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CN-116554420-B - Double-responsiveness CABC type asymmetric block copolymer and synthesis method thereof

CN116554420BCN 116554420 BCN116554420 BCN 116554420BCN-116554420-B

Abstract

The invention discloses a CO 2 /photo double-responsive CABC type asymmetric block copolymer and a synthesis method thereof, wherein the copolymer is prepared by converting a bromine initiator containing double initiation sites into in-situ bromine and iodine to generate a macromolecular initiator with carbon-iodine bond active sites at both ends, photoinitiating a monomer A with hydrophobicity through carbon-iodine bonds on the macromolecular initiator, photoinitiating a photo-responsive monomer B with hydrophobicity and fluorescence by utilizing carbon-iodine bonds at both ends of the obtained polymer, and simultaneously thermally initiating and polymerizing a CO 2 responsive monomer C with hydrophilicity by utilizing carbon-iodine bonds at both ends and an intermediate azo group. The invention synthesizes the CO 2 /photo-double-responsive CABC asymmetric block copolymer based on a photopolymerization-thermal polymerization three-step method constructed by a reversible complexation mediated polymerization technology, and the copolymer can be further prepared into CO 2 /photo-double-responsive polymer vesicles, thereby providing thinking and support for the research of CO 2 sensing nano devices.

Inventors

  • XIAO LONGQIANG
  • HOU LINXI
  • YIN XIANGYU
  • CAI JINGYU
  • ZHAO YULAI

Assignees

  • 福州大学
  • 清源创新实验室

Dates

Publication Date
20260505
Application Date
20230526

Claims (6)

