1. A method of synthesizing a block copolymer brush using microfluidics, comprising the steps of:

preparing a polymerization monomer and a catalyst for preparing the block copolymer brush into a solution, and placing the solution in a liquid storage tank of a syringe pump;

connecting a corresponding number of microreactors in series according to the number of blocks of the block copolymer brush, connecting an injection pump with a catalyst solution with an inlet of a first microreactor, and connecting the injection pump with a corresponding polymerization monomer solution with inlets of the microreactors in a corresponding sequence according to a block sequence;

setting flow speed and flow speed ratio according to the polymerization degree and the block proportion of the block copolymer brush;

and collecting the solution of the block copolymer brush at the outlet of the last microreactor, and removing the solvent to obtain the block copolymer brush.

2. The method of claim 1, wherein the microreactor has at least two inlets and one outlet.

3. The method of claim 2, wherein the microreactors are connected in series such that the outlet of a previous microreactor is connected to the inlet of a next microreactor and the other inlet of the next microreactor is the inlet for monomer.

4. The method of claim 1, wherein the microreactor comprises a circular tube and a microchip reactor.

5. The method of claim 1, wherein the microreactor has a channel inside diameter of 10-1000 μm.

6. The method for synthesizing a block copolymer brush by microfluidics according to claim 1, wherein an injection speed of the injection pump is 0.005 to 50 mL/min.

7. The method of claim 1, wherein the block copolymer brush topology is a bottle brush type.

8. The method for synthesizing a block copolymer brush by microfluidics according to claim 1, wherein the polymerized monomer is a cyclic olefin polymerized monomer having a molecular weight of 500-.

9. The method of claim 1, wherein the polymerized monomer solution has a concentration of 1 to 1500 mmol/L.

Background

In recent years, the field of synthetic polymers is rapidly expanding in view of the structural and functional diversity of polymers, and various polymers having complicated structures and functions are being developed. The progress of the controllable synthesis technology realizes the preparation of various topological macromolecules, such as star-shaped, hyperbranched, brush-shaped polymers and the like. In 2009, the first successful preparation of molecular brush block polymers was performed by professor Rzayev, university of Bufarlo, New York State, USA, and by professor Grubbs, California, by controlled radical polymerization and living ring-opening metathesis polymerization, respectively.

The molecular brush block polymer consists of one main polymer chain and countless side polymer chains, and the main chain is very stretched owing to the great spatial repulsion effect between the side chains. Different from linear polymers, the polymer has special configuration, greatly reduces molecular chain entanglement, and remarkably accelerates self-assembly kinetics. Even when the molecular weight reaches millions of Da, a sample can still form a good microstructure in a few minutes through self-assembly, the structural size is expanded from dozens of nanometers to hundreds of nanometers, interaction with visible light can be further realized, and the method can be applied to a plurality of fields such as photonic crystal display, optical sensors, anti-counterfeiting marks, food detection, photonic chips and the like.

While the preparation of polymer brushes in the prior art is usually carried out in a round-bottom flask or a batch reactor, the traditional synthesis method has the problems of complicated operation, time consumption, low yield, high cost and the like, and the product with narrower molecular weight distribution is difficult to obtain due to the lower mass and heat transfer efficiency. With the continuous progress of reaction engineering technology, chemical synthesis is developing towards more high efficiency, safety and automation, and continuous flow synthesis technology has been successfully applied to different types of polymerization reactions, but the currently reported continuous flow synthesis is only limited to the polymerization of small organic molecular monomers, the molecular weight of the product is low, and is limited by the viscosity of the reaction solution, and no method is available for preparing a high molecular weight product with narrow molecular weight distribution.

Disclosure of Invention

The invention aims to provide a method for synthesizing a block copolymer brush by utilizing microfluidics, which aims to solve the problems in the prior art, so that a high molecular weight block copolymer brush with narrow molecular weight distribution is prepared on the basis of automatically and accurately controlling molecular weight and molecular weight distribution.

In order to achieve the purpose, the invention provides the following scheme:

the invention provides a method for synthesizing a block copolymer brush by utilizing microfluidics, which comprises the following steps:

preparing a polymerization monomer and a catalyst of the block copolymer brush into a solution, and placing the solution in a liquid storage tank of a syringe pump;

connecting a corresponding number of microreactors in series according to the number of blocks of the block copolymer brush, connecting an injection pump with a catalyst solution with an inlet of a first microreactor, and connecting the injection pump with a corresponding polymerization monomer solution with inlets of the microreactors in a corresponding sequence according to a block sequence;

setting flow speed and flow speed ratio according to the polymerization degree and the block proportion of the block copolymer brush;

and collecting the solution of the block copolymer brush at the outlet of the last microreactor, and removing the solvent to obtain the block copolymer brush.

