, J = 4.6 Hz, 2H), 4.02 (t, J = 4.4 Hz, 2H), 3.93 (t, J = 4.7 Hz, 2H), 3.90(s, 2H). In a 100 mL single-necked round-bottom flask, 5 (8.03 g, 15 mmol), succinic anhydride (1.8 g, 18 mmol), 4-(dimethylamino)pyridine (DMAP, 2.75 g, 22.5 mmol), and dichloromethane (60 mL) were added and stirred to dissolve. The mixture was stirred at room temperature for 12 hours. After the reaction was complete, the resulting solution was washed once with 1 M HCl and twice with saturated brine, dried over anhydrous Na₂SO₄, allowed to stand, filtered, and concentrated under vacuum to obtain a colorless oily liquid. In a 250 mL round-bottom flask, the above colorless oily liquid (6.36 g, 10 mmol) and 100 mL of DCM were added and stirred thoroughly to dissolve. Then, EDC·HCl (2.88 g, 15 mmol) and DMAP (0.06 g, 0.5 mmol) were added and stirred to dissolve. Finally, 3 (3.62 g, 12 mmol) was added to the mixture, and the mixture was reacted at room temperature for 15 hours. After the reaction was complete, 100 mL of DCM was added to the reaction solution for dilution. The resulting solution was washed once with 1 M HCl, once with saturated sodium bicarbonate solution, and once with saturated saline solution. The solution was dried over anhydrous Na₂SO₄, allowed to stand, filtered, and concentrated under vacuum. The crude product was separated and purified by column chromatography to obtain a colorless oily liquid 6 (5.97 g, yield 65%). NMR characterization results:1 H NMR (400 MHz, CDCl3): δ 7.05 – 6.96 (m, 10H), 6.95 – 6.89 (m, 4H), 6.65 – 6.57 (m, 4H), 5.70 – 5.54 (m, 2H), 4.53– 4.38 (m, 4H), 4.36 (t, J = 4.7 Hz, 2H), 4.17 (t, J = 6.8 Hz, 2H), 4.11 –4.01 (m, 6H), 3.84 (s, 2H), 3.17 – 3.04 (m, 2H), 2.67 – 2.56 (m, 6H), 2.50(t, J = 2.3 Hz, 1H), 1.47 (s, 9H). Compound 6 (2.76 g, 3 mmol) and 300 mL of DCM were added to a 500 mL round-bottom flask and stirred thoroughly to dissolve. The solution was degassed with nitrogen for 15 min. Tris[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]amine (TBTA, 63.7 mg, 0.12 mmol) and copper(I) tetraacetonitrile hexafluorophosphate (55.9 mg, 0.15 mmol) were added to the solution. The solution was degassed again with nitrogen and stirred at 55 °C for 36 h under nitrogen. The reaction mixture was cooled to room temperature, quenched with methanol, and then concentrated under vacuum. The crude product was separated and purified by column chromatography to give a white solid 7 (1.27 g, 46% yield). NMR characterization results: 1 H NMR (400 MHz, CDCl3): δ 7.78 (s, 1H), 7.10 – 7.04 (m,6H), 7.03 – 6.99 (m, 4H), 6.97 – 6.91 (m, 4H), 6.69 – 6.59 (m, 4H), 5.62 –5.48 (m, 2H), 5.20 (s, 2H), 5.01 (s, 2H), 4.52 (t, J = 4.5 Hz, 2H), 4.38 (t,J = 4.6 Hz, 2H), 4.15 (t, J = 6.5 Hz, 4H), 4.09 (t, J = 4.7 Hz, 2H), 3.96 (d,J = 5.5 Hz, 2H), 3.10 (d, J = 6.3 Hz, 2H), 2.63 (d, J = 7.7 Hz, 6H), 1.50 (s,9H). Compound 7 (3.67 g, 4 mmol) and 30 mL of DCM were added to a 100 mL round-bottom flask and stirred thoroughly to dissolve. Trifluoroacetic acid (1.5 mL, 20 mmol) was slowly added dropwise at 0 °C. After the addition was complete, the mixture was stirred at room temperature for 36 hours. After the reaction was complete, the reaction was quenched with saturated sodium bicarbonate solution and extracted with DCM (3 × 40 mL). The combined organic phases were washed with saturated brine (30 mL), dried over anhydrous Na₂SO₄, allowed to stand, filtered, and concentrated under vacuum. A colorless oily liquid was obtained. The above colorless oily liquid (2.46 g, 3 mmol), triethylamine (2.1 mL, 15 mmol), and 30 mL of DCM were added to a 100 mL round-bottom flask and stirred thoroughly to dissolve. The mixture was stirred in an ice bath. Acryloyl chloride (1.2 mL, 15 mmol) was slowly added, and the mixture was stirred at room temperature for 15 hours. After the reaction was complete, the reaction was quenched with saturated sodium bicarbonate solution and extracted with DCM (3 × 40 mL). The combined organic phases were washed with saturated brine (30 mL), dried over anhydrous Na₂SO₄, allowed to stand, filtered, and concentrated under vacuum. The crude product was separated and purified by column chromatography to give a white solid M1 (1.18 g, 45% yield). NMR characterization results: 1 H NMR (400 MHz, CDCl3): δ 7.81 (s, 1H), 7.11 – 7.05 (m, 6H), 7.05 –6.99 (m, 4H), 6.98 – 6.87 (m, 4H), 6.74 (dd, J = 17.0, 10.4 Hz, 1H), 6.69 – 6.62 (m, 4H), 6.40 (dd, J = 17.0, 2.2 Hz, 1H), 5.74 (dd, J = 10.4, 2.0 Hz, 1H), 5.70 – 5.57 (m, 2H), 5.22 (s, 2H), 5.04 (s, 2H), 4.57 – 4.46 (m, 2H),4.38 (t, J = 4.6 Hz, 2H), 4.31 (d, J = 5.3 Hz, 2H), 4.20 – 4.07 (m, 6H), 3.14 (d, J = 6.1 Hz, 2H), 2.68 – 2.58 (m, 6H). 1.2 Preparation of allyl thiomacrocyclic monomer M2

