Water-based polymer nano material as well as preparation method and application thereof

Abstract

The invention provides a water-based polymer nano material as well as a preparation method and application thereof, and belongs to the technical field of nano materials. The preparation method of the water-based polymer nano material comprises the following steps: a hydrophilic monomer M1 is subjected to an active polymerization reaction in the presence of a compound A ', a water-soluble polymer P1-A is obtained, P1 is a water-soluble polymer main chain formed by a hydrophilic monomer M1 unit, and A is an active terminal formed by the compound A'; the water-soluble polymer P1-A and a monomer M2 are subjected to a polymerization reaction to obtain an amphiphilic block polymer P1-b-P2-A, and P2 is a hydrophobic block formed by a monomer M2 unit; in a water phase, an amphiphilic block polymer P1-b-P2-A is taken as a micelle seed, a hydrophobic monomer M3 is added, seed emulsion polymerization induced self-assembly is carried out in the presence of an initiator, and the water-based polymer nano material is obtained.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of nanomaterials, and particularly relates to a water-based polymer nanomaterial, a preparation method and application thereof. BACKGROUND

[0002] Polymer nanomaterials have great application potential in the fields of biomedicine, nanoreactors, coatings and biomineralization. Polymerization-induced self-assembly (PISA) has become a highly efficient and reliable method for preparing polymer nanomaterials, which can be used to directionally synthesize polymer nanomaterials under high concentration (50 wt%) and mild conditions. The successful implementation of PISA usually relies on controllable / active polymerization technology, such as reversible addition-fragmentation chain transfer (RAFT) polymerization. PISA can be carried out in various solvents (such as water, polar organic solvents or non-polar organic solvents), and water-based PISA is more attractive due to its green and environmentally friendly and economical characteristics. However, water-based PISA is generally carried out in the form of water-based dispersion polymerization or water-based emulsion polymerization (depending on the water solubility of the monomer), which has strict standards for monomers, i.e., the monomer has good hydrophilicity, and the polymer formed by polymerization of the monomer is hydrophobic, and only a few monomers meet the above standards, which severely limits the chemical diversity of water-based nanomaterials and further application.

[0003] Compared with water-based dispersion PISA, emulsion polymerization-induced self-assembly is suitable for a wider range of monomers. However, traditional water-based emulsion polymerization-induced self-assembly (TE-PISA) still has some serious problems, such as limited morphology transformation of polymer nanomaterials, easy production of large aggregates, poor repeatability of polymer nanomaterials, and very unfavorable further application of the obtained water-based nanomaterials. Therefore, there is an urgent need for a reliable method to solve the problems of TE-PISA in preparing water-based polymer nanomaterials. SUMMARY

[0004] In view of the above technical problems, the present application provides a water-based polymer nanomaterial, a preparation method and application thereof, so as to at least partially solve the above technical problems. In this regard, the technical solutions provided by the present application are as follows.

[0005] As a first aspect of the present application, a preparation method of a water-based polymer nanomaterial is provided, comprising steps A1-A3.

[0006] Step A1: performing active polymerization reaction of a hydrophilic monomer M1 in the presence of a compound A', to obtain a water-soluble polymer P1-A, wherein P1 is a water-soluble polymer backbone formed by hydrophilic monomer M1 units, and A is an active end formed by the compound A'.

[0007] Step A2: a polymerization reaction of the water-soluble polymer P1-A and the monomer M2 is performed to obtain an amphiphilic block polymer P1-b-P2-A, wherein P2 is a hydrophobic block formed by monomer M2 units.

[0008] Step A3: seed emulsion polymerization induced self-assembly is performed in an aqueous phase, with the amphiphilic block polymer P1-b-P2-A as a micellar seed, and the addition of a hydrophobic monomer M3 in the presence of an initiator, to obtain a water-based polymer nanomaterial.

[0009] wherein the hydrophilic monomer M1 is selected from any one of a (meth)acrylamide monomer, a (meth)acrylate monomer, and methacrylic acid; and the monomer M2 and / or the hydrophobic monomer M3 is each independently selected from any one of a (meth)acrylamide monomer, a (meth)acrylate monomer, and styrene.

[0010] In the technical solution of the present application, the water-soluble polymer P1-A is prepared by using the hydrophilic monomer M1 and the compound A' (initiator or chain transfer agent), the active end A in the aqueous polymer can continue to polymerize with the monomer M2, and the obtained amphiphilic block polymer P1-b-P2-A is both a macromolecular chain transfer agent / initiator and a micellar seed; the hydrophobic monomer M3 penetrates into the micellar seed through aqueous phase diffusion, so that the macromolecular initiator / chain transfer agent synchronously chain-extends, thereby making the emulsion polymerization have good controllability, and realizing the controllable morphology transformation, which is convenient for the directional synthesis of nanomaterials with different morphologies (such as spherical, worm-shaped, and vesicular nanomaterials). The method of pre-constructing the micellar seed can also effectively inhibit the generation of large aggregates, and the obtained polymer nanomaterial has good repeatability. In addition, the technical solution provided by the present application is also applicable to different macromolecular initiators / chain transfer agents and hydrophobic monomers M3, and has good universality.

[0011] In some embodiments, in step A1, the active polymerization reaction of the hydrophilic monomer M1 and the compound A' in the presence of an initiator includes: an active polymerization reaction of the hydrophilic monomer M1 and the compound A' in the presence of an initiator to obtain a water-soluble polymer P1-A, wherein the active polymerization reaction is selected from any one of an atom transfer radical polymerization reaction, a reversible addition-fragmentation chain transfer polymerization reaction, and a stable free radical polymerization reaction.

[0012] In some embodiments, when the active polymerization reaction is an atom transfer radical polymerization (ATRP), the active end A is a halogen atom. The mechanism of atom transfer radical polymerization can be understood as follows: an organic halide initiator initiates the radical polymerization of the hydrophilic monomer M1 to obtain P1-A, wherein the compound A' is an organic halide initiator, which can be selected from halogenated alkane, benzyl halide, a-brominated ester, a-halogenated ketone, a-halogenated nitrile, etc., such as a-brominated benzyl alkane (EBiB) and the like; and the active end A is a halogen.

[0013] In some embodiments, when the active polymerization reaction is a reversible addition-fragmentation chain transfer polymerization (RAFT), the active end A is a chain transfer agent, wherein the chain transfer agent (i.e. RAFT agent) is selected from at least one of a trithioester, a dithioester, a dithiourethane, a xanthate. The core mechanism of reversible addition-fragmentation chain transfer polymerization (RAFT) is to establish a dynamic balance between active species and dormant species through reversible addition-fragmentation reactions between chain transfer agents (RAFT agents) and active radicals, thereby achieving controllability of polymerization. For example: the primary radical generated by the decomposition of the initiator (azobisisobutyronitrile, AIBN) reacts with the hydrophilic monomer M1 to generate a monomer radical (i.e. active species). The growing polymer chain radical undergoes addition with the RAFT agent to form an unstable intermediate radical. The intermediate radical rapidly breaks down to generate two products: one is a new chain radical (R· from the R group of the RAFT agent), which can continue to initiate monomer polymerization; the other is a dormant species temporarily losing activity. The newly generated chain radical will again undergo addition-fragmentation reaction with the dormant species to regenerate the original chain radical and a new dormant species. Through this reversible process, the concentration of active radicals in the system is maintained at a low level, significantly inhibiting the double radical termination reaction.

[0014] In some embodiments, when the active polymerization reaction is a stable free radical polymerization (SFRP), the active end A is any one of an alkoxyamine, a triazolinyl group, and an arylazole group. The core principle of stable free radical polymerization is to control the concentration of free radicals by reversible combination between stable radicals and active chain radicals to form dormant species, thereby achieving controllability of polymerization. Specifically, the free radical initiator (such as peroxide, azo compound) decomposes to generate radicals and initiates the polymerization of the hydrophilic monomer M1 to form an active chain radical. The stable radical (such as a compound containing an alkoxyamine, i.e. compound A') added reacts with the active chain radical to form a covalently linked dormant species. The dormant species can be decomposed under heat or other conditions to release active chain radicals and stable radicals again, so that the active species and the dormant species are in dynamic balance.