The solvent used for preparing the solution is an organic solvent, and comprises dichloromethane, tetrahydrofuran, toluene, trichloromethane and N, N-dimethylformamide.

Further, the microreactor has at least two inlets and one outlet.

Furthermore, the microreactors are connected in series in such a way that an outlet of an upper microreactor is connected with an inlet of a lower microreactor, and the other inlet of the lower microreactor is a feed inlet of a monomer.

Further, the microreactor includes a circular tube type and a microchip type reactor.

Furthermore, the inner diameter of the channel of the microreactor is 10-1000 μm.

The pore channel of the micro-reactor comprises a straight tube type, a zigzag type, an S type and an hourglass type, and the cross section of the micro-reactor comprises a round shape, a square shape, a trapezoid shape, a semicircular shape and a triangular shape.

Further, the injection speed of the injection pump is 0.005-50 mL/min.

Further, the topology of the block copolymer brush is a bottle brush type.

Further, the polymerized monomer is a cyclic olefin polymerized monomer, specifically a macromonomer having a cyclic olefin polymerized unit at the terminal and having a molecular weight of 500-.

More specifically, the cycloolefin polymer monomer includes macromonomers such as Polystyrene (PS) having a norbornene group at a terminal, polyethylene glycol (PEO), Polydimethylsiloxane (PDMS), Polycaprolactone (PCL), Polylactide (PLA), poly (t-butyl acrylate) (PtBA), poly (methyl methacrylate) (PMMA), and the like.

The molecular weight and the degree of polymerization of the block copolymer brush are as follows: the polymerization degree of the polymer main chain is between 10 and 2000, the polymerization degree of the blocks is between 5 and 500, the number of the blocks is 1 to 4, the molecular weight range of the side chain is 500-20000Da, and the molecular weight range of the block copolymer brush is 5000-20000000 Da.

Further, the concentration of the polymerization monomer solution is 1-1500 mmol/L.

The invention discloses the following technical effects:

(1) the programmed automatic synthesis method provided by the invention shows incomparable advantages of traditional manual feeding in the aspects of repeatability, safety, accuracy and the like, overcomes the defects that a traditional synthesis mode is difficult to obtain a product with narrow molecular weight distribution, the existing continuous flow reaction mode is limited to polymerization of small organic molecular monomers, and the molecular weight of the product is low, establishes a universal method for preparing a large molecular weight block copolymer brush with a complex structure in batches, has the advantages of rapidness, high accuracy, simplicity and convenience in operation, continuous production and the like, and can obviously improve the production efficiency and reduce the cost.

(2) The block copolymer brush synthesized by the invention has the advantages of precisely controlled molecular weight and molecular weight distribution, narrow molecular weight distribution and large molecular weight of the block copolymer brush, and the block copolymer brushes are expected to play important roles in the fields of macromolecules, biology and the like.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic diagram of the process of the present invention for continuous flow reaction to synthesize block copolymer brushes;

FIG. 2 is a schematic channel view of a continuous flow reactor of the present invention.

Detailed Description

Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention.

It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference herein for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.

It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification. The description and examples are intended to be illustrative only.

As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.

The microreactors used in the embodiment of the invention all comprise two inlets, namely an inlet I and an inlet II.

Example 1

A method for synthesizing block copolymer brush PLA-b-PEO using microfluidics, comprising the steps of:

(1) NB-PLA (norbornene-terminated polylactic acid) macromonomer (molecular weight is 4190Da, molecular weight distribution index is 1.1), NB-PEO (norbornene-terminated polyethylene glycol) macromonomer (molecular weight is 1120Da, molecular weight distribution index is 1.09) and Grubbs third-generation catalyst (relative molecular weight is 884.53Da) are respectively prepared into 110mmol/L, 55mmol/L and 2.2mmol/L ultra-dry dichloromethane solutions, and the solutions are respectively placed in liquid storage tanks of three injection pumps.

(2) Respectively connecting an injection pump with a catalyst solution, an NB-PLA solution and an NB-PEO solution with an inlet I of a first microreactor, an inlet II of the first microreactor and an inlet II of a second microreactor, wherein an outlet of the first microreactor is connected with an inlet I of the second microreactor, and the flow rates are respectively set to be 0.1ml/min, 0.1ml/min and 0.2 ml/min;

wherein the inner diameter of the channel of the micro-reactor is 250 μm, and belongs to a microchip type reactor.

