Synthesis method of cationic hyperbranched polymer with controllable branching degree

Abstract

The invention discloses a synthesis method of a cationic hyperbranched polymer with a controllable branching degree, and belongs to the field of high polymer materials. The method comprises the following steps: firstly, synthesizing an azide-dialkynyl AB2 monomer with controllable cation density, and then synthesizing the cationic hyperbranched polymer through azide-alkyne click reaction catalyzed by copper. The influence on charge repulsive force in the polymerization process is controlled by regulating and controlling the spacing of cations in the monomer, so that the branching degree of the polymer is regulated and controlled. The synthesis method provided by the invention is mild in reaction condition and high in yield, can design and control the molecular weight and branching degree of the synthesized cationic hyperbranched polymer, and has potential and wide application value in the fields of biological medicines, functional materials and the like.

Description

Technical Field

[0001] The invention belongs to the field of polymer material synthesis, and particularly relates to a method for synthesizing a cationic hyperbranched polymer with controllable branching degree. Background Art

[0002] Hyperbranched polymers are three-dimensional macromolecules with highly branched structures. They have abundant terminal functional groups and are easy to modify, which is conducive to the synthesis of various functional materials. At the same time, their highly branched molecular structure brings them a variety of unique functions. The introduction of cations into the structure of hyperbranched polymers can bring them unique properties such as hydrophilicity. At the same time, they have the advantages of being easier to compress and coat DNA, and lower toxicity than linear or dendritic cationic polymers with regular structures, which makes them have obvious advantages in the fields of targeted drug delivery and cell transfection. Therefore, the topologically controllable synthesis of hyperbranched polymers has great application value.

[0003] However, the current common hyperbranched polymer synthesis scheme is generally difficult to accurately control the degree of branching of the polymer without significantly changing the functionality and main chain structure of the polymer. In general, to control the degree of branching by means of structural design, it is necessary to introduce additional groups or side chain molecular chains in the monomer, and adjust the reactivity or steric hindrance of the monomer to achieve control of the degree of branching. For example, it is reported in the literature (10.1039 / c5py00307e) that the polymerization activity is controlled by adjusting the electronegativity of the reactive group, thereby achieving control of the degree of branching, but at the same time, the molecular weight and polydispersity of the polymer are greatly changed, and the chemical activity of the terminal group is changed, making it difficult to achieve independent design of the parameter of the degree of branching. Therefore, a series of homologue monomers and synthesis methods are designed to achieve independent control of the degree of branching without significantly affecting other structural parameters and properties of the polymer, so that it can be more widely used in some scenes where the degree of branching needs to be accurately designed, which has strong scientific significance and application potential. Summary of the invention

[0004] In view of the problems in the prior art, the present invention provides a method for synthesizing a cationic hyperbranched polymer with controllable branching degree. Under the premise of maintaining the molecular weight, end group reactivity and other properties of the hyperbranched polymer obtained by the reaction basically unchanged, the branching degree of the polymer is independently designed and controlled. By adopting this method, the branching degree of the polymer can be independently and accurately controlled, which is beneficial to the application of biological drug delivery, gene transfection and the like.

[0005] To achieve the purpose of the present invention, the following technical scheme is adopted: a method for synthesizing a cationic hyperbranched polymer with controllable branching degree, comprising the following steps: (1) .

[0006] 1-bromo-2-bromomethyl-3-hydroxypropane is dissolved in an organic solvent, an excess amine compound is added, the reaction is stirred for 4-12 hours, and the excess amine compound and the solvent are removed by rotary evaporation to obtain an intermediate 1. The concentration of the 1-bromo-2-bromomethyl-3-hydroxypropane is 0.05-0.5 mol / L, and the concentration of the amine compound is 0.1-1.5 mol / L and is not less than 2 times the concentration of 1-bromo-2-bromomethyl-3-hydroxypropane.

[0007] (2) .

[0008] The intermediate 1 obtained in step (1) is dissolved in a strong polar solvent, an excess of bromopropyne is added, the mixture is stirred for reaction for 4-12 hours, and the intermediate 2 is precipitated in a precipitant. The concentration of the intermediate 1 is 0.05-0.5 mol / L, and the concentration of the bromopropyne is 0.1-1.5 mol / L and is not less than 2 times the concentration of the intermediate 1. (3) .