[0039] In a 100 mL single-necked round-bottom flask, 3.53 g (15 mmol) of 2-tert-butyldimethylsilyloxyethanol, 2.20 g (22 mmol) of succinic anhydride, 0.49 g (4 mmol) of 4-(dimethylamino)pyridine (DMAP) and 60 mL of DCM were added and stirred until dissolved. The mixture was stirred at room temperature for 12 hours. After the reaction was complete, the resulting solution was washed once with 1 M HCl and twice with saturated brine, dried over anhydrous Na₂SO₄, allowed to stand, filtered, and concentrated under vacuum to obtain a colorless oily liquid. Add the above colorless oily liquid (2.76 g, 10 mmol) and 100 mL of DCM to a 250 mL round-bottom flask, stir thoroughly to dissolve, then add EDC·HCl (3.6 g, 18.75 mmol) and DMAP (76.4 mg, 0.625 mmol), stir to dissolve, and then add 3 (3.77 g, 12.5 mmol) to the mixture. React at room temperature for 15 hours. After the reaction is complete, dilute the reaction solution with 100 mL of DCM, wash the resulting solution once with 1 M HCl, once with saturated sodium bicarbonate solution, and once with saturated brine. Dry with anhydrous Na₂SO₄, allow to stand, filter, and concentrate under vacuum. Separate and purify the crude product by column chromatography to obtain colorless oily liquid 8 (4.53 g, yield 81%). NMR characterization results: 1 H NMR (400 MHz, CDCl3): δ5.61 (td, J = 3.8, 1.9 Hz, 2H), 4.43 (d, J = 2.5 Hz, 2H), 4.17 (t, J = 6.9 Hz, 2H), 4.12 (dd, J = 5.9, 4.4 Hz, 2H), 4.06 (dd, J = 3.5, 1.5Hz, 2H), 3.77 (dd, J = 5.8, 4.3 Hz, 2H), 3.12 (dd, J = 4.4, 1.8 Hz, 2H), 2.64(t, J = 6.8 Hz, 2H), 2.61 (s, 4H), 2.47 (t, J = 2.4 Hz, 1H), 1.45 (s, 9H), 0.85 (s, 9H), 0.03 (s, 6H). In a 100 mL single-necked round-bottom flask, compound 8 (3.92 g, 7.0 mmol) was dissolved in water (20 mL) and tetrahydrofuran (20 mL), followed by the addition of acetic acid (60 mL). The reaction mixture was stirred at room temperature for 12 hours. After the reaction was complete, the solvent was removed under reduced pressure, and the residue was dissolved in ethyl acetate (30 mL). This organic layer was washed with a saturated sodium bicarbonate solution (3 × 20 mL) and brine (30 mL), dried over Na₂SO₄, and concentrated under vacuum to give a colorless oil. The above colorless oil (9.19 g, 20 mmol), EDC·HCl (5.75 g, 30 mmol), 4-dimethylaminopyridine (0.12 g, 1 mmol), and dichloromethane (70 mL) were added to a 250 mL round-bottom flask and stirred thoroughly to dissolve. Dissolve 2.02 g (20 mmol) of azideacetic acid in 80 mL of DCM and transfer it to a constant-pressure dropping funnel, then slowly add it dropwise into a round-bottom flask. After the addition is complete, continue the reaction for 12 hours. After the reaction is complete, wash the resulting solution once with 1 M HCl, once with saturated sodium bicarbonate solution, and once with saturated saline solution. Dry the solution in anhydrous Na₂SO₄, allow it to stand, filter it, and concentrate it under vacuum. Separate and purify the crude product by column chromatography to obtain a pale yellow oily liquid 9 (8.67 g, yield 82%). NMR characterization results: 1 H NMR (400 MHz, CDCl3)δ 5.61 (td, J = 3.8, 1.8 Hz, 2H), 4.42 (d, J= 2.4 Hz, 2H), 4.38 – 4.34 (m, 2H), 4.32 – 4.28 (m, 2H), 4.17 (t, J = 6.8 Hz,2H), 4.10 – 4.03 (m, 2H), 3.87 (s, 2H), 3.11 (dd, J = 4.4, 1.9 Hz, 2H), 2.62(d, J = 13.7 Hz, 6H), 2.47 (t, J = 2.4 Hz, 1H), 1.45 (s, 9H). Compound 9 (1.59 g, 3 mmol) and 300 mL of DCM were added to a 500 mL round-bottom flask and stirred thoroughly to dissolve. The solution was then degassed with nitrogen for 15 min. Tris[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]amine (TBTA, 63.7 mg, 0.12 mmol) and copper(I) tetraacetonitrile hexafluorophosphate (55.9 mg, 0.15 mmol) were added to the solution. The solution was degassed again with nitrogen, and the mixture was stirred at 55 °C for 36 h under nitrogen. The reaction mixture was cooled to room temperature, quenched with methanol, and then concentrated under vacuum. The crude product was separated and purified by column chromatography to give a pale yellow oily liquid 10 (1.24 g, 78% yield). NMR characterization results: 1 H NMR (400 MHz, CDCl3): δ 7.77 (s, 1H), 5.45 –5.26 (m, 2H), 5.07 (s, 2H), 4.85 (s, 2H), 4.23 (tt, J = 9.4, 7.6, 3.2 Hz,4H), 3.95 (t, J = 6.8 Hz, 2H), 3.82 (d, J = 5.9 Hz, 2H), 2.94 (d, J = 6.8 Hz, 2H), 2.46 (d, J = 12.9 Hz, 6H), 1.33 (s, 9H). Compound 10 (2.11 g, 4 mmol) and 30 mL of DCM were added to a 100 mL round-bottom flask and stirred thoroughly to dissolve. Trifluoroacetic acid (1.5 mL, 20 mmol) was slowly added dropwise at 0 °C. After the addition was complete, the mixture was stirred at room temperature for 36 hours. After the reaction was complete, the reaction was quenched with saturated sodium bicarbonate solution and extracted with DCM (3 × 40 mL). The combined organic phases were washed with saturated brine (30 mL), dried over anhydrous Na₂SO₄, allowed to stand, filtered, and concentrated under vacuum. A colorless oily liquid was obtained. The above colorless oily liquid (1.29 g, 3 mmol), triethylamine (2.1 mL, 15 mmol), and 30 mL of DCM were added to a 100 mL round-bottom flask and stirred thoroughly to dissolve. The mixture was stirred in an ice bath. Acryloyl chloride (1.2 mL, 15 mmol) was slowly added, and the mixture was stirred at room temperature for 15 hours. After the reaction was complete, the reaction was quenched with saturated sodium bicarbonate solution and extracted with DCM (3 × 40 mL). The combined organic phases were washed with saturated brine (30 mL), dried over anhydrous Na₂SO₄, allowed to stand, filtered, and concentrated under vacuum. The crude product was separated and purified by column chromatography to give a pale yellow oily liquid M2 (0.93 g, yield 64%). NMR characterization results: 1H NMR (400 MHz, CDCl3): δ 7.86 (s, 1H), 6.64 (dd, J =17.0, 10.4 Hz, 1H), 6.23 (dd, J = 17.1, 2.2 Hz, 1H), 5.61 (dd, J = 10.4, 2.1Hz, 1H), 5.49 (q, J = 6.2, 5.7 Hz, 2H), 5.10 (s, 2H), 4.91 (s, 2H), 4.26 (q,J = 6.1 Hz, 4H), 4.18 (d, J = 4.9 Hz, 2H), 3.98 (t, J = 6.7 Hz, 2H), 3.00 (d,J = 5.8 Hz, 2H), 2.48 (d, J = 13.6 Hz, 6H). 1.3 Preparation of allyl thiomacrocyclic monomer M3