(3) The run was started and the polymer solution was collected at the outlet of the second microreactor.

(4) Drying the collected polymer solution, and removing solvent to obtain PLA-b-PEO polymer brush with polymerization degree of PLA block of 50, polymerization degree of PEO block of 50, and molecular weight of 3.1 × 10⁵Da, molecular weight distribution index of 1.19.

Example 2

A method for synthesizing block copolymer brush PS-b-PEO using microfluidics, comprising the steps of:

(1) respectively preparing 110mmol/L, 55mmol/L and 2.2mmol/L ultra-dry dichloromethane solutions from NB-PS (norbornene-terminated polystyrene) macromonomer, NB-PEO (norbornene-terminated polyethylene glycol) macromonomer and Grubbs third-generation catalyst, and placing the solutions in liquid storage tanks of three injection pumps.

Wherein, the molecular weight of the NB-PS is 4520Da, and the molecular weight distribution index is 1.07; the molecular weight of NB-PEO was 412Da, the molecular weight distribution index was 1.1, and the relative molecular mass of the catalyst was 884.53 Da.

(2) And respectively connecting an injection pump with a catalyst solution, an NB-PS solution and an NB-PEO solution with an inlet I of a first microreactor, an inlet II of the first microreactor and an inlet II of a second microreactor, wherein an outlet of the first microreactor is connected with an inlet I of the second microreactor, and the flow rates are respectively set to be 0.15ml/min, 0.15ml/min and 0.3 ml/min. Wherein, the inner diameter of the channel of the micro-reactor is 250 μm, and belongs to a microchip type reactor.

(3) The run was started and the polymer solution was collected at the outlet of the second microreactor.

(4) Drying the collected polymer solution to remove solvent to obtain PS-b-PEO polymer brush, wherein the polymerization degree of the PS block is 50, the polymerization degree of the PEO block is 50, and the molecular weight is 4.1 × 10⁵Da, molecular weight distribution index of 1.18.

Example 3

A method for synthesizing block copolymer brush PS-b-PDMS by using microfluidics, comprising the steps of:

(1) respectively preparing 110mmol/L, 55mmol/L and 2.2mmol/L ultra-dry dichloromethane solutions from NB-PS (norbornene-terminated polystyrene) macromonomer, NB-PDMS (norbornene-terminated polydimethylsiloxane) macromonomer and Grubbs third-generation catalyst, and placing the solutions in liquid storage tanks of three injection pumps. Wherein, the molecular weight of NB-PS is 4520Da, the molecular weight distribution index is 1.07, the molecular weight of NB-PDMS is 4790Da, the molecular weight distribution index is 1.11, and the relative molecular weight of the catalyst is 884.53 Da.

(2) And respectively connecting an injection pump with a catalyst solution, an NB-PS solution and an NB-PDMS solution with an inlet I of a first microreactor, an inlet II of the first microreactor and an inlet II of a second microreactor, wherein an outlet of the first microreactor is connected with an inlet I of the second microreactor, and the flow rates are set to be 0.15ml/min, 0.15ml/min and 0.3 ml/min. Wherein the inner diameter of the channel of the micro-reactor is 250 μm, and belongs to a microchip type reactor.

(3) The run was started and the polymer solution was collected at the outlet of the second microreactor.

(4) Drying the collected polymer solution to remove the solvent, and obtaining the PS-b-PDMS polymer brush, wherein the polymerization degree of the PS block is 50, the polymerization degree of the PDMS block is 50, and the molecular weight is 4.3 multiplied by 10⁵Da, molecular weight distribution index of 1.13.

Example 4

A method for synthesizing a block copolymer brush PEO-b-PDMS by using microfluidics, comprising the following steps:

(1) NB-PEO (norbornene-terminated polyethylene glycol) macromonomer, NB-PDMS (norbornene-terminated polydimethylsiloxane) macromonomer and Grubbs third-generation catalyst are respectively prepared into 110mmol/L, 55mmol/L and 2.2mmol/L ultra-dry dichloromethane solutions, and the solutions are placed in liquid storage tanks of three injection pumps. Wherein the molecular weight of NB-PEO is 4120Da, the molecular weight distribution index is 1.1, the molecular weight of NB-PDMS is 4790Da, the molecular weight distribution index is 1.11, and the relative molecular mass of the catalyst is 884.53 Da.