[0015] In some embodiments, in step A1, specifically the hydrophilic monomer M1 is selected from at least one of N-(2-hydroxypropyl) methacrylamide, polyethylene glycol methacrylate, methacrylic acid.

[0016] In some embodiments, in step A2, the molar ratio of the water-soluble polymer P1-A to the monomer M2 is 1:10-100, for example, can be 1:10, 1:20, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80, 1:90, 1:100, etc., preferably 1:30, which is advantageous for forming micellar seeds within this range.

[0017] In some embodiments, in step A2-step A3, the monomer M2 has hydrophilicity or hydrophobicity, but its polymerization forms a hydrophobic polymer segment. Therefore, in the case where the monomer M2 has hydrophilicity, the monomer M2 and the hydrophobic monomer M3 are different; in the case where the monomer M2 has hydrophobicity, the monomer M2 and the hydrophobic monomer M3 are the same or different. Further, the monomer M2 is selected from at least one of diacetone acrylamide, 2-hydroxypropyl methacrylate, 2-(diisopropylamino)ethyl methacrylate, benzyl methacrylate, glycidyl methacrylate, styrene; the hydrophobic monomer M3 is selected from at least one of benzyl methacrylate, 2-(diisopropylamino)ethyl methacrylate, glycidyl methacrylate, styrene. The SE-PISA provided by the present application can meet different hydrophobic monomers and has good universality.

[0018] As a second aspect of the present application, a water-based polymer nanomaterial prepared by the preparation method described above is provided.

[0019] In the technical solution of the present application, compared with the traditional TE-PISA method, the SE-PISA preparation method of the present application can obtain polymer nanomaterials with controllable morphology, uniform dispersion, high stability and higher quality, and has good universality.

[0020] In some embodiments, the solid content of the water-based polymer nanomaterial is 5-50wt%.

[0021] As a third aspect of the present application, a water-based polymer nanomaterial is provided for toughening and reinforcing, wherein the application comprises: the water-based polymer nanomaterial as a reinforcing agent for toughening and reinforcing elastomers or hydrogels.

[0022] In the technical solution of the present application, because the water-based polymer nanomaterial of the present application is uniformly dispersed and no large aggregates exist, the application of the water-based polymer nanomaterial with good quality and uniform dispersion to elastomers or hydrogels can effectively reduce the generation of stress defects, realize the toughening and reinforcing of the elastomers or hydrogels, and improve the mechanical properties thereof. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 A schematic diagram of the preparation of water-based polymer nanomaterials for traditional TE-PISA and SE-PISA of the present application;

[0024] Figure 2 A schematic diagram of the preparation of POEGMA 19 -PETTC by 1H NMR (A) and gel permeation chromatography (GPC) (B); 1 1 H NMR (A) and GPC (B);

[0025] Figure 3 A schematic diagram of the preparation of POEGMA 19 -b-PSt 16 -PETTC by 1H NMR (A) and GPC (B); 1 1 H NMR (A) and GPC (B);

[0026] Figure 4 A schematic diagram of the SE-PISA of St monomer regulated by POEGMA 19 -b-PSt 16 -PETTC as a macro-chain transfer agent (also a micellar seed) and the test result graph thereof, wherein A is a polymerization schematic diagram, B is a polymerization kinetics tracking graph, C is a GPC curve graph of the polymer obtained at different polymerization times, D is a UV-Vis absorption spectrum graph of the solution before and after polymerization, and the PETTC end group retention rate (R 19 ) calculated therefrom, F is a dynamic light scattering (DLS) graph of the nanoparticles obtained by SE-PISA, and G is a transmission electron microscope (TEM) graph; 350 PETTC

[0027] Figure 5 A schematic diagram of the TE-PISA of St monomer regulated by POEGMA 19 -PETTC as a macro-chain transfer agent and the test result graph thereof, wherein A is a polymerization schematic diagram, B is a polymerization kinetics tracking graph, C is a GPC curve graph of the polymer obtained at different polymerization times, D is a DOSY NMR spectrum graph of the polymer obtained after polymerization, E is a UV-Vis absorption spectrum of the solution before and after polymerization, and the PETTC end group retention rate (R PETTC ) calculated therefrom, F is a DLS graph of the nanoparticles obtained by SE-PISA, and G is a TEM graph; ​​​​

[0028] Figure 6 It is POEGMA 19 -b-PSt 16 -PETTC acts as a macromolecular chain transfer agent (and also a micelle seed) to regulate the SE-PISA of St monomers at different DPs. PSt The following are microscopic and physical images of the obtained nanoparticles, where A is a TEM image, B is a physical image of the polymer nanomaterial dispersion, and C is a physical image of the dispersion sample after being placed upside down for 1 month.

[0029] Figure 7 It is POEGMA 19 -PETTC is a macromolecular chain transfer agent that regulates the St monomer for TE-PISA, at different DP... PSt The following are microscopic and physical images of the obtained nanoparticles, where A is a TEM image, B is a physical image of the polymer nanomaterial dispersion, and C is a physical image of the dispersion sample after being placed for 1 day and then inverted.

[0030] Figure 8 For POEGMA 19 -b-PDIPEMA 29 -PETTC 1 H NMR spectrum and GPC spectrum, where A is 1 H NMR spectrum, B is GPC spectrum;

[0031] Figure 9 It is POEGMA 19 -b-PDIPEMA 29 - This graph shows the SE-PISA results of DIPEMA monomer regulated by PETTC, a macromolecular chain transfer agent (and also a micelle seed). A represents the polymerization kinetics tracking graph; B represents the GPC curves of polymers obtained at different polymerization times; and C represents the UV-Vis absorption spectra of the solutions before and after polymerization, along with the calculated PETTC end-group retention rate (R0). PETTC D is a TEM image of the obtained nanoparticles; E is a physical image of the obtained polymer nanomaterial dispersion; F is a physical image of the bottom of the inverted sample tube after the dispersion sample has been placed for 1 month.

[0032] Figure 10 It is POEGMA 19 -PETTC was used as a macromolecular chain transfer agent to regulate the DIPEMA monomer in TE-PISA. A shows the monomer conversion rate (i.e., polymerization kinetics tracking) graph; B shows the GPC curves of polymers obtained at different polymerization times; C shows the UV-Vis absorption spectra of the solutions before and after polymerization, and the calculated PETTC end-group retention rate (R0). PETTCD is a TEM image of the obtained nanoparticles, E is a physical image of the obtained polymer nanomaterial dispersion, and F is a physical image of the bottom of the inverted sample tube after the dispersion sample has been placed for 1 day.

[0033] Figure 11 It is POEGMA 19 -b-PDIPEMA 29 -PETTC acts as a macromolecular chain transfer agent (and also a micelle seed) to regulate DIPEMA monomers for SE-PISA, at different DIPEMA levels. PDIPEMA The following are microscopic and physical images of the obtained nanoparticles, where A is a TEM image of the nanoparticles, B is a physical image of the polymer nanomaterial dispersion, and C is a physical image of the bottom of the sample tube after the dispersion sample has been placed for 1 month and then inverted.

[0034] Figure 12 It is POEGMA 19 -PETTC is a macromolecular chain transfer agent that regulates the DIPEMA monomer for TE-PISA, at different DIPEMA... PDIPEMA The following are microscopic and physical images of the obtained nanoparticles, where A is a TEM image of the nanoparticles, B is a physical image of the polymer nanomaterial dispersion, and C is a physical image of the bottom of the sample tube after the dispersion sample has been placed for 1 day and then inverted.

[0035] Figure 13 For POEGMA 19 -b-PBzMA 21 -PETTC 1 H NMR spectrum and GPC spectrum, where A is 1 B is the H NMR spectrum, and B is the GPC spectrum;

[0036] Figure 14 It is POEGMA 19 -b-PBzMA 21 -PETTC acts as a macromolecular chain transfer agent (and also a micelle seed) to regulate BzMA monomers for SE-PISA, at different DP... PBzMA The following are microscopic and physical images of the obtained nanoparticles, where A is a TEM image of the nanoparticles, B is a physical image of the polymer nanomaterial dispersion, and C is a physical image of the bottom of the sample tube after the dispersion sample has been placed for 1 month and then inverted.

