A polymer brush containing single-stranded polymer nanoparticles and a preparation method thereof

Abstract

The application provides a single-chain polymer nanoparticle-containing polymer brush and a preparation method thereof, and belongs to the field of high polymer materials. The single-chain polymer nanoparticle-containing polymer brush is obtained by substituting a linear polymer chain with single-chain polymer nanoparticles with specific size and structure in a high molecular weight linear main chain. The prepared special topological structure polymer brush exhibits unique rheological behavior in a solution. The unique rheological behavior is mainly embodied in the reduction of chain entanglement between molecular chains, the reduction of viscosity of the system, the acceleration of chain relaxation rate, and the increase of mesh size between entangled chains.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of high polymer materials, and particularly relates to a single-chain polymer nanoparticle-containing polymer brush and a preparation method thereof. BACKGROUND

[0002] Since Hermann Staudinger proposed the "macromolecular hypothesis" in 1920, polymers have fundamentally changed modern society. In the past century, polymers have been made into disposable containers, cost-effective electronic products, rigid but lightweight components for vehicles and aircraft, and innovative biomaterials. However, in recent decades, the demand for materials with special properties has expanded, particularly in special field applications such as military and medical. Therefore, chemists have increasingly focused on designing polymer structures that can meet the required performance standards. With the advent of advanced synthesis techniques, especially "living" controlled polymerization and post-polymerization modification, a large number of polymers with complex topologies have been reported to be synthesized, such as branched, cyclic, and star-shaped polymers. These complex topological polymers exhibit unexpected solution and melt properties that have attracted the interest of researchers.

[0003] Polymer "brushes" are polymers that have attracted widespread interest in the past decade, which are composed of polymer chains attached to a substrate through physical interactions or terminal covalent bonds. The high density of chains on the substrate leads to the brush-like conformation of this type of polymer, with polymer chains extending vertically from the substrate. This unique structure enables polymer "brushes" to significantly alter the physicochemical properties of surfaces, making them one of the most valuable tools for controlling surface / interface properties. In the past few decades, polymer brushes have been widely used in cutting-edge fields such as antifouling and anti-icing agents, surface lubrication, and biological surface response.

[0004] The performance of polymer "brushes" is significantly influenced by various factors, including the composition of their main chain and grafted chains (such as hydrophilic and hydrophobic units), grafting density, and length of grafted molecular chains. However, there has been limited attention on the influence of the topology and size of side chains attached to polymer brushes on material performance. The use of polymers with unique topologies in the development of functional materials has proven to be a very successful strategy. Examples include the use of cyclic polymers to construct polymer networks, polyhedral oligomeric silsesquioxanes (POSS) as reactive components in the synthesis of pearl-chain polymers, and the use of molecular networks to create topological gels. In our previous research, we successfully manufactured a reversible topological network using functional single-chain nanoparticles (SCNPs) as cross-linking agents. The introduction of SCNPs with unique structures and specific sizes as side groups grafted into high molecular weight linear polymer main chains opens up exciting possibilities for changing the material properties of polymer brushes. The potential revolutionary impact of this integration on the performance of polymer brushes needs further exploration and research. SUMMARY

[0005] The present application is based on the above background art, and aims to provide a polymer brush containing single-chain polymer nanoparticles and a preparation method thereof.

[0006] The present application provides a preparation method of a polymer brush containing single-chain polymer nanoparticles, having the following features, comprising the following steps: S10, using any 2-4 of methyl methacrylate, 2-(acetoacetoxy) ethyl methacrylate, furfuryl methacrylate, maleimide functionalized methacrylate or anthryl methacrylate as monomers to synthesize a linear polymer containing active end groups; S20, carrying out intramolecular crosslinking reaction on the linear polymer containing active end groups to obtain single-chain intramolecularly crosslinked polymer nanoparticles containing active end groups; S30, using methyl methacrylate and hydrazide methacrylate as monomers to prepare a high molecular weight linear polymer containing active side groups by free radical polymerization; S40, grafting the single-chain intramolecularly crosslinked polymer nanoparticles containing active end groups to the high molecular weight linear polymer containing active side groups by grafting reaction to obtain the polymer brush containing single-chain polymer nanoparticles.