[0010] The intermediate 2 obtained in step (2) is dissolved in a strong polar solvent, an excess of an azide-amine compound is added, a copper catalyst is added under the protection of an inert gas, the reaction is stirred for 4 to 12 hours, and the intermediate 3 is precipitated in a precipitant. The concentration of the intermediate 2 is 0.05-0.5 mol / L, the concentration of the azide-amine compound is 0.1-1.5 mol / L and not less than 2 times the concentration of the intermediate 2, and the amount of the copper catalyst is 0.1-5 mg / ml. (4) .

[0012] The intermediate 3 obtained in step (3) is dissolved in a strong polar solvent, an excess of bromopropyne is added, the mixture is stirred for 4-12 hours, and the intermediate 4 is precipitated in a precipitant. The concentration of the intermediate 3 is 0.05-0.5 mol / L, and the concentration of the bromopropyne is 0.1-1.5 mol / L and is not less than twice the concentration of the intermediate 3. (5)

[0014] The intermediate 4 obtained in step (4) is dissolved in an organic solvent, an excess of thionyl chloride is added, and the reaction is stirred for 4-12 hours. After the excess thionyl chloride is removed by rotary evaporation, the residue is dissolved in water, an excess of sodium azide is added, and the temperature is raised to 80-95° C. and the reaction is stirred for 12-72 hours. The product is precipitated in a precipitant, and the precipitate is dissolved in a strong polar solvent and filtered. The filtrate is precipitated with a precipitant to obtain a dialkynyl-azide monomer containing a cation. The concentration of the intermediate 4 is 0.05-0.5 mol / L, the concentration of the thionyl chloride is not more than 1.5 mol / L and not less than 2 times the concentration of the intermediate 4, and the concentration of the sodium azide is not more than 1.5 mol / L and not less than 2 times the concentration of the intermediate 4.

[0015] (6) Dissolving the cationic di-alkynyl-azide monomer obtained in step (5) in a strong polar solvent, adding a copper catalyst under the protection of an inert gas, stirring the reaction for 1 to 12 hours, and precipitating in a precipitant to obtain a cationic hyperbranched polymer with a controllable degree of branching. The concentration of the di-alkynyl-azide monomer is 0.05-1 mol / L, and the amount of the copper catalyst is 0.1-5 mg / ml.

[0016] Furthermore, the organic solvent in steps (1) and (5) is a mixture of one or more of tetrahydrofuran, dichloromethane and chloroform.

[0017] Furthermore, the amine compound in step (1) is one of dimethylamine, dimethylamine hydrate and diethylamine.

[0018] Furthermore, the highly polar solvent in steps (2) to (6) is a mixture of one or more of N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone.

[0019] Furthermore, the precipitant in steps (2) to (6) is a mixture of one or more of diethyl ether, ethyl acetate, acetone, and tetrahydrofuran.

[0020] Furthermore, the azide-amine compound in step (3) is one of dimethylazidoethylamine, dimethylazidopropylamine, dimethylazidobutylamine, dimethylazidopentylamine, dimethylazidohexylamine, dimethylazidoheptylamine, dimethylazidooctylamine or a homologue having more methylene groups in the main chain.

[0021] Furthermore, the copper catalyst in steps (3) and (6) is one of cuprous chloride, cuprous bromide and elemental copper.

[0022] Furthermore, the inert gas in step (6) is one or a mixture of nitrogen and argon.

[0023] By selecting azide-amine raw materials containing different numbers of methylene groups during the synthesis of the monomer, the number of methylene groups between two adjacent quaternary ammonium cationic groups in the monomer can be regulated, thereby achieving regulation of the distance and density of monomer cations. During the polymerization process, the charge repulsion between the polymer and the monomer decreases as the cation density decreases, and the reduction in charge repulsion makes it easier for the polymerization reaction to proceed on non-terminal groups, thereby increasing the degree of branching of the polymer. At the same time, the change in the number of methylene groups has little effect on the electronegativity of the terminal group, and the resulting change in steric hindrance is also small, so it has little effect on the polymer molecular weight and the activity of the terminal group, thereby achieving independent design and regulation of the degree of branching.

[0024] The beneficial effects of the present invention are: By fine-tuning the monomer structure, without significantly changing the molecular weight, dispersibility, reactivity of the terminal groups and other properties, the monomer charge density can be adjusted to control the influence of charge repulsion during the polymerization process, thereby achieving individual design and control of the degree of branching of the polymer.