[0037] Figure 15 It is POEGMA 19 -PETTC is a macromolecular chain transfer agent that regulates the BzMA monomer for TE-PISA, at different DP... PBzMA The following are microscopic and physical images of the obtained nanoparticles, where A is a TEM image of the nanoparticles, B is a physical image of the polymer nanomaterial dispersion, and C is a physical image of the bottom of the sample tube after the dispersion sample has been placed for 1 day and then inverted.

[0038] Figure 16 It is POEGMA 19 -b-PDIPEMA 29 -PETTC acts as a macromolecular chain transfer agent (and also a micelle seed) to regulate the SE-PISA of St monomers at different DPs. PSt The following are microscopic and physical images of the obtained nanoparticles, where A is a TEM image of the nanoparticles, B is a physical image of the polymer nanomaterial dispersion, and C is a physical image of the bottom of the inverted sample tube after the dispersion sample has been placed for 1 month.

[0039] Figure 17 For PHPMAm 27 -PETTC 1 H NMR spectrum and GPC spectrum, where A is 1 B is the H NMR spectrum, and B is the GPC spectrum;

[0040] Figure 18 For aqueous synthesis of PHPMAm 27 -b-PDIPEMA 25 The solution obtained after the polymerization of -PETTC 1 H NMR spectrum and GPC spectrum, where A is 1 H NMR spectrum, B is the obtained PHPMAm 27 -b-PDIPEMA 25 -PETTC's GPC plot;

[0041] Figure 19 It is PHPMAm 27 -b-PDIPEMA 25 -PETTC acts as a macromolecular chain transfer agent (and also a micelle seed) to regulate the SE-PISA of St monomers at different DPs. PSt The following are microscopic and physical images of the obtained nanoparticles, where A is a TEM image of the nanoparticles, B is a physical image of the polymer nanomaterial dispersion, and C is a physical image of the bottom of the inverted sample tube after the dispersion sample has been placed for 1 month.

[0042] Figure 20 It is PHPMAm 27 -PETTC is a macromolecular chain transfer agent that regulates the St monomer for TE-PISA, at different DP... PSt The following are microscopic and physical images of the obtained nanoparticles, where A is a TEM image of the nanoparticles, B is a physical image of the polymer nanomaterial dispersion, and C is a physical image of the bottom of the inverted sample tube after the dispersion sample has been placed for 1 day.

[0043] Figure 21 Example 8 uses SE-PISA to prepare PHPMAm27 -b-PDIPEMA 25 -b-PSt 55 TEM images of the obtained nanomaterials, B are DLS images, C are photographs of the obtained polymer nanomaterial dispersion liquid, and D are photographs of the bottom of the inverted sample tube after the dispersion liquid sample was placed for 1 month;

[0044] Figure 22 PHPMAm prepared in Example 8 27 -b-PDIPEMA 25 -b-PSt 55 Polymer GPC curve of the experiment of the nanomaterials repeated 5 times under the same conditions;

[0045] Figure 23 PHPMAm prepared in Comparative Example 7 using the TE-PISA strategy 27 -b-PSt 80 TEM images of the obtained nanomaterials, B are DLS images, C are photographs of the obtained polymer nanomaterial dispersion liquid, and D are photographs of the bottom of the inverted sample tube after the dispersion liquid sample was placed for 1 day;

[0046] Figure 24 PHPMAm prepared in Comparative Example 7 27 -b-PSt 80 Polymer GPC curve of the experiment of the nanomaterials repeated 5 times under the same conditions;

[0047] Figure 25 Stress-strain curve of the PVA film prepared without the nanomaterials;

[0048] Figure 26 PHPMAm in Application Example 1 27 -b-PDIPEMA 25 -b-PSt 55 Stress-strain curves of the PVA composite materials prepared by mixing the nanomaterials with PVA uniformly, respectively;

[0049] Figure 27 PHPMAm prepared in Comparative Application Example 1 using the TE-PISA strategy 27 -b-PSt 80 Stress-strain curves of the PVA composite materials prepared by mixing the nanomaterials with PVA uniformly, respectively. DETAILED DESCRIPTION

[0050] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings. It should be understood, however, that the description is merely exemplary and is not intended to limit the scope of the present application. In the following detailed description of embodiments of the application, numerous specific details are set forth in order to provide a thorough understanding of the embodiments. However, it will be apparent to one skilled in the art that one or more embodiments can be practiced without these specific details. In other instances, well-known structures and functions have not been described in detail in order to avoid obscuring aspects of the application.

[0051] Figure 1 A comparison diagram of water-based polymer nanomaterials prepared by conventional TE-PISA and SE-PISA of the present application.

[0052] As shown in Figure 1 , the conventional TE-PISA uses a water-soluble macromolecular chain transfer agent to directly regulate the emulsion polymerization-induced self-assembly of a hydrophobic monomer. This method cannot achieve sufficient and equal contact between the water-soluble macromolecular chain transfer agent and the hydrophobic monomer because they are in two phases, resulting in different step-growth of the macromolecular chain transfer agent / initiator, making the emulsion polymerization uncontrollable, showing uncontrollable morphology of the nanomaterial, easy production of large aggregates during polymerization, precipitation after a period of storage, and poor repeatability of the nanomaterial preparation.

[0053] However, the present application uses a method of pre-constructing micellar seeds, which ensures that most of the macromolecular chain transfer agent / initiator (also micellar seeds) has sufficient and equal contact probability with the hydrophobic monomer M3, so that the macromolecular chain transfer agent can have synchronous step-growth, thereby making the emulsion polymerization have good controllability, showing controllable morphology of the nanomaterial (can be directionally prepared nanomaterials without morphology), effectively inhibiting the production of large aggregates, uniformly dispersed after a period of storage, and high repeatability of the nanomaterial preparation.

[0054] Hereinafter, the preparation of water-based polymer nanomaterials by TE-PISA and SE-PISA and their properties will be described in detail in conjunction with specific examples. The reagents in the following examples and comparative examples can be commercially purchased or prepared by the methods provided below.

[0055] Example 1

[0056] The macromolecular RAFT reagent POEGMA-PETTC was synthesized by dissolving methoxy-oligoethylene glycol methacrylate (OEGMA, 24 g, 50 mmol), 4-cyano-4-(((phenylethylthio)thiocarbonyl)thio)valeric acid (PETTC, 678 mg, 2 mmol), and azobisisobutyronitrile (AIBN, 33 mg, 0.2 mmol) in 25 mL of tetrahydrofuran and adding it to a 100 mL polymerization flask. After three freeze-vacuum-thaw cycles, the polymerization tube was sealed and the reaction was stirred in an oil bath at 70 °C for 5 h. The crude product was precipitated three times in n-hexane and dried to obtain a yellow solid product.

[0057] The proton NMR spectrum of the obtained macromolecular RAFT reagent ( 1 H NMR) such as Figure 2 As shown in Figure A, the calculated degree of polymerization is 19, therefore the macromolecular RAFT reagent is labeled as POEGMA. 19 -PETTC. Furthermore, POEGMA 19 -PETTC gel permeation chromatography (GPC) data as follows Figure 2 As shown in Figure B.

[0058] RAFT reagent for synthesizing diblock polymer macromolecules: POEGMA 19 PETTC (1.90 g, 0.2 mmol), styrene (St, 1.25 g, 12 mmol), and AIBN (3 mg, 0.02 mmol) were dissolved in 5 mL of N,N-dimethylformamide (DMF) and added to a 10 mL polymerization flask. After three freeze-vacuum-thaw cycles, the polymerization tube was sealed and the reaction was stirred in an oil bath at 70 °C for 12 h. The crude product was precipitated three times in diethyl ether and dried to obtain a yellow solid product.