  1. 1. A method for synthesizing a CO 2 /photo-double-responsiveness CABC type asymmetric block copolymer is characterized in that a bromine initiator containing double initiation sites is synthesized firstly, then the bromine initiator containing double initiation sites is subjected to in-situ bromine-iodine conversion to generate a macromolecular initiator with carbon-iodine bond active sites at both ends, a carbon-iodine bond on the macromolecular initiator is utilized to photo-initiate polymerization of a monomer A, then the carbon-iodine bond at both ends of the obtained polymer is utilized to photo-initiate chain extension polymerization of a photo-responsiveness monomer B, and then the carbon-iodine bond at both ends of the obtained polymer and an intermediate azo group are utilized to simultaneously thermally initiate polymerization of a CO 2 responsiveness monomer C, so that the CO 2 /photo-double-responsiveness CABC type asymmetric block copolymer is obtained, and the method specifically comprises the following steps: (1) Uniformly mixing 4,4 '-azobis (4-cyanoamyl alcohol), alpha-bromophenylacetic acid and 4-dimethylaminopyridine in dichloromethane, adding N, N' -dicyclohexylcarbodiimide dissolved in the dichloromethane at 0 ℃, stirring for 1h, transferring a reaction system to normal temperature, continuously stirring for reaction for 24h, filtering after the reaction is finished, concentrating the obtained filtrate by rotary evaporation, and purifying by silica gel column chromatography to obtain a bromine initiator Br-EPhAzo-Br containing double initiation sites; (2) Sequentially adding a monomer A, a bromine initiator Br-EPhAzo-Br containing double initiation sites, sodium iodide and pentamethyl diethylenetriamine obtained in the step (1) into a glass bottle, sealing the bottle mouth by using a rubber plug, removing redundant air, then irradiating with a white LED lamp under a stirring condition for reaction, precipitating a reacted sample in N-hexane, and drying in vacuum to obtain a macromolecular initiator I-PMMA-N=N-PMMA-I; (3) Sequentially adding a photo-responsive monomer B, a macromolecular initiator I-PMMA-N=N-PMMA-I obtained in the step (2), an iodine simple substance, pentamethyldiethylenetriamine and toluene into a glass bottle, sealing the bottle mouth by using a rubber plug, removing redundant air, then irradiating with a white LED lamp under a stirring condition for reaction, precipitating a reacted sample in petroleum ether, washing with diethyl ether, and then drying in vacuum to obtain a macromolecular initiator I-PCMMA-B-PMMA-N=N-PMMA-B-PCMMA-I; (4) Adding a CO 2 responsive monomer C, a macromolecular initiator I-PCMMA-b-PMMA-N=N-PMMA-b-PCMMA-I obtained in the step (3), an iodine simple substance, tetrabutylammonium iodide and toluene into a Schlenk tube in sequence, carrying out polymerization reaction at a certain temperature after three deoxidization cycles of liquid nitrogen freezing-air extraction-thawing, precipitating a reacted sample in petroleum ether, washing with diethyl ether, and then carrying out vacuum drying to obtain a target product I-PDMAEMA-b-PMMA-b-PCMMA-b-PDMAEMA-I; Wherein the monomer A is methyl methacrylate, the CO 2 responsive monomer C is dimethylaminoethyl methacrylate, and the light responsive monomer B is specifically coumarin-based light responsive monomer, and the structural formula is as follows: 。
  2. 2. The method for synthesizing a CO 2 /light dual-responsive CABC type asymmetric block copolymer according to claim 1, wherein the molar ratio of 4,4 '-azobis (4-cyanopentanol), alpha-bromophenylacetic acid, 4-dimethylaminopyridine and N, N' -dicyclohexylcarbodiimide used in the step (1) is 1:2.2:0.19:2.4; The silica gel column chromatography purification adopts a dichloromethane/normal hexane mixed solution with the volume ratio of 4:1 as an eluent.
  3. 3. The method for synthesizing the CO 2 /light dual-responsive CABC type asymmetric block copolymer according to claim 1, wherein the molar ratio of the monomer A, the bromine initiator Br-EPhAzo-Br containing dual initiation sites, sodium iodide and pentamethyldiethylenetriamine used in the step (2) is 100:1:2.4:0.5; The irradiation was performed at a power of 13 Wm -1 , an intensity of 15 mW cm -2 , and a reaction time of 120 minutes.
  4. 4. The method for synthesizing the CO 2 /photo-double-responsive CABC type asymmetric block copolymer according to claim 1, wherein the molar ratio of the photo-responsive monomer B, the macroinitiator I-PMMA-N=N-PMMA-I, the iodine simple substance and the pentamethyldiethylenetriamine used in the step (3) is 60:1:1:0.5; The irradiation was performed at a power of 13 Wm -1 , an intensity of 15 mW cm -2 , and a reaction time of 180 minutes.
  5. 5. The method for synthesizing the CO 2 /light dual-responsive CABC type asymmetric block copolymer according to claim 1, wherein the molar ratio of the CO 2 responsive monomer C, the macroinitiator I-PBzMA-b-PMMA-N=N-PMMA-b-PBzMA-I, the elemental iodine and tetrabutylammonium iodide used in the step (4) is 800:1:1:4; The temperature of the polymerization reaction was 90 ℃ for 60min.
  6. 6. The method for synthesizing a CO 2 /photo-double-responsive CABC type asymmetric block copolymer according to claim 1, wherein the step of synthesizing the photo-responsive monomer B comprises the steps of: a) Mixing 0.529 g of 7-hydroxy-4-methylcoumarin, 10mL, 16.8 g/L potassium hydroxide solution, 0.05 g polyethylene glycol and 40mL THF, performing ultrasonic dispersion for 20min, and deoxidizing with high-purity nitrogen in ice water bath for 20min; b) Injecting 1.41 mL methacrylic chloride into the mixture obtained in the step a), stirring for 2.5 hours at 0 ℃, adding the mixture into deionized water for precipitation, and filtering to remove redundant impurities; c) And then washing with 40 g/L sodium hydroxide solution and saturated sodium chloride solution successively, and drying in vacuum to obtain the coumarin-based photoresponsive monomer.