[0040] Add 8.46 g (50 mmol) of 6-methoxy-1-indanone, 13.1 g (200 mmol) of zinc powder, and 120 mL of tetrahydrofuran to a 250 mL double-necked round-bottom flask and stir thoroughly. Purge the mixture three times with nitrogen, and slowly add titanium tetrachloride (11.0 mL, 100 mmol) dropwise under N2 atmosphere in an ice-water bath. After the addition is complete, reflux the reaction mixture for 24 hours. After the reaction is complete, quench the reaction with ice water, followed by quenching with saturated ammonium chloride. Extract the reaction solution with ethyl acetate (3 × 50 mL), wash the combined organic phases once with saturated brine, dry with anhydrous Na2SO4, allow to stand, filter, and concentrate under vacuum. Separate and purify the crude product by column chromatography to obtain a yellow solid 11 (4.82 g, yield 33%). NMR characterization results: 1 HNMR (400 MHz, CDCl3): δ 7.22 (d, J = 8.2 Hz, 2H), 7.17 (d, J = 2.4 Hz, 2H), 6.79 (dd, J = 8.2, 2.4 Hz, 2H), 3.86 (s, 6H), 3.22 – 3.16 (m, 4H), 3.09 –3.02 (m, 4H). Add 11 (2.92 g, 10 mmol) to a 250 mL double-necked round-bottom flask, purging three times with nitrogen. Under a N2 atmosphere, in an ice-water bath, slowly add methyl magnesium iodide (3 M in Et2O) (16.7 mL, 50 mmol) dropwise, stirring thoroughly. After the addition is complete, raise the temperature to 140 °C and react for 16 hours. After the reaction is complete, quench the reaction with saturated ammonium chloride. Extract the reaction solution with ethyl acetate (3 × 50 mL). Wash the combined organic phases once with saturated brine, dry with anhydrous Na2SO4, allow to stand, filter, and concentrate under vacuum. Separate and purify the crude product by column chromatography to obtain a yellow solid 12 (1.77 g, yield 67%). NMR characterization results: 1 H NMR (400 MHz, DMSO-d6): δ 9.20 (s, 2H), 7.13 (d, J = 8.1 Hz, 2H), 7.04 (d, J = 2.2 Hz, 2H), 6.66 (dd, J = 8.1, 2.1 Hz, 2H), 3.08 – 3.01(m, 4H),2.99 – 2.93 (m, 4H). Compound 12 (7.93 g, 30 mmol), potassium carbonate (16.6 g, 120 mmol), tetrabutylammonium iodide (33.24 g, 90 mmol), 6-bromohexanol (13.7 mL, 105 mmol), and DMF (220 mL) were added to a 500 mL round-bottom flask and stirred thoroughly to dissolve. The reaction mixture was refluxed and stirred for 15 hours. After the reaction was complete, the reaction mixture was poured into a large amount of water (250 mL) and extracted with ethyl acetate (3 × 100 mL). The organic phase was washed three times with saturated brine, dried over anhydrous Na₂SO₄, allowed to stand, filtered, and concentrated under vacuum. The crude product was separated and purified by column chromatography to give a white solid 13 (6.55 g, 47% yield). NMR characterization results: 1 H NMR (400 MHz, CDCl3): δ 7.19 (d, J = 8.2 Hz, 2H), 7.16 (d, J = 2.3 Hz, 2H), 6.77 (dd, J = 8.2, 2.3 Hz, 2H), 4.00 (t, J = 6.5 Hz, 4H), 3.67 (t, J = 6.6 Hz, 4H), 3.23 – 3.13 (m, 4H), 3.08 – 3.00 (m, 4H), 1.86 – 1.78 (m, 4H), 1.65 – 1.59 (m, 6H), 1.55 – 1.49 (m, 4H), 1.47 – 1.43 (m,2H). Compound 13 (9.29 g, 20 mmol), EDC·HCl (5.75 g, 30 mmol), 4-dimethylaminopyridine (0.12 g, 1 mmol), and dichloromethane (70 mL) were added to a 250 mL round-bottom flask and stirred thoroughly to dissolve. Azideacetic acid (2.02 g, 20 mmol) was dissolved in 80 mL of dichloromethane and transferred to a constant-pressure dropping funnel, then slowly added dropwise to the round-bottom flask. After the addition