[0007] In the preparation method of the polymer brush containing single-chain polymer nanoparticles provided by the present application, the step S10 can further comprise the following sub-steps: S11, putting any 2-4 of methyl methacrylate, 2-(acetoacetoxy) ethyl methacrylate, furfuryl methacrylate, maleimide functionalized methacrylate or anthryl methacrylate, an initiator and a ligand into a polymerization reaction bottle, and then vacuumizing for a predetermined time; S12, putting a catalyst, continuing vacuumizing to remove oxygen, and then heating to react to obtain a first pre-product; S13, dissolving the first pre-product in ethyl acetate, and then dropping into ethanol to settle to obtain the first polymer after settling; S14, drying the first polymer to constant weight to obtain the linear polymer containing active end groups.

[0008] In the preparation method of the polymer brush containing single-chain polymer nanoparticles provided by the present application, in the step S11, the initiator is an ATRP initiator, and in the step S12, the catalyst is CuBr and the ligand is PMDETA.

[0009] In the preparation method of the polymer brush containing single-chain polymer nanoparticles provided by the present application, the step S20 can further comprise the following sub-steps: S21, dissolving the linear polymer containing active end groups in an excess of solvent to obtain an extremely dilute solution; S22, reacting the raw materials in the extremely dilute solution, removing the solvent after the reaction is completed to obtain a primary product; S23, putting the primary product into methanol to obtain the single-chain intramolecularly crosslinked polymer nanoparticles containing active end groups.

[0010] In the preparation method of the polymer brush containing single-chain polymer nanoparticles provided in the application, the following features can also be present: in step S21, the solvent in the extremely dilute solution comprises THF or DMF, and the concentration of the linear polymer containing active end groups in the extremely dilute solution is not higher than 1 g / L; in step S22, the reaction method is ultraviolet irradiation reaction in an ultraviolet reactor or direct heating reaction for 24 h; when the ultraviolet irradiation reaction is used, the wavelength of light is 360 nm; and when the direct heating reaction is used, the heating method is slow heating to 120 °C and then slow cooling to room temperature.

[0011] In the preparation method of the polymer brush containing single-chain polymer nanoparticles provided in the application, the following features can also be present: step S30 comprises the following sub-steps: S31, methyl methacrylate, methyl methacrylate hydrazide and an initiator are put into a polymerization reaction bottle, vacuum is drawn and maintained for a predetermined time, and then heating reaction is performed to obtain a second pre-product; S32, after the second pre-product is dissolved in ethyl acetate, it is dropped into ethanol for sedimentation to obtain a second polymer after sedimentation; and S33, the second polymer is dried to constant weight to obtain a high molecular weight linear polymer containing active side groups.

[0012] In the preparation method of the polymer brush containing single-chain polymer nanoparticles provided in the application, the following features can also be present: in step S31, the molar ratio of methyl methacrylate to methyl methacrylate hydrazide is 7:3, and the initiator comprises azobisisobutyronitrile.

[0013] In the preparation method of the polymer brush containing single-chain polymer nanoparticles provided in the application, the following features can also be present: step S40 comprises the following steps: S41, the single-chain intracrosslinking polymer nanoparticles containing active end groups and the high molecular weight linear polymer containing active side groups are put into a solvent for reaction; S42, after the reaction is completed, the reaction solution is dropped into ethanol for sedimentation to obtain a third polymer; and S43, the third polymer is dried to constant weight to obtain the polymer brush containing single-chain polymer nanoparticles.

[0014] In the preparation method of the polymer brush containing single-chain polymer nanoparticles provided in the application, the following features can also be present: in step S41, the mass ratio of the single-chain intracrosslinking polymer nanoparticles containing active end groups to the high molecular weight linear polymer containing active side groups is 3:7, and the solvent comprises DMF.