[0025] A controllable number of cationic groups are introduced into the hyperbranched polymer structure, which brings unique properties such as hydrophilicity and strong polarity to the polymer. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the H NMR spectrum of the diacetylene-azide type monomer containing cations in Example 1.

[0027] Figure 2 This is the H-NMR spectrum of the sample with a polymerization time of 1 hour in Example 1. DETAILED DESCRIPTION

[0028] The following examples are used to further illustrate the present invention, and their purpose is to illustrate the present invention and should not be construed as limiting the scope of the present invention. Unless otherwise specified, all parts by weight and weight percentages are used below.

[0029] The raw materials used in the present invention, unless otherwise specified, are conventional commercially available products; the methods used in the present invention, unless otherwise specified, are conventional methods in the art.

[0030] Among them, the hyperbranched polymer was detected by nuclear magnetic hydrogen spectrum. The peak at 3.8-4.4 in the spectrum is the characteristic peak of the alkynyl group, the multiple peaks at 8.5-9.0 are the characteristic peaks of the triazole ring, and the peak at 1.5-2.0 is the sum of the characteristic peaks of some methylene and methine hydrogen in the polymer, which is related to the number of methylene groups in the azide-amine structure. The degree of branching is calculated by the integral value of the above characteristic peaks. The molecular weight is obtained by gel permeation chromatography (GPC).

[0031] The embodiments of the present invention are further described below with reference to a plurality of embodiments.

[0032] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0033] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0034] Example 1 (1) In a 50 ml round-bottom flask, 0.005 mol of 1-bromo-2-bromomethyl-3-hydroxypropane and 25 ml of tetrahydrofuran were added, and 0.015 mol of dimethylamine was added. The mixture was stirred for 4 hours, and the excess dimethylamine and tetrahydrofuran were removed by rotary evaporation to obtain intermediate 1.

[0035] (2) The obtained intermediate 1 was dissolved in 25 ml of N,N-dimethylformamide, and 0.015 mol of bromopropyne was added. The mixture was stirred at room temperature for 4 hours. The system was precipitated in ether and the solid was collected by centrifugation to obtain intermediate 2.

[0036] (3) The intermediate 2 was dissolved in 25 ml of N,N-dimethylformamide, and 0.015 mol of dimethylazidopropylamine was added. 10 mg of cuprous bromide was added under inert gas protection. The mixture was stirred at room temperature for 4 hours, precipitated in ether, and the solid was collected by centrifugation to obtain the intermediate 3.

[0037] (4) The obtained intermediate 3 was dissolved in 25 ml of N,N-dimethylformamide, and 0.015 mol of bromopropyne was added. The mixture was stirred at room temperature for 12 hours, precipitated in ether, and the solid was collected by centrifugation to obtain intermediate 4.

[0038] (5) The obtained intermediate 4 was dissolved in 25 ml of dichloromethane, and 0.01 mol of thionyl chloride was added. The mixture was refluxed and stirred for 4 hours. After the excess thionyl chloride was removed by rotary evaporation, the residue was dissolved in water, 0.01 mol of sodium azide was added, and the temperature was raised to 85° C. and stirred for 72 hours. The product was precipitated in ethanol. The precipitate was dissolved in N,N-dimethylformamide and filtered. The filtrate was precipitated with ethanol to obtain a di-alkynyl-azide monomer containing a cation.

[0039] (6) The obtained cationic diacetyl-azide monomer was dissolved in 25 ml of N,N-dimethylformamide, and 10 mg of cuprous bromide was added under the protection of nitrogen and argon mixed gas. The mixture was stirred at room temperature for 5 hours. Samples were taken at regular intervals, and the product was precipitated in ether to obtain a cationic hyperbranched polymer with controllable branching degree.

[0040] The NMR characterization of the obtained diacetylene-azide monomer containing cations is as follows: Figure 1 The nuclear magnetic hydrogen spectrum of the hyperbranched polymer obtained by reacting step (6) for 1 hour is as follows Figure 2 The molecular weight and branching degree data of the obtained cationic hyperbranched polymer are shown in Table 1.

[0041] Example 2 (1) In a 50 ml round-bottom flask, 0.005 mol of 1-bromo-2-bromomethyl-3-hydroxypropane and 25 ml of chloroform were added, and 0.015 mol of dimethylamine was added. The mixture was stirred for 4 hours, and the excess dimethylamine and tetrahydrofuran were removed by rotary evaporation to obtain intermediate 1.