was complete, the reaction was continued for 12 hours. After the reaction was complete, the resulting solution was washed once with 1 M HCl, once with saturated sodium bicarbonate solution, and once with saturated brine. It was dried over anhydrous Na₂SO₄, allowed to stand, filtered, and concentrated under vacuum. The crude product was separated and purified by column chromatography to obtain a pale yellow oily liquid 14 (4.49 g, yield 41%). NMR characterization results: 1 H NMR (400 MHz, CDCl3): δ 7.20 (d, J = 8.2 Hz, 2H), 7.16 (d, J = 2.3 Hz, 2H), 6.77 (dt, J = 8.4, 2.1 Hz, 2H), 4.23 (t, J = 6.6 Hz, 2H), 4.00 (t, J =6.4 Hz, 4H), 3.87 (s, 2H), 3.67 (t, J = 6.6 Hz, 2H), 3.22 – 3.14 (m, 4H), 3.05 (dd, J = 8.5, 4.4 Hz, 4H), 1.82 (p, J = 6.7 Hz, 4H), 1.73 (p, J = 6.9Hz, 2H), 1.63 (q, J = 7.0 Hz, 2H), 1.57 – 1.50 (m, 5H), 1.47 (dt, J = 6.4,3.2 Hz, 3H). In a 100 mL single-necked round-bottom flask, 14 (8.22 g, 15 mmol), succinic anhydride (1.8 g, 18 mmol), 4-(dimethylamino)pyridine (DMAP, 2.75 g, 22.5 mmol), and dichloromethane (60 mL) were added and stirred to dissolve. The mixture was stirred at room temperature for 12 hours. After the reaction was complete, the resulting solution was washed once with 1 M HCl and twice with saturated brine, dried over anhydrous Na₂SO₄, allowed to stand, filtered, and concentrated under vacuum to obtain a yellow solid. The above yellow solid (6.30 g, 10 mmol) and 100 mL of DCM were added to a 250 mL round-bottom flask and stirred thoroughly to dissolve. Then, EDC·HCl (2.88 g, 15 mmol) and DMAP (0.06 g, 0.5 mmol) were added and stirred to dissolve. Finally, 3 (3.62 g, 12 mmol) was added to the mixture, and the mixture was reacted at room temperature for 15 hours. TLC detection was performed. After the reaction was complete, 100 mL of DCM was added to the reaction solution for dilution. The resulting solution was washed once with 1 M HCl, once with saturated sodium bicarbonate solution, and once with saturated saline solution. The solution was dried over anhydrous Na₂SO₄, allowed to stand, filtered, and concentrated under vacuum. The crude product was separated and purified by column chromatography to obtain 15 g (4.93 g, yield 53%) of a yellow oily liquid. NMR characterization results: 1 H NMR (400 MHz, CDCl3): δ 7.17 (d, J = 8.2 Hz, 2H), 7.12 (d, J = 1.7 Hz, 2H), 6.74 (dd, J = 8.3, 2.2 Hz, 2H), 5.68 – 5.59(m, 2H), 4.45 (d, J = 2.4 Hz, 2H), 4.19 (td, J = 6.8, 2.1 Hz, 4H), 4.11 –4.07 (m, 4H), 3.97 (t, J = 6.4 Hz, 4H), 3.84 (s, 2H), 3.14 (tt, J = 4.3, 2.4Hz, 6H), 3.05 – 2.98 (m, 4H), 2.66 (t, J = 6.9 Hz, 2H), 2.62 (s, 4H), 2.49(t, J = 2.4 Hz, 1H), 1.83 – 1.75 (m, 4H), 1.72 – 1.64 (m, 4H), 1.56 – 1.49(m, 4H), 1.46 – 1.39 (m, 4H). Compound 15 (2.79 g, 3 mmol) and 400 mL of DCM were added to a 500 mL round-bottom flask and stirred thoroughly to dissolve. The solution was then degassed with nitrogen for 15 minutes. Tris[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]amine (TBTA, 63.7 mg, 0.12 mmol) and copper(I) tetraacetonitrile hexafluorophosphate (55.9 mg, 0.15 mmol) were added to the solution. The solution was again degassed with nitrogen, and the mixture was stirred at 55 °C for 36 hours under nitrogen. The reaction mixture was cooled to room temperature, quenched with methanol, and then concentrated under vacuum. The crude product was purified by column chromatography to give a yellow liquid 16 (0.89 g, 32% yield). NMR characterization