[0015] The present application also provides a single-chain polymer nanoparticle-containing polymer brush, which is prepared by the preparation method of the single-chain polymer nanoparticle-containing polymer brush according to any one of the preceding embodiments, and has the characteristics of less chain entanglement between molecular chains, lower viscosity of the system, faster chain relaxation rate, larger mesh size between entangled chains, and wide application range of the single-chain polymer nanoparticle-containing polymer brush, including viscosity regulator or surfactant.

[0016] Effects of the application

[0017] According to the single-chain polymer nanoparticle-containing polymer brush and the preparation method thereof provided by the present application, the linear polymer is replaced by the single-chain polymer nanoparticle with specific size and structure to be grafted in the linear main chain with high molecular weight, so that the special topological structure polymer brush prepared by the present application has unique rheological behavior in solution. The unique rheological behavior mainly includes less chain entanglement between molecular chains, lower viscosity of the system, faster chain relaxation rate, and larger mesh size between entangled chains. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a flow chart of the preparation method of the single-chain polymer nanoparticle-containing polymer brush according to an embodiment of the present application;

[0019] Figure 2 is a synthesis route diagram of sample 1 or 2 according to an embodiment of the present application;

[0020] Figure 3 is a nuclear magnetic resonance diagram of F-LP and T-SCNP in the preparation of sample 1 according to an embodiment of the present application;

[0021] Figure 4 is a particle size distribution diagram of F-LP and T-SCNP in the preparation of sample 1 according to an embodiment of the present application;

[0022] Figure 5 is a SEC outflow curve diagram of F-LP and T-SCNP in the preparation of sample 1 according to an embodiment of the present application;

[0023] Figure 6 is a nuclear magnetic resonance diagram of the single-chain polymer nanoparticle-containing polymer brush (combo of T-SCNP) before and after reaction in the preparation of sample 1 according to an embodiment of the present application;

[0024] Figure 7 is a particle size distribution diagram of the single-chain polymer nanoparticle-containing polymer brush (combo of T-SCNP) before and after reaction in the preparation of sample 1 according to an embodiment of the present application;

[0025] Figure 8 is a SEC elution profile of the single-chain polymer nanoparticle-containing polymer brush (combo of T-SCNP) before and after the preparation of sample 1 in the embodiment of the present application;

[0026] Figure 9 is a self-correlation function profile of the single-chain polymer nanoparticle-containing polymer brush (combo of T-SCNP) prepared in the embodiment of the present application;

[0027] Figure 10 is a modulus over time profile of the single-chain polymer nanoparticle-containing polymer brush (combo of T-SCNP) prepared in the embodiment of the present application;

[0028] Figure 11 is a viscosity over time profile of the single-chain polymer nanoparticle-containing polymer brush (combo of T-SCNP) prepared in the embodiment of the present application in solution;

[0029] Figure 12 is a relaxation time profile of the single-chain polymer nanoparticle-containing polymer brush (combo of T-SCNP) prepared in the embodiment of the present application in solution. DETAILED DESCRIPTION

[0030] In order to make the technical means, creative features, purposes and effects of the present application easy to understand, the following embodiments will be specifically described in combination with the drawings.

[0031] <EMBODIMENT>

[0032] Figure 1 is a flowchart of a preparation method of a single-chain polymer nanoparticle-containing polymer brush in the embodiment of the present application; Figure 2 is a synthesis route diagram of sample 1 or 2 in the embodiment of the present application.

[0033] As shown in Figure 1 and 2 , the present embodiment provides a preparation method of a single-chain polymer nanoparticle-containing polymer brush, comprising the following steps:

[0034] S10, synthesizing a linear polymer (F-LP) containing a living end group, specifically comprising the following sub-steps:

[0035] S11, any 2-4 of methyl methacrylate (MMA), 2-(acetoacetoxy) ethyl methacrylate (AEMA), furfuryl methacrylate (FMA), maleimide functionalized methacrylate (MIMA) or anthryl methacrylate (AMA), ATRP initiator and ligand PMDETA are put into a polymerization reaction bottle, and then vacuum is drawn for 40 min;

[0036] S12, a catalyst CuBr is put in, and after oxygen is removed for 15 min, the reaction is carried out in an oil bath at 60°C for 12 h to obtain a first pre-product;

[0037] S13, after the first pre-product is dissolved in ethyl acetate, it is dropped into ethanol to settle, and a settled first polymer is obtained;

[0038] S14, the first polymer is placed in a normal temperature vacuum drying box and dried for 24 h to constant weight to obtain F-LP.