[0059] The proton NMR spectrum of the obtained diblock polymer macromolecule RAFT reagent ( 1 H NMR) such as Figure 3 As shown in Figure A, the degree of polymerization of polystyrene (PSt) was calculated to be 16, and it was labeled as POEGMA. 19 -b-PSt 16 -PETTC;POEGMA 19 -b-PSt 16 -PETTC gel permeation chromatography (GPC) data as follows Figure 3 As shown in Figure B.

[0060] Seed emulsion polymerization-induced self-assembly (SE-PISA) polymerization kinetics tracking: using POEGMA 19 -b-PSt 16PETTC is a macro-chain transfer agent (also a micelle seed) to control the styrene (St) monomer for aqueous phase seed emulsion polymerization induced self-assembly, the solid content (the mass percentage of the target polymer in the reaction system) of the reaction system is 15wt%, and the polymerization process of polystyrene with a target polymerization degree DP PSt =350 is as shown in Figure A of Figure 4 .

[0061] The specific preparation method is: POEGMA 19 -b-PSt 16 -PETTC (555 mg, 5 x 10 -2 mmol), St (1740 mg, 16.7 mmol), azobiscyanovaleic acid (ACVA) (2.8 mg, 10 -2 mmol), water (13.0 g) and a magnetic stirrer are added to a polymerization tube (in order to reduce the error in the weighing process of ACVA, ACVA is first dissolved in water to make the final content of ACVA 0.1wt%, and then 2800 mg of the above ACVA aqueous solution is taken and added to the polymerization tube. In all subsequent synthesis experiments, ACVA is added to the reaction mixture in this way). After three cycles of freezing-vacuumizing-thawing, the polymerization tube is sealed. Then the polymerization tube is placed in a 70°C oil bath and stirred for polymerization. 1 mL of the reaction mixture is taken out at different reaction times for monomer conversion and polymer GPC characterization. The test results show that the polymerization induction period disappears (Figure B of Figure 4 , indicating that the macro-chain transfer agent undergoes synchronous chain growth (Figure C of Figure 4 ). DOSY NMR results show that pure POEGMA 19 -b-PSt 350 block polymer (such as Figure 4 Figure D of Figure 4 ). UV-Vis results show that after the reaction is completed, there is still a very high retention rate of PETTC end groups (Figure E of Figure 4 ). DLS and TEM results show that uniform size distribution of porous vesicles is obtained without the generation of large aggregates (such as Figure F and Figure G of Figure 4 ). These data show that the SE-PISA strategy makes the macro-chain transfer agent (i.e. micelle seed) undergo synchronous chain growth, thereby making the emulsion polymerization have good controllability, making the obtained polymer nanomaterial have good controllability, and effectively inhibiting the generation of large aggregates.

[0062] Comparative Example 1

[0063] Traditional emulsion polymerization induced self-assembly (TE-PISA) polymerization kinetics tracking: POEGMA 19PETTC is used as a macro-chain transfer agent to regulate the emulsion polymerization of styrene (St) monomer to induce self-assembly, the solid content (mass percentage of target polymer in the reaction system) of the reaction system is 15wt%, and the polymerization process of polystyrene with a target polymerization degree DP PSt =350 is shown in Figure A of Figure 5 .

[0064] Specifically, the preparation method is: POEGMA 19 -PETTC (475 mg, 5 x 10 -2 mmol), St (1820 mg, 17.5 mmol), azobis cyanovaleric acid (ACVA, 2.8 mg, 10 -2 mmol), water (13.0 g) and a magnetic stirrer are added to a polymerization tube. After three cycles of freezing-vacuumizing-thawing, the polymerization tube is sealed. Then the polymerization tube is placed in a 70°C oil bath for stirring to carry out the polymerization reaction. 1 mL of the reaction is taken out at different reaction times for monomer conversion rate and polymer GPC characterization, and the test results show that the polymerization has a clear induction period and a nucleation-induced polymerization acceleration phenomenon (as shown in Figure B of Figure 5 ); the macro-chain transfer agent does not undergo synchronous chain growth (as shown in Figure C of Figure 5 ): the nucleated macro-chain transfer agent has a faster chain growth rate due to sufficient contact with St monomer, and the macro-chain transfer agent in the solution has a slower chain growth rate due to insufficient contact with St monomer, and the macro-chain transfer agent gradually nucleates during the polymerization process, thereby leading to uncontrollable emulsion polymerization. DOSY NMR results show that there is still a part of the macro-chain transfer POEGMA 19 -PETTC does not chain extend to form amphiphilic POEGMA 19 -b-PSt block polymer (as shown in Figure D of Figure 5 ), and UV-Vis results show that there is still a very high PETTC end group retention rate after the reaction (as shown in Figure E of Figure 5 ). DLS and TEM results show that the nanomaterials are unevenly distributed and have large aggregates (as shown in Figures F and G of Figure 5 ). These data show that the root cause of the poor controllability of the TE-PISA system is that the macro-chain transfer agent cannot undergo synchronous chain growth, thereby making the emulsion polymerization less controllable.

[0065] Example 2

[0066] Example 2 uses the same SE-PISA method as in Example 1: POEGMA 19 -b-PSt 16PETTC is the macro-chain transfer agent (also the micelle seed) to control the styrene (St) monomer to induce self-assembly in the process of aqueous phase seed emulsion polymerization, the solid content of the reaction system is 15wt%, and the target polymerization degree DP PSt =150 of polystyrene (POEGMA 19 -b-PSt 150 ) is 150. The process is as follows.

[0067] The preparation method is the same as that of Example 1, except that POEGMA 19 -b-PSt 16 -PETTC (111 mg, 10 - 2 mmol), St (139 mg, 1.34 mmol), azobis cyanovaleric acid (ACVA, 0.56 mg, 2x10 -3 mmol), water (1.42 g) and a magnetic stir bar are added to the polymerization tube to remove oxygen before the polymerization reaction, and the polymerization reaction time is 4 h. The reaction mixture is quickly cooled to room temperature and exposed to air to quench the free radicals to terminate the reaction. At the same time, other DP PSt (DP PSt =200, 250 and 400) of polymer nanomaterials (i.e. POEGMA 19 -b-PSt 200 , POEGMA 19 -b-PSt 250 , POEGMA 19 -b-PSt 400 ) are synthesized by using the SE-PISA strategy. The TEM image of the obtained polymer nanomaterial is shown in A of Figure 6 , and the actual image of the obtained polymer nanomaterial dispersion is shown in B of Figure 6 . After the obtained sample is placed upside down for 1 month, no obvious precipitate is observed at the bottom of the sample tube (as shown in C of Figure 6 ), indicating that no large aggregates are generated in the synthesis process.

[0068] Comparative Example 2

[0069] Comparative Example 2 adopts the same method as Comparative Example 1 for TE-PISA: POEGMA 19 -PETTC is the macro-chain transfer agent to control the styrene (St) monomer to induce self-assembly in the process of emulsion polymerization, the solid content of the reaction system is 15wt%, and the target polymerization degree DP PSt =150 of polystyrene (POEGMA 19 -b-PSt 150 ) is 150. The process is as follows.

[0070] The preparation method is the same as Comparative Example 1, except that POEGMA 19 -PETTC (95 mg, 10 -2 mmol), St (156 mg, 1.5 mmol), azobis cyanovaleric acid (ACVA, 0.56 mg, 2 x 10 -3 mmol), water (1.42 g) and a magnetic stir bar were added to the polymerization tube to remove oxygen before the polymerization reaction, and the reaction time was 4 h. The reaction mixture was quickly cooled to room temperature and exposed to air to quench the free radicals to terminate the reaction. At the same time, other polymer nanomaterials (POEGMA PSt -b-PSt PSt , POEGMA 19 -b-PSt 200 , POEGMA 19 -b-PSt 250 , POEGMA 19 -b-PSt 400 ) of different DPs (DP 19 = 200, 250 and 400) were synthesized using the TE-PISA strategy. The TEM of the obtained polymer nanomaterials is shown in Figure A of Figure 7 , and the actual figure of the dispersion liquid of the obtained polymer nanomaterials is shown in Figure B of Figure 7 . After the obtained sample was placed for 1 day and inverted, a large amount of precipitate at the bottom of the sample tube could be clearly seen (as shown in Figure C of Figure 7 ), indicating that large aggregates were generated during the synthesis.