results: 1 H NMR (400 MHz, CDCl3): δ 7.60 (s, 1H), 7.12 (d, J =8.3, 4.4 Hz, 2H), 7.07 (d, J = 4.7, 2.3 Hz, 2H), 6.70 (dd, J = 8.3, 2.2 Hz, 2H), 5.47 (td, J = 6.2, 5.1, 3.1 Hz, 2H), 4.97 (d, J = 11.7 Hz, 2H), 4.85 (s,2H), 4.12 (t, J = 6.3 Hz, 2H), 4.03 (t, J = 6.5 Hz, 4H), 3.96 (t, J = 6.3 Hz,4H), 3.82 (d, J = 4.3 Hz, 2H), 3.12 – 3.05 (m, 4H), 2.96 (dq, J = 9.2, 5.1,3.9 Hz, 6H), 2.53 (dd, J = 9.8, 3.0 Hz, 2H), 2.48 (s, 4H), 1.77 – 1.67 (m,4H), 1.62 – 1.55 (m, 4H), 1.48 – 1.43 (m, 4H), 1.39 (s, 9H), 1.36 – 1.30 (m, 4H). Compound 16 (3.72 g, 4 mmol) and 30 mL of DCM were added to a 100 mL round-bottom flask and stirred thoroughly to dissolve. Trifluoroacetic acid (1.3 mL, 20 mmol) was slowly added dropwise at 0 °C. After the addition was complete, the mixture was stirred at room temperature for 12 hours. After the reaction was complete, the reaction was quenched with saturated sodium bicarbonate solution and extracted with DCM (3 × 40 mL). The combined organic phases were washed with saturated brine (30 mL), dried over anhydrous Na₂SO₄, allowed to stand, filtered, and concentrated under vacuum. A yellow oily liquid was obtained. The above colorless oily liquid (2.49 g, 3 mmol), triethylamine (2.1 mL, 15 mmol), and 30 mL of DCM were added to a 100 mL round-bottom flask and stirred thoroughly to dissolve. The mixture was stirred in an ice bath. Acryloyl chloride (1.2 mL, 15 mmol) was slowly added, and the mixture was stirred at room temperature for 15 hours. After the reaction was complete, the reaction was quenched with saturated sodium bicarbonate solution and extracted with DCM (3 × 40 mL). The combined organic phases were washed with saturated brine (30 mL), dried over anhydrous Na₂SO₄, allowed to stand, filtered, and concentrated under vacuum. The crude product was separated and purified by column chromatography to give a white solid M3 (1.18 g, 45% yield). NMR characterization results: 1 H NMR (400 MHz, CDCl3): δ 7.59 (s, 1H), 7.23 – 7.15 (m, 2H), 7.17 – 7.09 (m, 2H), 6.77 (dd, J = 8.1, 2.2 Hz, 2H), 6.62 (dd, J = 16.9, 10.3Hz, 1H), 6.39 – 6.29 (m, 1H), 5.66 (dt, J = 10.3, 1.6 Hz, 1H), 5.64 – 5.49(m, 2H), 5.01 (s, 2H), 4.89 (s, 2H), 4.20 (q, J = 5.8, 4.2 Hz, 4H), 4.10 (tt,J = 6.6, 3.6 Hz, 4H), 4.03 (q, J = 5.8 Hz, 4H), 3.15 (t, J = 6.3 Hz, 4H), 3.07 (d, J = 6.0 Hz, 2H), 3.02 (dd, J = 8.5, 4.4 Hz, 4H), 2.59 – 2.57 (m,2H), 2.55 (s, 4H), 1.86 – 1.72 (m, 4H), 1.69 – 1.62 (m, 4H), 1.57 – 1.46 (m,4H), 1.44 – 1.37 (m, 4H). Example 2 Experimental methods: This embodiment provides an experimental method for free radical reversible deactivation polymerization of allyl sulfide macrocyclic monomers and vinyl monomers as comonomers. The specific method is as follows: In a 10 mL Schlenk reaction tube, add allyl sulfide macrocyclic monomers M1, M2, or M3 (0.012 mmol), vinyl monomers M4, M5, M6, M7, M8, or M9 (0.6 mmol), chain transfer agents CTA1, CTA2, CTA3, CTA4, or CTA5 (0.003 mmol), photosensitizer Eosin Y (0.00003 mmol), and organic solvent N,N-dimethylformamide (DMF). The reaction is purged with nitrogen three times, followed by reaction under 450 nm blue light and a nitrogen atmosphere. After the reaction is complete, add a small amount of dichloromethane, then methanol and water (4:1, volume ratio) or diethyl ether to precipitate the polymer. Repeat this process twice. After vacuum drying, the corresponding polymers P1, P2, P3, P4, or P5 are obtained and characterized by GPC.