[0039] S20, the F-LP is subjected to intramolecular crosslinking reaction to obtain a single-chain intracrosslinked polymer nanoparticle (T-SCNP) containing active end groups, specifically comprising the following sub-steps:

[0040] S21, the F-LP is dissolved in excess solvent A to obtain an extremely dilute solution;

[0041] S22, the raw materials in the extremely dilute solution are reacted for 24 h, and after the reaction is completed, the solvent A is removed to obtain a primary product;

[0042] S23, the primary product is put into methanol to obtain T-SCNP.

[0043] S30, a high molecular weight linear polymer (H-LP) containing active side groups is prepared by free radical polymerization, specifically comprising the following sub-steps:

[0044] S31, methyl methacrylate (MMA), methacrylic hydrazide ester (MAH) and initiator azobisisobutyronitrile (AIBN) are put into a 100 mL polymerization reaction bottle with a magnetic stirrer according to a molar ratio of 70:30:0.1 (the actual amounts of raw materials are 1.4 g, 0.6 g and 2.3 mg, respectively), vacuum is maintained for a predetermined time, and then the reaction is heated to obtain a second pre-product;

[0045] S32, after the second pre-product is dissolved in 5 mL of ethyl acetate, it is dropped into ethanol to settle, and a settled second polymer is obtained;

[0046] S33, the second polymer is placed in a normal temperature vacuum drying box and dried to constant weight to obtain H-LP.

[0047] S40, grafting T-SCNPs onto H-LPs through an acylhydrazone chemical reaction to prepare a polymer brush containing single-chain polymer nanoparticles (comb of T-SCNPs), specifically comprising the following sub-steps:

[0048] S41, 0.3 g of T-SCNP and 0.1 g of H-LP were added to DMF solvent and stirred at room temperature for 24 h;

[0049] S42, after the reaction is completed, the reaction solution is dropped into ethanol for precipitation to obtain a third polymer;

[0050] S43, placing the third polymer in a vacuum drying oven at room temperature and drying it to a constant weight to obtain a polymer brush containing single-chain polymer nanoparticles (comb of T-SCNP).

[0051] This embodiment also provides a polymer brush containing single-chain polymer nanoparticles, which is prepared by the above-mentioned method for preparing a polymer brush containing single-chain polymer nanoparticles.

[0052] In this example, three different polymer brushes containing single-chain polymer nanoparticles (comb of T-SCNP) were prepared, which were respectively labeled as sample 1, sample 2, and sample 3. The specific feed amounts and reaction types are shown in Table 1.

[0053] Table 1 (Comparison of specific feed amounts and reaction types of samples 1 to 3)

[0054]

[0055] <Test Example>

[0056] This test example performs relevant tests on the polymer brush containing single-chain polymer nanoparticles prepared in Example.

[0057] Figure 3 1 is the NMR image of F-LP and T-SCNP during the preparation of sample 1 in an embodiment of the present invention.

[0058] like Figure 3 As shown, according to 1 H NMR calculations determined the F-LP composition by observing the ratio of methylene protons of the methyl methacrylate segments at 3.51 ppm to the total aromatic protons of the anthracene units at 7.51 to 8.52 ppm, indicating that the copolymer (F-LP) contained 30 mol% anthracene units. Upon dimerization of anthracene, the proton peaks at 7.51-8.52 ppm shifted downfield, indicating internal cross-linking.

[0059] Figure 4is a graph of the particle size distribution of F-LP and T-SCNP during the preparation of Sample 1 in the embodiments of the present application.

[0060] As shown in Figure 4 , the size of T-SCNP during the preparation of Sample 1 can be measured by DLS to be 5 nm, and the particle size is reduced due to the more compact structure of T-SCNP relative to F-LP.