(2) And respectively connecting an injection pump with a catalyst solution, an NB-PEO solution and an NB-PDMS solution with an inlet I of a first microreactor, an inlet II of the first microreactor and an inlet II of a second microreactor, wherein an outlet of the first microreactor is connected with an inlet I of the second microreactor, and the flow rates are set to be 0.15ml/min, 0.15ml/min and 0.3 ml/min. The inner diameter of the channel of the microreactor is 250 μm, and the microreactor belongs to a microchip type reactor.

(3) The run was started and the polymer solution was collected at the outlet of the second microreactor.

(4) Drying the collected polymer solution to remove the solvent, and obtaining the PEO-b-PDMS polymer brush, wherein the polymerization degree of the PEO block is 50, the polymerization degree of the PDMS block is 50, and the molecular weight is 4.6 multiplied by 10⁵Da, molecular weight distribution index of 1.15.

Example 5

A method for synthesizing a block copolymer brush PS-b-PtBA-b-PEO by microfluidics, comprising the steps of:

(1) respectively preparing 110mmol/L, 55mmol/L, 22.5mmol/L and 2.2mmol/L ultra-dry dichloromethane solutions from NB-PS (norbornene-terminated polystyrene) macromonomer, NB-PtBA (norbornene-terminated poly (tert-butyl acrylate)) macromonomer, NB-PEO (norbornene-terminated polyethylene glycol) macromonomer and Grubbs third-generation catalyst, and placing the solutions in liquid storage tanks of three injection pumps. Wherein the molecular weight of NB-PS is 4520Da, the molecular weight distribution index is 1.07, the molecular weight of NB-PtBA is 4320Da, the molecular weight distribution index is 1.11, the molecular weight of NB-PEO is 4120Da, the molecular weight distribution index is 1.1, and the relative molecular weight of the catalyst is 884.53 Da.

(2) And respectively connecting an injection pump with a catalyst solution, an NB-PS solution, an NB-PtBA solution and an NB-PEO solution with an inlet I of a first microreactor, an inlet II of the first microreactor, an inlet II of a second microreactor and an inlet II of a third microreactor, wherein an outlet of the first microreactor is connected to an inlet I of the second microreactor, an outlet of the second microreactor is connected to an inlet I of the third microreactor, and the flow rates are set to be 0.15ml/min, 0.3ml/min and 0.6 ml/min. The inner diameter of the channel of the microreactor is 250 μm, and the microreactor belongs to a microchip type reactor.

(3) The run was started and the polymer solution was collected at the outlet of the third microreactor.

(4) Drying the collected polymer solution to remove the solvent, and obtaining the PS-b-PtBA-b-PEO polymer brush, wherein the polymerization degree of the PS block is 50, the polymerization degree of the PtBA block is 50, the polymerization degree of the PEO block is 50, and the molecular weight is 6.1 multiplied by 10⁵Da, molecular weight distribution index of 1.22.

Example 6

A method for synthesizing block copolymer brush PLA-b-PEO using microfluidics, comprising the steps of:

(1) respectively preparing 110mmol/L, 55mmol/L and 0.22mmol/L ultra-dry dichloromethane solutions from NB-PLA (norbornene-terminated polylactic acid) macromonomer, NB-PEO (norbornene-terminated polyethylene glycol) macromonomer and Grubbs third-generation catalyst, and placing the solutions in liquid storage tanks of three injection pumps. Wherein the molecular weight of NB-PLA is 1190Da, the molecular weight distribution index is 1.07, the molecular weight of NB-PEO is 1120Da, the molecular weight distribution index is 1.09, and the relative molecular mass of the catalyst is 884.53 Da.

(2) And respectively connecting an injection pump with a catalyst solution, an NB-PLA solution and an NB-PEO solution with an inlet I of a first microreactor, an inlet II of the first microreactor and an inlet II of a second microreactor, wherein an outlet of the first microreactor is connected with an inlet I of the second microreactor, and the flow rates are set to be 0.1ml/min, 0.1ml/min and 0.2 ml/min. The inner diameter of the channel of the microreactor is 50 μm and belongs to a microchip reactor.

(3) The run was started and the polymer solution was collected at the outlet of the second microreactor.

(4) Drying the collected polymer solution to remove the solvent, and obtaining the PLA-b-PEO polymer brush, wherein the polymerization degree of the PLA block is 500, the polymerization degree of the PEO block is 500, and the molecular weight is 1 multiplied by 10⁶Da, molecular weight distribution index 1.26.