[0041] 2.1 Preparation of polymer P1 Following the experimental method for the polymerization reaction described above, using M1 (0.012 mmol), M4 (0.6 mmol), CTA2 (0.003 mmol), and Eosin Y (0.00003 mmol) as reactants, the reaction was carried out at room temperature under 450 nm blue light irradiation for 3 hours to obtain polymer P1 (M1 conversion rate 82%, M4 conversion rate 61%, number average molecular weight...). M n=23800, Ð =1.09).

[0042]

[0043] P1 2.2 Preparation of polymer P2 Following the experimental method described above for polymerization, using M1 (0.012 mmol), M5 (0.6 mmol), CTA2 (0.003 mmol), and Eosin Y (0.00003 mmol) as reactants, the reaction was carried out at room temperature under 450 nm blue light irradiation for 3 h to obtain polymer P2 (M1 conversion rate 77%, M5 conversion rate 34%). M n=10200, Ð =1.09).

[0044]

[0045] P2 2.3 Preparation of Polymer P3 Following the experimental method described above for polymerization, using M2 (0.012 mmol), M4 (0.6 mmol), CTA2 (0.003 mmol), and Eosin Y (0.00003 mmol) as reactants, the reaction was carried out at room temperature under 450 nm blue light irradiation for 3 h to obtain polymer P3 (M2 conversion rate 39%, M4 conversion rate 35%). M n=12300, Ð =1.11).

[0046]

[0047] P3 2.4 Preparation of Polymer P4 Following the experimental method described above for polymerization, using M2 (0.012 mmol), M7 (0.6 mmol), CTA2 (0.003 mmol), and Eosin Y (0.00003 mmol) as reactants, the reaction was carried out at room temperature under 450 nm blue light irradiation for 3 h to obtain polymer P4 (M2 conversion rate 10%, M7 conversion rate 45%). M n=5900, Ð =1.08).

[0048]

[0049] P4 2.5 Preparation of Polymer P5 Following the experimental method described above for polymerization, using M3 (0.012 mmol), M5 (0.6 mmol), CTA2 (0.003 mmol), and Eosin Y (0.00003 mmol) as reactants, the reaction was carried out at room temperature under 450 nm blue light irradiation for 3 h to obtain polymer P5 (M3 conversion rate 55%, M5 conversion rate 38%). M n=11400, Ð =1.32).

[0050]

[0051] P5 Example 3 This embodiment optimizes the conditions for the free radical reversible deactivation copolymerization reaction of the allyl thiomacrocyclic monomer and the vinyl monomer of Example 2.

[0052] 3.1 Optimization of Chain Transfer Agent Types Specific experimental methods: Controlled free radical ring-opening copolymerization of allyl sulfide macrocyclic monomer M1 and vinyl monomer M4 was carried out according to the copolymerization reaction in Example 2, Section 2.1. The reaction time was 12 h. The selected chain transfer agents were CTA1, CTA2, CTA3, CTA4, and CTA5. The final bulk conversion rates, polymer molecular weights, and molecular weight distributions of M1 and M4 are shown in Table 1 and [Table data missing]. Figure 1 As shown in Table 1. The GPC assay uses tetrahydrofuran as the mobile phase and polystyrene as the standard. Figure 1 It can be seen that the polymerization reaction can be well controlled when CTA2 is used as a chain transfer agent, producing a polymer with an actual number average molecular weight of 29,800, a dispersion of 1.11, and the narrowest molecular weight distribution.

[0053] Table 1

[0054] 3.2 Optimization of Organic Solvent Types Specific experimental methods: Following the copolymerization reaction described in Example 2.1, controlled radical ring-opening copolymerization was performed on allyl thiocyanate macrocyclic monomer M1 and vinyl monomer M4 as comonomers. The reaction time was 12 h. DMF, DMSO, Dioxane, THF, and Toluene were used as organic solvents for each reaction group, respectively. The final monomer conversion rates, polymer molecular weights, and molecular weight distributions of M1 and M4 are shown in Table 2 and... Figure 2 As shown in Table 2. The GPC assay uses tetrahydrofuran as the mobile phase and polystyrene as the standard. Figure 2 It can be seen that the reaction effect is best when DMF is used as the organic solvent, followed by Dioxane. The reaction effect is relatively poor when THF is used as the organic solvent, which may be due to the poor solubility of the polymer.