[0071] POEGMA 19 -PETTC or POEGMA 19 -b-PSt 16 -PETTC as the macro-RAFT agent, and styrene (St) as the monomer to perform TE-PISA or SE-PISA, and testing was performed, and the specific test results are shown in Table 1, wherein the test contents include: monomer conversion, number average molecular weight (M n ) and molecular weight distribution (M w / M n ) of the obtained polymer, particle size, particle size distribution and morphology of the obtained nanoparticles.

[0072] Table 1

[0073]

[0074] Notes: a The number in the subscript of PSt represents the target polymerization degree of PSt; b The monomer conversion was obtained by 1 H NMR; c The number average molecular weight (M n) and molecular weight distribution (M w / M n ) were obtained by GPC; d The particle size and particle size distribution of the obtained nanoparticles were obtained by DLS; e The morphology of the obtained nanoparticles was obtained by TEM, where "-" indicates that the nanoparticles are relatively disordered and cannot be distinguished.

[0075] Example 3

[0076] Synthesis of two-block polymer RAFT agent: POEGMA 19 -PETTC (2.38 g, 0.25 mmol), 2-(diisopropylamino)ethyl methacrylate (DIPEMA) (1.71 g, 8 mmol) and AIBN (3 mg, 0.02 mmol) were dissolved in 5 mL of N,N-dimethylformamide (DMF) and added to a 10 mL polymerization bottle. After three freeze-vacuum-thaw cycles, the polymerization tube was sealed and stirred at 70°C in an oil bath for 4.5 h. The obtained crude product was dialyzed in ethanol to remove unreacted monomers and then vacuum dried to obtain a yellow solid product. The molecular weight and molecular weight distribution (M 1 H NMR chart, as shown in Figure A in Figure 8 , it was calculated that the polymerization degree of poly-2-(diisopropylamino)ethyl methacrylate (PDIPEMA) was 29, marked as POEGMA 19 -b-PDIPEMA 29 -PETTC; POEGMA 19 -b-PDIPEMA 29 The GPC chart of -PETTC is shown in Figure B in Figure 8 .

[0077] Seed emulsion polymerization induced self-assembly (SE-PISA) polymerization kinetics tracking: POEGMA 19 -b-PDIPEMA 29 -PETTC was used as a macromolecular chain transfer agent (also a micellar seed) to control the SE-PISA of DIPEMA monomers in aqueous solution, and the solid content of the reaction system was 20 wt%, and the target polymerization degree DP PDIPEMA =280 of PDIPEMA (POEGMA 19 -b-PDIPEMA 280 ) was as follows.

[0078] Specific preparation method: POEGMA 19 -b-PDIPEMA 29 -PETTC (780 mg, 5 × 10 -2mmol), DIPEMA (2680 mg, 12.6 mmol), azobiscyanopentanoic acid (ACVA, 2.8 mg, 10 -2 mmol), water (13.8 g) and a magnetic stir bar into a polymerization tube. After three freeze- vacuum-thaw cycles, the polymerization tube was sealed. The polymerization tube was then placed in a 70 °C oil bath and the polymerization was allowed to proceed with stirring. At different reaction times, 1 mL of the reaction was removed for monomer conversion and polymer GPC characterization. The results show that the molecular weight of the resulting polymer gradually increases as the monomer conversion increases (as shown in Figure A of Figure 9 , B of Figure A of Figure 9 ). The UV-Vis results show that there is still a very high PETTC end group retention rate after the reaction is completed (as shown in Figure C of Figure 9 ). TEM results show that uniform size distribution of vesicles is obtained (as shown in Figure D of Figure 9 ). The actual picture of the resulting polymer nanomaterial dispersion is shown in Figure E of Figure 9 . After the resulting sample is placed upside down for 1 month, no obvious precipitate is observed at the bottom of the sample tube (as shown in Figure F of Figure 9 ), indicating that no large aggregates are generated during the synthesis. These data show that the SE-PISA strategy causes the macromolecular chain transfer agent to undergo synchronous chain growth, thereby making the emulsion polymerization well controllable, and thus the resulting polymer nanomaterials have good controllability, effectively inhibiting the generation of large aggregates.

[0079] Comparative Example 3

[0080] Comparative Example 3 was performed using the same method as Comparative Example 1 to track the TE-PISA polymerization kinetics, except that POEGMA 19 -PETTC was used as the macromolecular chain transfer agent to regulate the emulsion polymerization induced self-assembly of 2- (diisopropylamino) ethyl methacrylate (DIPEMA) monomer, and the solid content of the reaction system was 20 wt%, and the target polymerization degree DP PDIPEMA of the PDIPEMA was 280 (POEGMA 19 -b-PDIPEMA 280 ). The process was as follows.

[0081] The specific preparation method was as follows: POEGMA 19 -PETTC (475 mg, 5 x 10 -2 mmol), DIPEMA (2980 mg, 14 mmol), azobiscyanopentanoic acid (ACVA, 2.8 mg, 10 -2mmol), water (13.8 g) and a magnetic stir bar were added to a polymerization tube to remove oxygen before polymerization. 1 mL of the reaction was taken out at different reaction time to measure monomer conversion (as shown in Figure A of Figure 10 , and polymer GPC characterization, the results show that the macro-chain transfer agent does not undergo synchronous chain growth (as shown in Figure A and B of Figure 10 ): the nucleated macro-chain transfer agent has a faster chain growth rate due to sufficient contact with monomers, and the macro-chain transfer agent in solution has a slower chain growth rate due to insufficient contact with monomers, and the macro-chain transfer agent gradually nucleates during polymerization, resulting in uncontrollable emulsion polymerization. UV-Vis results show that there is a very high PETTC end group retention rate after the reaction (as shown in Figure C of Figure 10 ). The TEM image of the obtained polymer nanomaterials is shown in Figure D of Figure 10 , and the actual image of the obtained polymer nanomaterial dispersion is shown in Figure E of Figure 10 . The sample was placed upside down after 1 day, and a large amount of precipitate was clearly visible at the bottom of the sample tube (as shown in Figure F of Figure 10 ), indicating that large aggregates were produced during synthesis. These data indicate that the poor controllability of the TE-PISA system is due to the inability of the macro-chain transfer agent to undergo synchronous chain growth, resulting in poor controllability of emulsion polymerization.

[0082] Example 4

[0083] Example 4 was performed using the same method as Example 1, except that POEGMA 19 -b-PDIPEMA 29 -PETTC was used as the macro-chain transfer agent (also the micelle seed) to regulate the seed emulsion polymerization of 2-(diisopropylamino)ethyl methacrylate (DIPEMA) monomer in aqueous phase to induce self-assembly, and the solid content of the reaction system was 20 wt%, and the polymerization degree DP PDIPEMA of PDIPEMA was 160 (POEGMA 19 -b-PDIPEMA 160 ) during the process.

[0084] The specific preparation method is as follows: POEGMA 19 -b-PDIPEMA 29 -PETTC (156 mg, 10 -2 mmol), DIPEMA (279 mg, 1.31 mmol), azobis cyanovaleric acid (ACVA, 0.56 mg, 2 x 10 -3mmol), water (1.74 g) and a magnetic stir bar were added to a polymerization tube and the polymerization reaction was carried out after removing oxygen, and the reaction time was 5 h. The reaction mixture was quickly cooled to room temperature and exposed to air to quench the free radicals to terminate the reaction. Meanwhile, other polymer nanomaterials (POEGMA PDIPEMA (DP PDIPEMA = 80, 120 and 200) were synthesized by using the TE-PISA strategy. 19 -b-PDIPEMA 80 , POEGMA 19 -b-PDIPEMA 120 , POEGMA 19 -b-PDIPEMA 200 . The TEM real image of the obtained polymer nanomaterial is shown in Figure A of Figure 11 ; the real image of the dispersion liquid of the obtained polymer nanomaterial is shown in Figure B of Figure 11 . The obtained sample was inverted after being placed for 1 month, and no obvious precipitate was observed at the bottom of the sample tube (as shown in Figure C of Figure 11 ), indicating that no large aggregates were generated in the synthesis process. Other test data are shown in Table 2.