Example 7

A method for synthesizing block copolymer brush PLA-b-PEO using microfluidics, comprising the steps of:

(1) respectively preparing 11mmol/L, 5.5mmol/L and 2.2mmol/L ultra-dry dichloromethane solutions from NB-PLA (norbornene-terminated polylactic acid) macromonomer, NB-PEO (norbornene-terminated polyethylene glycol) macromonomer and Grubbs third-generation catalyst, and placing the solutions in liquid storage tanks of three injection pumps. Wherein the molecular weight of NB-PLA is 1190Da, the molecular weight distribution index is 1.07, the molecular weight of NB-PEO is 1120Da, the molecular weight distribution index is 1.09, and the relative molecular mass of the catalyst is 884.53 Da.

(2) And respectively connecting an injection pump with a catalyst solution, an NB-PLA solution and an NB-PEO solution with an inlet I of a first microreactor, an inlet II of the first microreactor and an inlet II of a second microreactor, wherein an outlet of the first microreactor is connected with an inlet I of the second microreactor, and the flow rates are set to be 0.1ml/min, 0.1ml/min and 0.2 ml/min. The inner diameter of the channel of the microreactor is 50 μm and belongs to a microchip reactor.

(3) The run was started and the polymer solution was collected at the outlet of the second microreactor.

(4) Drying the collected polymer solution to remove the solvent, and obtaining the PLA-b-PEO polymer brush, wherein the polymerization degree of the PLA block is 5, the polymerization degree of the PEO block is 5, and the molecular weight is 1.2 multiplied by 10⁴Da, molecular weight distribution index of 1.08.

Example 8

A method for synthesizing block copolymer brush PLA-b-PEO using microfluidics, comprising the steps of:

(1) respectively preparing an ultra-dry dichloromethane solution of 550mmol/L, 550mmol/L and 11mmol/L from an NB-PLA (norbornene-terminated polylactic acid) macromonomer, an NB-PEO (norbornene-terminated polyethylene glycol) macromonomer and a Grubbs third-generation catalyst, and placing the solution in liquid storage tanks of three injection pumps. Wherein the molecular weight of NB-PLA is 1190Da, the molecular weight distribution index is 1.07, the molecular weight of NB-PEO is 1120Da, the molecular weight distribution index is 1.09, and the relative molecular mass of the catalyst is 884.53 Da.

(2) And respectively connecting an injection pump with a catalyst solution, an NB-PLA solution and an NB-PEO solution with an inlet I of a first microreactor, an inlet II of the first microreactor and an inlet II of a second microreactor, wherein an outlet of the first microreactor is connected with an inlet I of the second microreactor, and the flow rates are set to be 0.2ml/min, 0.2ml/min and 0.4 ml/min. The inner diameter of the channel of the microreactor is 250 μm, and the microreactor belongs to a microchip type reactor.

(3) The run was started and the polymer solution was collected at the outlet of the second microreactor.

(4) Drying the collected polymer solution to remove the solvent, and obtaining the PLA-b-PEO polymer brush, wherein the polymerization degree of the PLA block is 50, the polymerization degree of the PEO block is 100, and the molecular weight is 1.5 multiplied by 10⁵Da, molecular weight distribution index of 1.12.

Example 9

A method for synthesizing block copolymer brush PLA-b-PEO using microfluidics, comprising the steps of:

(1) respectively preparing an ultra-dry dichloromethane solution of 1100mmol/L, 550mmol/L and 220mmol/L from an NB-PLA (norbornene-terminated polylactic acid) macromonomer, an NB-PEO (norbornene-terminated polyethylene glycol) macromonomer and a Grubbs third-generation catalyst, and placing the ultra-dry dichloromethane solution in liquid storage tanks of three injection pumps. Wherein the molecular weight of NB-PLA is 670Da, the molecular weight distribution index is 1.08, the molecular weight of NB-PEO is 670Da, the molecular weight distribution index is 1.1, and the relative molecular mass of the catalyst is 884.53 Da.

(2) And respectively connecting an injection pump with a catalyst solution, an NB-PLA solution and an NB-PEO solution with an inlet I of a first microreactor, an inlet II of the first microreactor and an inlet II of a second microreactor, wherein an outlet of the first microreactor is connected with an inlet I of the second microreactor, and the flow rates are set to be 0.2ml/min, 0.2ml/min and 0.4 ml/min. The inner diameter of the channel of the microreactor is 500 μm and belongs to a microchip reactor.