[0061] Figure 5 is a graph of the SEC elution profile of F-LP and T-SCNP during the preparation of Sample 1 in Embodiment 1 of the present application.

[0062] As shown in Figure 5 , after the intramolecular crosslinking of F-LP to form T-SCNP, the elution volume is reduced, and the elution time in the gel chromatography column is longer, indicating that the apparent molecular weight is reduced.

[0063] Figure 6 is a graph of the NMR spectra of the single-stranded polymer nanoparticle-containing polymer brush (combo of T-SCNP) before and after the reaction during the preparation of Sample 1 in the embodiments of the present application.

[0064] As shown in Figure 6 , the peak positions are almost the same before and after the grafting reaction, and the relative intensity of the peaks changes slightly. During the formation of the single-stranded polymer nanoparticle-containing polymer brush (combo of T-SCNP), the disappearance of peak a (10.08 ppm) corresponding to the hydrogen protons of the -CHO- group of F-SCNP is observed. In addition, new peaks b' and c' corresponding to the hydrogen protons of the acylhydrazone bond -CH=NH- (11.08 ppm) and NH (8.05 ppm) groups can be observed in the single-stranded polymer nanoparticle-containing polymer brush (combo of T-SCNP).

[0065] Figure 7 is a graph of the particle size distribution of the single-stranded polymer nanoparticle-containing polymer brush (combo of T-SCNP) before and after the reaction during the preparation of Sample 1 in the embodiments of the present application.

[0066] As shown in Figure 7 , the dynamic light scattering (DLS) results show a transition from two peaks to a single peak with a broader size distribution after the reaction, indicating that the two components in the solution become one component.

[0067] Figure 8 is a graph of the SEC elution profile of the single-stranded polymer nanoparticle-containing polymer brush (combo of T-SCNP) before and after the reaction during the preparation of Sample 1 in the embodiments of the present application.

[0068] As shown in Figure 8As shown, the SEC curves before and after the grafting reaction show a transition from two distinct peaks (corresponding to T-SCNPs and high molecular weight linear polymers (H-LPs)) to a single peak, although the molecular weight distribution is significantly broader.

[0069] The present test example also employs Diffusing Wave Spectroscopy (DWS) to analyze the rheological behavior of the single-chain polymer nanoparticle-containing polymer brush (comb of T-SCNPs) of Sample 1, by placing the reaction system of step S40 of the example in a DWS test cell, while adding tracer particles TiO2, and testing the autocorrelation function thereof in solution.

[0070] DWS has a shear frequency of up to 107rad / s, and can provide useful information about the microstructure through Brownian tracer particles in a static polymer solution, according to the following principle:

[0071] According to the velocity autocorrelation function (Equation 1 below) of the Brownian particles, the mean square displacement Δr of the particles can be numerically calculated 2 (Equation 2 below); according to the correlation equation, the viscoelastic information of the polymer can be further obtained.

[0072]

[0073] wherein g2(t) is the autocorrelation function; L is the sample cell thickness (mm); l * is the sample transport mean free path of scattered light (nm); k0 is the diffusion coefficient of the tracer particles, k0 = 2π / λ, wherein λ is the laser wavelength (nm); δ is the amplitude of the motion of the tracer particles; τ is the lag time (s); D0 is the local diffusion coefficient; α is the slope of the curve in a short time; β is the slope of the curve in a long time; D m is the macroscopic diffusion coefficient.

[0074] Figure 9 is the autocorrelation function curve of the single-chain polymer nanoparticle-containing polymer brush (comb of T-SCNPs) of Sample 1 prepared in the example of the present application.

[0075] As Figure 9 shown, the autocorrelation function (ICF) curves of the single-chain polymer nanoparticle-containing polymer brush (comb of T-SCNPs) of Sample 1 and H-LPs show a rapid decay from 1 to 0, indicating complete chain relaxation. A significant increase in the relaxation rate is observed in the single-chain polymer nanoparticle-containing polymer brush (comb of T-SCNPs) system, indicating a decrease in the entangled chains in the system.