[0085] Comparative Example 4

[0086] Comparative Example 4 was carried out by using the same method as Comparative Example 1, except that POEGMA 19 -PETTC was used as the macromolecular chain transfer agent to regulate the emulsion polymerization and induce self-assembly of DIPEMA monomers, and the solid content of the reaction system was 20 wt%, and the polymerization process of PDIPEMA with a target polymerization degree DP PDIPEMA = 160 was as follows.

[0087] Specific preparation method: POEGMA 19 -PETTC (95 mg, 10 -2 mmol), DIPEMA (341 mg, 1.6 mmol), azobis cyanovaleric acid (ACVA, 0.56 mg, 2 x 10 -3 mmol), water (1.74 g) and a magnetic stir bar were added to a polymerization tube and the polymerization reaction was carried out after removing oxygen, and the reaction time was 5 h. The reaction mixture was quickly cooled to room temperature and exposed to air to quench the free radicals to terminate the reaction. Meanwhile, other polymer nanomaterials (POEGMA PDIPEMA (DP PDIPEMA = 80, 120 and 200) were synthesized by using the TE-PISA strategy. 19 -b-PDIPEMA 80 , POEGMA 19 -b-PDIPEMA120 , POEGMA 19 -b-PDIPEMA 200 ). The TEM image of the obtained polymer nanomaterials is shown in Figure A of Figure 12 ; the actual image of the obtained polymer nanomaterial dispersion is shown in Figure B of Figure 12 . After the obtained sample was placed upside down for 1 day, a large amount of precipitate was clearly visible at the bottom of the sample tube (as shown in Figure C of Figure 12 ), indicating that large aggregates were generated during the synthesis.

[0088] POEGMA 19 -PETTC or POEGMA 19 -b-PDIPEMA 29 -PETTC as a macro-RAFT agent and DIPEMA as a monomer to perform TE-PISA or SE-PISA, and testing was performed. The specific test results are shown in Table 2 below, wherein the test contents include: monomer conversion, number average molecular weight (M n ) and molecular weight distribution (M w / M n ) of the obtained polymer, and the morphology of the obtained nanoparticles.

[0089] Table 2

[0090]

[0091] Note: a The number in the subscript of PDIPEMA represents the target degree of polymerization of PDIPEMA, and the remaining meanings or test methods are the same as those in Table 1.

[0092] Example 5

[0093] Synthesis of a diblock polymer RAFT agent: POEGMA 19 -PETTC (2.38 g, 0.25 mmol), benzyl methacrylate (BzMA, 1.32 g, 7.5 mmol) and AIBN (3 mg, 0.02 mmol) were dissolved in 5 mL of N,N-dimethylformamide (DMF) and added to a 10 mL polymerization tube. After three cycles of freezing-vacuumizing-thawing, the polymerization tube was sealed and stirred at 70°C in an oil bath for 3 h. The obtained crude product was precipitated in n-hexane three times and vacuum dried to obtain a yellow solid product. The 1 H NMR diagram of the obtained macro-RAFT agent is shown in Figure A of Figure 13 , and it was calculated that the degree of polymerization of the polymethyl benzyl methacrylate (PBzMA) was 21, which is marked as POEGMA 19 -b-PBzMA 21 -PETTC. POEGMA19 -b-PBzMA 21 -PETTC's GPC plot, such as Figure 13 As shown in Figure B.

[0094] SE-PISA was performed using the same method as in Example 1, except that it was performed using POEGMA. 19 -b-PBzMA 21 -PETTC acts as a macromolecular chain transfer agent (and also a micellar seed) to regulate the aqueous seed emulsion polymerization of BzMA monomers to induce self-assembly. The solid content of the reaction system is 20 wt%, and the target degree of polymerization of PBzMA is DP. PBzMA =240 polymer (POEGMA) 19 -b-PBzMA 240 The process is as follows.

[0095] Specific preparation method: POEGMA 19 -b-PBzMA 21 -PETTC (132mg, 10) -2 mmol), BzMA (385 mg, 2.19 mmol), azodicyanovalerate (ACVA, 0.56 mg, 2 × 10⁻⁶ ... -3 mmol), water (2.07 g), and a magnetic stir bar were added to the polymerization tube to remove oxygen, and the polymerization reaction was carried out for 4 h. The reaction mixture was rapidly cooled to room temperature and exposed to air to quench free radicals, thus terminating the reaction. Simultaneously, other DPs were synthesized using the SE-PISA strategy. PBzMA (DP) PBzMA Polymer nanomaterials (POEGMA) with values ​​of 320 and 360) 19 -b-PBzMA 320 POEGMA 19 -b-PBzMA 360 TEM images of the obtained polymer nanomaterials, as shown below. Figure 14 As shown in Figure A; the physical image of the obtained polymer nanomaterial dispersion is shown in Figure A. Figure 14 As shown in Figure B. After the obtained sample was placed for one month and then inverted, no obvious precipitate was observed at the bottom of the sample tube (e.g., ...). Figure 14 As shown in Figure C, this indicates that no large aggregates were generated during the synthesis process. Other test data are shown in Table 3.

[0096] Comparative Example 5

[0097] Comparative Example 5 was performed using the same TE-PISA method as Comparative Example 1, the difference being that it used POEGMA. 19PETTC as a macro-chain transfer agent to regulate the emulsion polymerization of benzyl methacrylate (BzMA) monomer to induce self-assembly, the solid content of the reaction system is 20wt%, the target polymerization degree DP of PBzMA is 240 PBzMA =240 of POEGMA 19 -b-PBzMA 240 is as follows.

[0098] The specific preparation method is: POEGMA 19 -PETTC (95 mg, 10 -2 mmol), BzMA (422 mg, 2.4 mmol), azobis cyanovaleric acid (ACVA, 0.56 mg, 2x10 -3 mmol), water (2.07 g) and a magnetic stirrer are added to a polymerization tube to remove oxygen before polymerization. The reaction time is 4 h. The reaction mixture is quickly cooled to room temperature and exposed to air to quench the free radicals to terminate the reaction. At the same time, other DP PBzMA (DP PBzMA =320 and 360) of polymer nanomaterials (POEGMA 19 -b-PBzMA 320 , POEGMA 19 -b-PBzMA 360 ) are synthesized by using the TE-PISA strategy. The TEM image of the obtained polymer nanomaterial is shown in FIG. A of Figure 15 ; the actual image of the obtained polymer nanomaterial dispersion is shown in FIG. B of Figure 15 . After the sample is placed for 1 day, it is inverted, and a large amount of precipitate can be clearly seen at the bottom of the sample tube (as shown in FIG. C of Figure 15 ), indicating that large aggregates are produced during the synthesis. Other test data are shown in Table 3.

[0099] The above POEGMA 19 -PETTC or POEGMA 19 -b-PBzMA 21 -PETTC is used as a macro-RAFT agent, and benzyl methacrylate (BzMA) is used as a monomer to perform TE-PISA or SE-PISA, and tests are performed. The specific test results are shown in Table 3, wherein the test contents include: monomer conversion, number average molecular weight (M n ) and molecular weight distribution (M w / M n ) of the obtained polymer, and the morphology of the obtained nanoparticles.

[0100] Table 3

[0101]

[0102] Note: a PBzMA subscript number represents the target degree of polymerization of PBzMA, and the rest of the meaning is the same as the test method and Table 1.

[0103] Example 6

[0104] Example 6 adopts the same method as Example 1 for SE-PISA, the difference is that POEGMA 19 -b-PDIPEMA 29 -PETTC as a macromolecular chain transfer agent (also a micellar seed) to regulate St monomer for water phase seed emulsion polymerization induced self-assembly, the solid content of the reaction system is 15wt%, the target degree of polymerization of polystyrene DP PSt =280 polymer (POEGMA 19 -b-PDIPEMA 29 -b-PSt 280 ) is as follows.