[0055] Table 2

[0056] 3.3 Optimization of photosensitizer concentration Specific experimental methods: Following the copolymerization reaction described in Example 2.1, controlled free radical ring-opening copolymerization was performed using allyl sulfide macrocyclic monomer M1 and vinyl monomer M4 as comonomers. The reaction time was 3 h, and the photosensitizer concentrations for each group were 50 ppm, 100 ppm, and 200 ppm, respectively. The final monomer conversion rates of M1 and M4, polymer molecular weight, and molecular weight distribution are shown in Table 3 and... Figure 3 As shown in Table 3. GPC determination uses tetrahydrofuran as the mobile phase and polystyrene as the standard. Figure 3 It can be seen that the reaction effect is best when the photosensitizer concentration is 100 ppm.

[0057] Table 3

[0058] 3.4 Optimization of Vinyl Monomers Specific experimental method: Following the copolymerization reaction described in Example 2, Section 2.1, controlled radical ring-opening copolymerization was performed on allyl sulfide macrocyclic monomer M1 with different vinyl monomers as comonomers. The reaction time was 3 h, and the vinyl monomers used in each group were M4, M5, M6, M7, M8, or M9, respectively. The final conversion rates, polymer molecular weights, and molecular weight distributions of M1 with different vinyl monomers are shown in Table 4 and... Figure 4 As shown in Table 4. The GPC assay used tetrahydrofuran as the mobile phase and polystyrene as the standard. Figure 4 It can be seen that the reaction effect is best when the vinyl monomer is co-M4.

[0059] Table 4

[0060] Example 4 In this embodiment, polymers of different molecular weights were prepared by free radical reversible deactivation copolymerization of the allyl thiomacrocyclic monomer and vinyl monomer from Example 2.

[0061] 4.1 Preparation of P1 with different molecular weights Specific experimental methods: Following the copolymerization reaction described in Example 2.1, a controlled free radical ring-opening copolymerization reaction was carried out using allyl sulfide macrocyclic monomer M1 and vinyl monomer M4 as comonomers. The reaction time was 3 h. The molar ratio of vinyl monomer M4 / chain transfer agent was selected as 100 / 1, 200 / 1, and 400 / 1. The final conversion rates of M1 and M4 monomers, polymer molecular weight, and molecular weight distribution are shown in the table. GPC determination used tetrahydrofuran as the mobile phase and polystyrene as the standard. Table 5 shows that by adjusting the ratio of vinyl monomer M4 / chain transfer agent, polymers P1 with molecular weights ranging from 8.7 thousand to 386,000 can be prepared, with a molecular weight distribution primarily within the range of 1.06 to 1.08.

[0062] Table 5

[0063] 4.2 Preparation of P3 with different molecular weights Specific experimental methods: Following the copolymerization reaction described in Example 2.2, a controlled free radical ring-opening copolymerization reaction was carried out using allyl sulfide macrocyclic monomer M2 and vinyl monomer M4 as comonomers. The reaction time was 3 h. The molar ratio of vinyl monomer M4 / chain transfer agent was selected as 100 / 1, 200 / 1, and 400 / 1. The final conversion rates of M2 and M4 monomers, polymer molecular weight, and molecular weight distribution are shown in the table. GPC determination used tetrahydrofuran as the mobile phase and polystyrene as the standard. As shown in Table 6, by adjusting the ratio of vinyl monomer M4 / chain transfer agent, polymers P3 with molecular weights ranging from 10,000 to 396,000 can be prepared, with a molecular weight distribution generally within the range of 1.08 to 1.15.

[0064] Table 6

[0065] 4.3 Preparation of P5 with different molecular weights Specific experimental methods: Following the copolymerization reaction described in Example 2.5, a controlled free radical ring-opening copolymerization reaction was carried out using allyl sulfide macrocyclic monomer M3 and vinyl monomer M5 as comonomers. The reaction time was 3 h. The molar ratio of vinyl monomer M5 to chain transfer agent was selected as 100 / 1, 200 / 1, and 400 / 1. The final conversion rates of M3 and M5 monomers, polymer molecular weight, and molecular weight distribution are shown in the table. GPC determination used tetrahydrofuran as the mobile phase and polystyrene as the standard. As shown in Table 7, by adjusting the ratio of vinyl monomer M5 to chain transfer agent, polymers P3 with molecular weights ranging from 7.3 thousand to 396,000 can be prepared, with a molecular weight distribution generally within the range of 1.13 to 1.26.

[0066] Table 7

[0067] Example 5 This embodiment studies the kinetics of the free radical reversible deactivation copolymerization reaction of the allyl thiomacrocyclic monomer and vinyl monomer of Example 2 and prepares the block copolymer.

[0068] 5.1 Dynamics Study The copolymerization reaction in Example 2.1 was monitored using 1H NMR spectroscopy. Samples were taken at reaction times of 1.33 h, 2 h, 3 h, 5 h, and 6 h for 1H NMR spectroscopy to calculate the conversion rate, and GPC spectroscopy was performed to calculate the molecular weight and dispersion of the polymer. The final experimental results are as follows: Figure 5 and Figure 6 As shown. By Figure 5 It can be seen that polymerization reactions exhibit first-order kinetics. From Figure 6It can be seen that the polymer molecular weight has a linear relationship with the monomer conversion rate, and the dispersion is basically maintained below 1.2. Based on the above experimental results, this copolymerization reaction is a controlled polymerization reaction.