Description

Double-responsiveness CABC type asymmetric block copolymer and synthesis method thereof Technical Field The invention belongs to the field of nano material preparation, and particularly relates to a CO 2/photo-double-responsive CABC asymmetric block copolymer, a preparation method thereof and a CO 2/photo-double-responsive polymer vesicle self-assembled by using the same. Background The stimulus-responsive block copolymer is also called an environment-responsive block copolymer, and refers to a polymer which can change correspondingly under certain external stimulus. Such stimulus response changes are nonlinear and generally involve changes in molecular configuration, changes in molecular solubility, and formation or cleavage of chemical bonds. External stimuli include physical stimuli, chemical stimuli, and biochemical stimuli, such as CO 2, light, pH, and the like. The stimulus-responsive block copolymer is classified into CO 2 -responsive block copolymer, photo-responsive block copolymer, pH-responsive block copolymer, and the like according to the external stimulus factor. However, in the previous study, single CO 2 -responsive nano-devices were often limited to responses on a microscopic scale, and no macroscopic response effect could be demonstrated. The CABC type asymmetric block copolymer is an interesting block copolymer, which can produce non-centrosymmetric nano-structures through self-assembly, and has different properties from the common block copolymer. At present, almost all block copolymers are synthesized by controlled polymerization methods, mainly comprising anionic polymerization, controlled radical polymerization and group transfer polymerization. Among the controllable polymerization technologies, the controllable free radical polymerization is the industrial production technology with the most development prospect due to the wide monomer range and mild condition, and has a larger practical significance. By utilizing the advantages of simple operation, energy saving, controllable polymer polydispersity (Mw/Mn) time-space and strong tolerance to functional groups of reversible complexation mediated free radical polymerization (RCMP), the CO 2 stimulus responsive monomer and the light stimulus responsive monomer are simultaneously introduced into the CABC type asymmetric block copolymer, a polymer with CO 2 response and light response functions can be obtained, and then the CO 2/light double-response nano vesicle is obtained by self-assembly. Disclosure of Invention The invention aims to provide a CO 2/photo-double-responsive CABC type asymmetric block copolymer, a preparation method thereof and a CO 2/photo-double-responsive polymer vesicle self-assembled by using the same. In order to achieve the above purpose, the invention adopts the following technical scheme: A CO 2/photo-double-responsive CABC-type asymmetric block copolymer whose block constituent monomers comprise: (1) A monomer A having hydrophobicity; (2) A light-responsive monomer B having hydrophobicity and fluorescence; (3) A CO 2 responsive monomer C having hydrophilic properties. Wherein the monomer A is Methyl Methacrylate (MMA) and the CO 2 responsive monomer C is dimethylaminoethyl methacrylate (DMAEMA). The light responsive monomer B is specifically coumarin-based light responsive monomer (CMMA), and the synthetic route is as follows: the synthesis steps comprise: a) Mixing 0.529 g of 7-hydroxy-4-methylcoumarin, 10 mL, 16.8 g/L potassium hydroxide solution, 0.05 g polyethylene glycol and 40 mL Tetrahydrofuran (THF), performing ultrasonic dispersion for 20min, and deoxidizing in an ice water bath with high-purity nitrogen for 20min; b) Injecting 1.41 mL methacrylic chloride into the mixture obtained in the step a), stirring for 2.5 hours at 0 ℃, adding the mixture into deionized water for precipitation, and filtering to remove redundant impurities; c) And then washing with 40 g/L sodium hydroxide solution and saturated sodium chloride solution successively, and drying in vacuum to obtain the coumarin-based photoresponsive monomer. The fluorescence intensity of the coumarin-based light-responsive monomer can be changed along with the microscopic scale change of the nano device due to the polymerization induction mechanism, and the characteristic can provide assistance for the visualization of the CO 2 responsiveness of the nano device. The preparation method of the CO 2/photo-double-responsiveness CABC type asymmetric block copolymer comprises the steps of firstly synthesizing a bromine initiator containing double initiation sites, then carrying out in-situ bromine-iodine conversion on the bromine initiator containing double initiation sites to generate a macromolecular initiator with carbon-iodine bond active sites at both ends, photo-initiating a polymerization monomer MMA through carbon-iodine bonds on the macromolecular initiator, photo-initiating a chain-extending polymerization photo-responsiveness monomer CMMA by