[0076] Figure 103 is a graph showing the change in modulus of a polymer brush containing single-chain polymer nanoparticles (combof T-SCNP) of sample 1 prepared in an embodiment of the present invention over time.

[0077] like Figure 10 As shown in Figure 3, the loss modulus of the polymer brush system containing single-chain polymer nanoparticles (comb of T-SCNP) is significantly reduced due to the reduced entanglement between molecular chains.

[0078] Figure 11 1 is a graph showing the change in viscosity of a polymer brush containing single-chain polymer nanoparticles (combof T-SCNP) in a solution in preparation of sample 1 in an embodiment of the present invention over time.

[0079] like Figure 11 As shown in Figure 3, the polymer brushes containing single-chain polymer nanoparticles (comb of T-SCNP) exhibited lower zero-shear viscosity in solution due to the reduced entanglement between the molecular chains.

[0080] Figure 12 1 is a relaxation time diagram of a polymer brush containing single-chain polymer nanoparticles (combof T-SCNP) prepared in solution in Sample 1 in an embodiment of the present invention.

[0081] like Figure 12 As shown, the introduction of single-chain polymer nanoparticles into the system increases the distance between polymer chains, thereby accelerating the relaxation rate of the chain segments.

[0082] Functions and Effects of the Embodiments

[0083] Unlike existing NPs, single-chain nanoparticles (SCNPs) possess unique cross-linked nanodomains, which enable them to exhibit properties distinct from those of other polymeric nanoparticles, such as macrocycles, dendrimers, branched polymers, and inorganic nanoparticles. Thanks to improvements in controlled polymerization techniques and synthetic strategies, the structure and size of SCNPs (≥5 nm) can be effectively controlled by adjusting the type and number of reactive side groups in the linear precursors.

[0084] Since the grafted units of the polymer brush of this embodiment are single-chain nanoparticles with specific size and structure, unlike traditional grafted linear polymers, single-chain nanoparticles can increase the distance between the main chains to reduce the viscosity of the system, and therefore exhibit different properties in solution from traditional polymer brushes.

[0085] According to the above examples and test examples, it can be seen that the T-SCNP containing active end groups is grafted into the H-LP main chain through acylhydrazone chemical reaction, and the obtained comb of T-SCNP shows unique performance in solution, such as reducing the molecular chain entanglement of the system, accelerating the chain segment relaxation time and reducing the system viscosity.

[0086] Therefore, the special topological structure polymer has great potential in the field of viscosity regulators and surfactants.

[0087] In addition, the present application determines the microstructure of the polymer in solution (i.e. mesh size (ξ), terminal relaxation time (TR) and viscoelastic properties (i.e. shear storage / loss modulus)) by using micro-rheological technology, and DWS has excellent sensitivity and can characterize the rheological properties of the polymer solution in a wide frequency range (0-107 rad / s), which cannot be achieved by traditional rheological instruments.

[0088] Those skilled in the art should understand that the present application is not limited to the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application, and various changes and improvements can be made without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a polymer brush containing single-chain polymer nanoparticles, characterized in that: The following steps are involved: S10, using any two to four of methyl methacrylate, 2-(acetoacetoxy)ethyl methacrylate, furfuryl methacrylate, maleimide-functionalized methacrylate, or anthracenyl methacrylate as monomers to synthesize a linear polymer containing active end groups; S20, subjecting the linear polymer containing active end groups to an intramolecular cross-linking reaction to obtain single-chain intramolecular cross-linked polymer nanoparticles containing active end groups; S30, using methyl methacrylate and methacrylic acid hydrazide as monomers, prepares high molecular weight linear polymers containing reactive side groups by free radical polymerization; S40, grafting the single-chain internally cross-linked polymer nanoparticles containing active end groups to the high molecular weight linear polymer containing active side groups through a grafting reaction to prepare the polymer brush containing the single-chain polymer nanoparticles.