[0105] Specific preparation method: POEGMA 19 -b-PDIPEMA 29 -PETTC (156mg, 10 -2 mmol), St (291mg, 2.8mmol), azobiscyanopentanoic acid (ACVA, 0.56mg, 2x10 -3 mmol), water (2.53g) and a magnetic stirrer were added to a polymerization tube. After three cycles of freezing-vacuumizing-thawing, the polymerization tube was sealed for polymerization reaction, and the reaction time was 4h. The reaction mixture was quickly cooled to room temperature and exposed to air to quench the free radicals to terminate the reaction. At the same time, other DP PSt (DP PSt =180 and 330) polymer nanomaterials (POEGMA 19 -b-PDIPEMA 29 -b-PSt 180 , POEGMA 19 -b-PDIPEMA 29 -b-PSt 330 ) were synthesized by SE-PISA strategy. The TEM image of the obtained polymer nanomaterial is shown in Figure A of Figure 16 ; the actual image of the obtained polymer nanomaterial dispersion is shown in Figure B of Figure 16 . The obtained sample was inverted after being placed for 1 month, and no obvious precipitate was observed at the bottom of the sample tube (as shown in Figure 16As shown in Figure C), this indicates that no large aggregates were generated during the synthesis process. These data demonstrate that even though the hydrophobic segments of the micelle seeds and the hydrophobic segments generated by SE-PISA are not the same polymer, the emulsion polymerization and the corresponding polymer nanomaterials in the SE-PISA system still exhibit good controllability.

[0106] With the above POEGMA 19 -b-PDIPEMA 29 -PETTC was used as a macromolecular RAFT reagent (and also as a micelle seed), and styrene (St) was used as the monomer for SE-PISA testing. The specific test results are shown in Table 4. The tests included: monomer conversion rate, and the number-average molecular weight (Mn) of the resulting polymer. n ) and molecular weight distribution (M w / M n ), and the morphology of the obtained nanoparticles.

[0107] Table 4

[0108]

[0109] Example 7

[0110] The macromolecular RAFT reagent PHPMAm-PETTC was synthesized by dissolving N-(2-hydroxypropyl)methacrylamide (HPMAm) (5 g, 35 mmol), PETTC (237 mg, 0.7 mmol), and azodicyanovalerate (ACVA, 39 mg, 0.14 mmol) in a mixed solvent of 5 mL ethanol and 5 mL acidic water (pH ≈ 1) and adding the solution to a 25 mL polymerization flask. After three freeze-vacuum-thaw cycles, the polymerization tube was sealed and the reaction was stirred in an oil bath at 70 °C for 1.5 h. The crude product was precipitated three times in 2-butanone and dried to obtain a yellow solid product. The obtained macromolecular RAFT reagent... 1 H NMR spectrum, as shown Figure 17 As shown in Figure A, its degree of aggregation is calculated to be 27, labeled as PHPMAm. 27 -PETTC. PHPMAm 27 -PETTC's GPC data, such as Figure 17 As shown in Figure B.

[0111] Aqueous phase synthesis of diblock polymer RAFT reagent: PHPMAm 27-PETTC (840 mg, 0.2 mmol), DIPEMA (1.07 g, 5 mmol) and ACVA (6 mg, 0.02 mmol) were added to 5 mL of deionized water, then 1 M aqueous HC1 was added dropwise to adjust the solution to pH ≈ 2. The aqueous solution was added to a 10 mL polymerization tube, after three freeze-thaw-evacuation- thaw cycles, the polymerization tube was sealed and stirred at 70 °C in an oil bath for 3.5 h. About 50 μL of the polymerized solution was taken and added to 0.6 mL of D20 for 1 H NMR characterization (as Figure 18 shown in Figure A of the drawings), the results show that the monomer is almost 100% reacted. 1 M NaOH was added dropwise to the aqueous solution of the resulting product to adjust the pH of the solution to ≈ 7, and the resulting macromolecular RAFT agent was labeled as PHPMAm 27 -b-PDIPEMA 25 -PETTC, the GPC data of which are shown in Figure B of the drawings. Figure 18

[0112] The same method as in Example 1 was used for SE-PISA, except that PHPMAm 27 -b-PDIPEMA 25 -PETTC was used as the macromolecular chain transfer agent (also the micelle seed) to control the St monomer for water-phase seed emulsion polymerization induced self-assembly, the solid content of the reaction system was 15 wt%, and the target polymerization degree of polystyrene (PHPMAm PSt -b-PDIPEMA 27 -b-PSt 25 ) was DP 55 = 55. The preparation process was as follows.

[0113] The specific preparation method was as follows: PHPMAm 27 -b-PDIPEMA 25 -PETTC (190 mg, 2 x 10 -2 mmol), St (114 mg, 1.1 mmol), azobiscyanopentanoic acid (ACVA, 1.12 mg, 4 x 10 -3 mmol), water (1.72 g) and a magnetic stirrer were added to a polymerization tube to remove oxygen before the polymerization reaction, and the reaction time was 3 h. The reaction mixture was quickly cooled to room temperature and exposed to air to quench the free radicals to terminate the reaction. Other DP PSt (DP PSt = 115 and 175) polymer nanomaterials (PHPMAm 27 -b-PDIPEMA 25 -b-PSt 115 , PHPMAm​27 -b-PDIPEMA 25 -b-PSt 175 ). TEM images of the obtained polymer nanomaterials are shown in Figure Figure 19 A; and the real images of the obtained polymer nanomaterial dispersion liquid are shown in Figure Figure 19 B. The obtained sample was inverted after being placed for 1 month, and no obvious precipitate was observed at the bottom of the sample tube (as shown in Figure Figure 19 C), indicating that no large aggregates were generated during the synthesis. Other test data are shown in Table 5.

[0114] Comparative Example 6

[0115] TE-PISA was performed using the same method as in Comparative Example 1: PHPMAm 27 -PETTC was used as a macro-chain transfer agent to regulate the emulsion polymerization of St monomers in water to induce self-assembly, and the solid content of the reaction system was 15 wt%, and the target polymerization degree DP PSt = 80 of polystyrene (PHPMAm 27 -b-PSt 80 ) was prepared as follows.

[0116] The specific preparation method is as follows: PHPMAm 27 -PETTC (168 mg, 4 x 10 -2 mmol), St (333 mg, 3.2 mmol), azobis cyanovaleric acid (ACVA, 2.24 mg, 8 x 10 -3 mmol), water (2.84 g), and a magnetic stirrer were added to a polymerization tube to remove oxygen, and then the polymerization reaction was performed, and the reaction time was 10 h. The reaction mixture was quickly cooled to room temperature and exposed to air to quench the free radicals to terminate the reaction. Other polymers (PHPMAm PSt (DP PSt = 140 and 200) of DP 27 -b-PSt 140 , PHPMAm 27 -b-PSt 200 ) were synthesized using the TE-PISA strategy. TEM images of the obtained polymer nanomaterials are shown in Figure Figure 20 A; and the real images of the obtained polymer nanomaterial dispersion liquid are shown in Figure Figure 20 B; and the obtained sample was inverted after being placed for 1 day, and precipitate was observed at the bottom of the sample tube (as shown in Figure Figure 20 C), indicating that large aggregates were generated during the synthesis. Other test data are shown in Table 5.

[0117] PHPMAm 27 -PETTC or PHPMAm27 -b-PDIPEMA 25 -PETTC was used as a macromolecular RAFT reagent, and styrene (St) was used as the monomer for TE-PISA or SE-PISA. The specific test results are shown in Table 5. The test items included: monomer conversion rate, number-average molecular weight of the resulting polymer (M). n ) and molecular weight distribution (M w / M n The particle size, particle size distribution, and morphology of the obtained nanoparticles were determined.

[0118] Table 5

[0119]

[0120] Note: a The numbers under the PSt subscripts represent the target aggregation degree of PSt, and the rest of the definitions and testing methods are the same as in Table 1.