[0069] 5.2 Preparation of Block Copolymers The block copolymer was obtained by undergoing a free radical ring-opening copolymerization reaction of polymer P4 containing photoresponsive groups in the main chain, allyl thiomacyclomonomer M1, vinyl monomer M5, chain transfer agent CTA2, photosensitizer Eosin Y, and organic solvent DMF. Specific experimental method: Referring to the copolymerization reaction in Example 2, section 2.4, a controlled free radical ring-opening copolymerization reaction was first carried out on allyl sulfide macrocyclic monomer M2 and vinyl monomer M7 to prepare a macromolecular initiator P4 with a suitable molecular weight. Then, using allyl sulfide macrocyclic monomer M1, vinyl monomer M5, chain transfer agent CTA2, and in the presence of photosensitizer Eosin Y and organic solvent DMF, chain extension was carried out through free radical ring-opening copolymerization, referring to the experimental method in Example 2. The final experimental results are as follows. Figure 7 As shown. By Figure 7 The GPC characterization results show that, compared to the first block polymer P4 ( M n=5900, Ð =1.08), the resulting diblock copolymer P4- b -P2 ( M n=61500, Ð The GPC curve for P4-block copolymers (p=1.54) showed a significant shift towards higher molecular weights. b -P2 means that P4 is synthesized first, and then combined with allyl thiomacrocyclic monomer M1 and vinyl monomer M5 to form a P4 and P2 block copolymer, in which b It is a block.

[0070] Experimental results show that this polymerization method has significant application prospects in the synthesis of multi-block polymers. By changing the chemical composition, block ratio, molecular weight, and sequence period of the blocks, the size, morphology, and properties of the materials can be precisely designed, thereby customizing materials with desired optical, electrical, mechanical, and surface properties. Different block sequences can endow materials with drastically different properties and achieve ordered combinations, creating comprehensive properties that cannot be achieved with a single homopolymer. This periodic block structure containing photoresponsive groups endows the materials with unique physical, chemical, and functional properties.

[0071]

[0072] P4- b -P2 Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a polymer with photoresponsive groups in its main chain, characterized in that, Using allyl thiomacrocyclic monomers and vinyl monomers as comonomers, and trithiocarbonate as a chain transfer agent, polymerization was achieved through free radical ring-opening copolymerization in the presence of photosensitizers and organic solvents, directly embedding photoresponsive group sequence units into the polymer backbone to obtain a polymer with photoresponsive groups in the backbone. The allyl thio macrocyclic monomer includes at least one of M1, M2, or M3: 、 、 ； The vinyl monomer includes at least one of M4, M5, M6, M7, M8, or M9: 、 、 、 、 、 。 2. The method for preparing a polymer with photoresponsive groups in its main chain according to claim 1, characterized in that, The chain transfer agent includes one of CTA1, CTA2, CTA3, CTA4, or CTA5: 、 、 、 、 。 3. The method for preparing a polymer with photoresponsive groups in its main chain according to claim 1, characterized in that, The number-average molecular weight of the polymer containing photoresponsive groups in the main chain is 0.32 million to 3.96 million.

4. The method for preparing a polymer with photoresponsive groups in its main chain according to claim 1, characterized in that, The dispersion of the polymer containing photoresponsive groups in the main chain is 1.05~1.

54.

5. The method for preparing a polymer with photoresponsive groups in its main chain according to claim 1, characterized in that, The molar ratio of the vinyl monomer, allyl thiomacyclomonomer, and chain transfer agent is 100:2:1 to 400:8:

1.

6. The method for preparing a polymer with photoresponsive groups in its main chain according to claim 1, characterized in that, The photosensitizer is Eosin Y, with a concentration of 50 ppm to 200 ppm.

7. The method for preparing a polymer with photoresponsive groups in its main chain according to claim 1, characterized in that, The organic solvent is selected from one or more of N,N-dimethylformamide, dimethyl sulfoxide, dioxane, tetrahydrofuran, or toluene.

8. The method for preparing a polymer with photoresponsive groups in its main chain according to claim 1, characterized in that, The reaction time for the free radical ring-opening copolymerization is 3-12 h.

9. A polymer with a main chain containing photoresponsive groups prepared by the preparation method according to any one of claims 1-8, characterized in that, The general structural formula is as follows: ； Among them, R 1 Groups with any of the following structures: 、 、 ， Among them, R 2 Groups with any of the following structures: 、 、 、 、 、 Where --- represents the connecting chemical bond; where n / m is 10~100, n represents the degree of polymerization of M1, M2 or M3, and m represents the degree of polymerization of M4, M5, M6, M7, M8 or M9.

10. A method for preparing a block copolymer, characterized in that, Block copolymers are obtained by free radical ring-opening copolymerization of the polymer with photoresponsive groups in the main chain as described in claim 9, allyl thio macrocyclic monomers, vinyl monomers, and chain transfer agents in the presence of photosensitizers and organic solvents. The allyl thio macrocyclic monomer includes at least one of M1, M2 or M3; The vinyl monomer includes at least one of M4, M5, M6, M7, M8 or M9; Chain transfer agents include one of CTA1, CTA2, CTA3, CTA4, or CTA5; The photosensitizer is Eosin Y; The organic solvent is selected from one or more of N,N-dimethylformamide, dimethyl sulfoxide, dioxane, tetrahydrofuran, or toluene.

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