(3) The run was started and the polymer solution was collected at the outlet of the second microreactor.

(4) Drying the collected polymer solution to remove the solvent, and obtaining the PLA-b-PEO polymer brush, wherein the polymerization degree of the PLA block is 50, the polymerization degree of the PEO block is 50, and the molecular weight is 7 multiplied by 10⁴Da, molecular weight distribution index of 1.13.

Example 10

A method for synthesizing block copolymer brush PS-b-PEO using microfluidics, comprising the steps of:

(1) NB-PS (norbornene-terminated polystyrene) macromonomer, NB-PEO (norbornene-terminated polyethylene glycol) macromonomer and Grubbs third-generation catalyst are respectively prepared into 55mmol/L, 22.5mmol/L and 0.11mmol/L ultra-dry dichloromethane solutions which are placed in liquid storage tanks of three injection pumps. Wherein the molecular weight of NB-PS is 15000Da, the molecular weight distribution index is 1.13, the molecular weight of NB-PEO is 14220Da, the molecular weight distribution index is 1.15, and the relative molecular mass of the catalyst is 884.53 Da.

(2) And respectively connecting an injection pump with a catalyst solution, an NB-PS solution and an NB-PEO solution with an inlet I of a first microreactor, an inlet II of the first microreactor and an inlet II of a second microreactor, wherein an outlet of the first microreactor is connected with an inlet I of the second microreactor, and the flow rates are set to be 2ml/min, 2ml/min and 4 ml/min. The inner diameter of the channel of the microreactor is 800 μm, and the microreactor belongs to a microchip type reactor.

(3) The run was started and the polymer solution was collected at the outlet of the second microreactor.

(4) Drying the collected polymer solution to remove the solvent, and obtaining the PS-b-PEO polymer brush, wherein the polymerization degree of the PS block is 250, the polymerization degree of the PEO block is 250, and the molecular weight is 7.5 multiplied by 10⁶Da, molecular weight distribution index of 1.24.

Example 11

A method for synthesizing a block copolymer brush PS-b-PtBA-b-PEO-PDMS by utilizing microfluidics comprises the following steps:

(1) respectively preparing 110mmol/L, 55mmol/L, 22.5mmol/L, 11.25mmol/L and 2.2mmol/L ultra-dry dichloromethane solutions from NB-PS (norbornene-terminated polystyrene) macromonomer, NB-PtBA (norbornene-terminated poly (tert-butyl acrylate)) macromonomer, NB-PEO (norbornene-terminated polyethylene glycol) macromonomer, NB-PDMS (norbornene-terminated polydimethylsiloxane) macromonomer and Grubbs third-generation catalyst, and placing the solutions in liquid storage tanks of three injection pumps. Wherein, the molecular weight of NB-PS is 4520Da, the molecular weight distribution index is 1.07, the molecular weight of NB-PtBA is 4320Da, the molecular weight distribution index is 1.11, the molecular weight of NB-PEO is 4120Da, the molecular weight distribution index is 1.1, the molecular weight of NB-PDMS is 4790Da, the molecular weight distribution index is 1.08, and the relative molecular weight of the catalyst is 884.53 Da.

(2) Respectively connecting an injection pump with a catalyst solution, an NB-PS solution, an NB-PtBA, an NB-PEO and an NB-PDMS solution with an inlet I of a first microreactor, an inlet II of the first microreactor, an inlet II of a second microreactor, an inlet II of a third microreactor and an inlet II of a fourth microreactor, wherein an outlet of the first microreactor is connected with an inlet I of the second microreactor, an outlet of the second microreactor is connected with an inlet I of the third microreactor, an outlet of the third microreactor is connected with an inlet I of the fourth microreactor, and the flow rates are set to be 0.15ml/min, 0.3ml/min, 0.6ml/min and 1.2 ml/min. The inner diameter of the channel of the microreactor is 250 μm, and the microreactor belongs to a microchip type reactor.

(3) The run was started and the polymer solution was collected at the outlet of the fourth microreactor.

(4) Drying the collected polymer solution to remove the solvent, and obtaining the PS-b-PtBA-b-PEO-PDMS polymer brush, wherein the polymerization degree of the PS block is 50, the polymerization degree of the PtBA block is 50, the polymerization degree of the PEO block is 50, the polymerization degree of the PDMS block is 50, and the molecular weight is 8.1 multiplied by 10⁵Da, molecular weight distribution index of 1.23.

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.