[0121] Example 8

[0122] The PHPMAm prepared using the SE-PISA strategy in Example 7 27 -b-PDIPEMA 25 -b-PSt 55 The experiment was repeated 5 times under the same conditions, and the TEM images of the obtained nanomaterials are shown below. Figure 21 As shown in Figure A, the DLS data is as follows: Figure 21 Figure B shows that the morphology and size of the nanomaterials obtained from the five repetitions are quite similar, indicating good reproducibility; the physical image of the obtained polymer nanomaterial dispersion is shown in Figure B. Figure 21 As shown in Figure C. After the obtained samples were stored for one month and then inverted, no obvious precipitate was observed at the bottom of the sample tubes (see Figure C). Figure 21 The figure in Figure D shows that the SE-PISA strategy can effectively suppress the formation of large aggregates. Additionally, the PHPMAm obtained from five repeated experiments... 27 -b-PDIPEMA 25 -PSt 55 The GPC curves basically overlap ( Figure 22 This further demonstrates that the SE-PISA strategy has good repeatability.

[0123] Comparative Example 7

[0124] In Comparative Example 6, PHPMAm was prepared using the TE-PISA strategy. 27 -b-PSt 80 The experiment was repeated 5 times under the same conditions, and the TEM images of the obtained nanomaterials are shown below. Figure 23 The A, DLS data are as follows Figure 23The number B in the diagram indicates that the morphology and size of the nanomaterials obtained from the five repetitions fluctuated significantly, demonstrating poor reproducibility. A physical image of the resulting polymer nanomaterial dispersion is shown below. Figure 23 As shown in C; after the obtained samples were left to stand for 1 day, when inverted, obvious precipitate appeared at the bottom of the sample tube (e.g., Figure 23 (As shown in Figure D). PHPMAm obtained from 5 repeated experiments. 27 -b-PSt 80 The GPC curves are also significantly different. Figure 24 This indicates that the repeatability of the TE-PISA strategy is poor.

[0125] Application Example 1

[0126] The PHPMAm prepared repeatedly using SE-PISA in Example 8 27 -b-PDIPEMA 25 -b-PSt 55 Nanomaterials were mixed uniformly with polyvinyl alcohol (PVA) to prepare PVA composite materials.

[0127] The specific steps are as follows: retrieve PHPMAm 27 -b-PDIPEMA 25 -b-PSt 55 160 mg of nanomaterial dispersion (containing 24 mg of nanomaterials) and 8 g of PVA were added to 80 g of water. The mixture was stirred at 95 °C for 2 h (until the PVA was completely dissolved in the water). After cooling, the mixture was spread on a glass plate to dry and prepare a PVA composite film. After drying in a vacuum environment at 40 °C for 8 h, mechanical properties were immediately tested. The tensile strength of the obtained PVA composite material was approximately 55.3-64.5 MPa, and the elongation at break was approximately 311%-348%. Figure 26 ).

[0128] Similarly, PVA films were prepared without nanomaterials according to the above procedure and their mechanical properties were characterized. The tensile strength and elongation at break of the obtained PVA films were 49.9 MPa and 123%, respectively. Figure 25 Compared to the original PVA film, the tensile strength and elongation at break of the PVA composite film were significantly improved, indicating that the nanomaterials obtained by SE-PISA can simultaneously strengthen and toughen composite materials. Furthermore, the mechanical properties of the PVA composite materials obtained from five experiments were relatively similar, demonstrating the good reproducibility of the nanomaterials prepared by SE-PISA, thus ensuring good reproducibility of the properties of the corresponding composite materials.

[0129] Comparative Application Example 1

[0130] The PHPMAm prepared repeatedly using TE-PISA in Comparative Example 7 will be used as a reference. 27 -b-PSt80 Nanomaterials were mixed with PVA to prepare PVA composite materials. The specific operation is as follows.

[0131] Get PHPMAm 27 -b-PSt 80 160 mg of nanomaterial dispersion (containing 24 mg of nanomaterials) and 8 g of PVA were added to 80 g of water. The mixture was stirred at 95 °C for 2 h (until the PVA was completely dissolved in the water). After cooling, the mixture was spread on a glass plate to dry and prepare a PVA composite film. After drying in a vacuum environment at 40 °C for 8 h, mechanical properties were immediately tested. Figure 27 ).

[0132] like Figure 25 , Figure 27 As shown, compared to the original PVA film, the elongation at break of the PVA composite film increased in most cases, but the tensile strength decreased. This is mainly because the nanomaterials obtained by TE-PISA contain large aggregates, which lead to stress defects within the composite material. Furthermore, the mechanical properties of the PVA composite materials obtained from the five experiments varied significantly, indicating that the nanomaterials prepared by TE-PISA have poor reproducibility, resulting in poor reproducibility of the corresponding composite materials.

[0133] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a water-based polymer nanomaterial, comprising: carrying out a living polymerization reaction of a hydrophilic monomer M1 in the presence of a compound A’ to obtain a water-soluble polymer P1-A, wherein P1 is a water-soluble polymer backbone formed by hydrophilic monomer M1 units, and A is a living end formed by the compound A’; carrying out a polymerization reaction of the water-soluble polymer P1-A with a monomer M2 to obtain an amphiphilic block polymer P1-b-P2-A, wherein P2 is a hydrophobic block formed by monomer M2 units; carrying out seed emulsion polymerization induced self-assembly in an aqueous phase with the amphiphilic block polymer P1-b-P2-A as a micellar seed and the addition of a hydrophobic monomer M3 in the presence of an initiator to obtain a water-based polymer nanomaterial; wherein the hydrophilic monomer M1 is selected from any one of a (meth) acrylamide monomer, a (meth) acrylate monomer, and methacrylic acid; the monomer M2 and / or the hydrophobic monomer M3 are each independently selected from any one of a (meth) acrylamide monomer, a (meth) acrylate monomer, and styrene.

2. The method for preparing according to claim 1, wherein: in the case that the living polymerization reaction is an atom transfer radical polymerization reaction, the living end A is a halogen atom.

3. The method for preparing according to claim 1, wherein: in the case that the living polymerization reaction is a reversible addition-fragmentation chain transfer polymerization reaction, the living end A is a chain transfer agent; the chain transfer agent is selected from at least one of a trithioester, a dithioester, a dithiourethane, and a xanthate.

4. The method for preparing according to claim 1, wherein: in the case that the living polymerization reaction is a stable free radical polymerization reaction, the living end A is any one of an alkoxyamine, a triazolinyl group, and an arylazoxyl group.

5. The method for preparing according to claim 1, wherein: the molar ratio of the water-soluble polymer P1-A to the monomer M2 is 1:10-100.

6. The method for preparing according to claim 1, wherein: the hydrophilic monomer M1 includes at least one of N-(2-hydroxypropyl) methacrylamide, polyethylene glycol methacrylate, and methacrylic acid.

7. The method for preparing according to claim 1, wherein: in the case that the monomer M2 is hydrophilic, the monomer M2 and the hydrophobic monomer M3 are different; in the case that the monomer M2 is hydrophobic, the monomer M2 and the hydrophobic monomer M3 are the same or different; wherein the monomer M2 includes at least one of diacetone acrylamide, 2-hydroxypropyl methacrylate, 2-(diisopropylamino)ethyl methacrylate, benzyl methacrylate, glycidyl methacrylate, and styrene; the hydrophobic monomer M3 includes at least one of benzyl methacrylate, 2-(diisopropylamino)ethyl methacrylate, glycidyl methacrylate, and styrene.

8. A water-based polymer nanomaterial prepared by the method for preparing according to any one of claims 1-7.

9. The water-based polymeric nanomaterial of claim 8, wherein, The solid content of the water-based polymer nanomaterial is 5-50 wt%.

10. Use of the water-based polymeric nanomaterial according to claim 8 or 9 for toughening and reinforcing, wherein, The applications include: The water-based polymeric nanomaterials are used as reinforcing agents for toughening and reinforcing elastomers or hydrogels.

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