2. The method for preparing a polymer brush containing single-chain polymer nanoparticles according to claim 1, characterized in that: in, Step S10 includes the following sub-steps: S11, adding any two to four of methyl methacrylate, 2-(acetoacetoxy)ethyl methacrylate, furfuryl methacrylate, maleimide-functionalized methacrylate, or anthracenyl methacrylate, an initiator, and a ligand into a polymerization reaction bottle, and then applying vacuum for a predetermined time; S12, adding a catalyst, continuing vacuuming and deoxygenation, and then heating the reaction to obtain a first pre-product; S13, dissolving the first pre-product in ethyl acetate, and then dropping the solution into ethanol for precipitation to obtain a precipitated first polymer; S14, drying the first polymer to a constant weight to obtain the linear polymer containing active end groups.

3. The method for preparing a polymer brush containing single-chain polymer nanoparticles according to claim 2, characterized in that: in, In step S11, the initiator is an ATRP initiator, In step S12, the catalyst is CuBr and the ligand is PMDETA.

4. The method for preparing a polymer brush containing single-chain polymer nanoparticles according to claim 1, wherein: in, Step S20 includes the following sub-steps: S21, dissolving the linear polymer containing active end groups in an excess amount of solvent to obtain a very dilute solution; S22, reacting the raw materials in the extremely dilute solution, and removing the solvent after the reaction to obtain a primary product; S23, adding the primary product into methanol to obtain the single-chain intra-crosslinked polymer nanoparticles containing active end groups.

5. The method for preparing a polymer brush containing single-chain polymer nanoparticles according to claim 4, characterized in that: in, In step S21, the solvent in the extremely dilute solution includes THF or DMF, and the concentration of the linear polymer containing active end groups in the extremely dilute solution is not higher than 1 g / L. In step S22, the reaction method is to place it in a UV reactor for ultraviolet irradiation reaction or direct heating reaction for 24 hours. When ultraviolet irradiation reaction is used, the light wavelength is 360nm. When it is a direct heating reaction, the heating method is to slowly heat up to 120°C and react, and then slowly cool down to room temperature.

6. The method for preparing a polymer brush containing single-chain polymer nanoparticles according to claim 1, wherein: in, Step S30 includes the following sub-steps: S31, adding methyl methacrylate, methacrylic acid hydrazide and an initiator into a polymerization reaction bottle, evacuating the bottle for a predetermined time, and then heating the bottle for reaction to obtain a second pre-product; S32, dissolving the second pre-product in ethyl acetate, and then dropping the solution into ethanol for precipitation to obtain a precipitated second polymer; S33, drying the second polymer to a constant weight to obtain the high molecular weight linear polymer containing reactive side groups.

7. The method for preparing a polymer brush containing single-chain polymer nanoparticles according to claim 6, characterized in that: in, In step S31, the molar ratio of methyl methacrylate to methacrylic acid hydrazide is 7:

3. Initiators include azobisisobutyronitrile.

8. The method for preparing a polymer brush containing single-chain polymer nanoparticles according to claim 1, wherein: in, Step S40 includes the following steps: S41, adding the single-chain cross-linked polymer nanoparticles containing active end groups and the high molecular weight linear polymer containing active side groups into a solvent for reaction; S42, after the reaction is completed, the reaction solution is dropped into ethanol for precipitation to obtain a third polymer; S43, drying the third polymer to a constant weight to obtain the polymer brush containing single-chain polymer nanoparticles.

9. The method for preparing a polymer brush containing single-chain polymer nanoparticles according to claim 8, characterized in that: in, In step S41, the feed weight ratio of the single-chain cross-linked polymer nanoparticles containing active end groups to the high molecular weight linear polymer containing active side groups is 3:

7. Solvents included DMF.

10. A polymer brush containing single-chain polymer nanoparticles, characterized in that: Prepared by the method for preparing a polymer brush containing single-chain polymer nanoparticles according to any one of claims 1 to 9, Among them, in the system of the polymer brush containing single-chain polymer nanoparticles, the chain entanglement between the molecular chains is less, the viscosity of the system is lower, the chain relaxation rate is faster, and the grid size between the entangled chains is larger. The polymer brush containing single-chain polymer nanoparticles is used as a viscosity regulator or a surfactant.

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