[0042] (2) The obtained intermediate 1 was dissolved in 25 ml of N,N-dimethylformamide, and 0.015 mol of bromopropyne was added. The mixture was stirred at room temperature for 4 hours. The system was precipitated in ether and the solid was collected by centrifugation to obtain intermediate 2.

[0043] (3) The intermediate 2 was dissolved in 25 ml of dimethyl sulfoxide, and 0.015 mol of dimethylazidehexylamine was added. 10 mg of cuprous bromide was added under inert gas protection. The mixture was stirred at room temperature for 4 hours, precipitated in ether, and the solid was collected by centrifugation to obtain the intermediate 3.

[0044] (4) The obtained intermediate 3 was dissolved in 25 ml of N,N-dimethylformamide, and 0.015 mol of bromopropyne was added. The mixture was stirred at room temperature for 8 hours, precipitated in ethyl acetate, and the solid was collected by centrifugation to obtain intermediate 4.

[0045] (5) The obtained intermediate 4 was dissolved in 25 ml of chloroform, and 0.01 mol of thionyl chloride was added. The mixture was refluxed and stirred for 4 hours. After the excess thionyl chloride was removed by rotary evaporation, the residue was dissolved in water, 0.01 mol of sodium azide was added, and the temperature was raised to 85° C. and stirred for 72 hours. The product was precipitated in ethanol. The precipitate was dissolved in N,N-dimethylformamide and filtered. The filtrate was precipitated with ethanol to obtain a di-alkynyl-azide monomer containing a cation.

[0046] (6) The obtained cationic diacetyl-azide monomer was dissolved in 25 ml of N,N-dimethylformamide, and 10 mg of elemental copper was added under argon protection. The mixture was stirred at room temperature for 10 hours. Samples were taken at regular intervals and the product was precipitated in ether to obtain a cationic hyperbranched polymer with controllable branching degree.

[0047] The molecular weight and branching degree of the obtained hyperbranched polymer are shown in Table 1.

[0048] Example 3 (1) In a 50 ml round-bottom flask, 0.005 mol of 1-bromo-2-bromomethyl-3-hydroxypropane and 25 ml of tetrahydrofuran were added, and 0.015 mol of dimethylamine was added. The mixture was stirred for 4 hours, and the excess dimethylamine and tetrahydrofuran were removed by rotary evaporation to obtain intermediate 1.

[0049] (2) The obtained intermediate 1 was dissolved in 25 ml of N,N-dimethylformamide, and 0.015 mol of bromopropyne was added. The mixture was stirred at room temperature for 4 hours. The system was precipitated in ether and the solid was collected by centrifugation to obtain intermediate 2.

[0050] (3) The intermediate 2 was dissolved in 25 ml of N,N-dimethylformamide, and 0.015 mol of dimethylazidedecylamine was added. Under the protection of inert gas, 10 mg of cuprous bromide was added. The mixture was stirred at room temperature for 4 hours, precipitated in ether, and the solid was collected by centrifugation to obtain the intermediate 3.

[0051] (4) The obtained intermediate 3 was dissolved in 25 ml of N,N-dimethylformamide, and 0.015 mol of bromopropyne was added. The mixture was stirred at room temperature for 4 hours, precipitated in ether, and the solid was collected by centrifugation to obtain intermediate 4.

[0052] (5) The obtained intermediate 4 was dissolved in 25 ml of dichloromethane, and 0.01 mol of thionyl chloride was added. The mixture was refluxed and stirred for 4 hours. After the excess thionyl chloride was removed by rotary evaporation, the residue was dissolved in water, 0.01 mol of sodium azide was added, and the temperature was raised to 85° C. and stirred for 72 hours. The product was precipitated in ether. The precipitate was dissolved in N,N-dimethylformamide and filtered. The filtrate was precipitated with ethanol to obtain a di-alkynyl-azide monomer containing a cation.

[0053] (6) The obtained cationic diacetyl-azide monomer was dissolved in 25 ml of N,N-dimethylformamide, and 10 mg of cuprous chloride was added under nitrogen protection. The mixture was stirred at room temperature for 1 hour. Samples were taken at regular intervals, and the product was precipitated in ether to obtain a cationic hyperbranched polymer with controllable branching degree.

[0054] Table 1. Molecular weight and branching degree data of hyperbranched polymers

[0055] It can be found from Table 1 that by fine-tuning the monomer structure (adding several methylene groups), it is possible to independently design and regulate the degree of branching without significantly changing the polymerization time and number average molecular weight. At the same time, the added methylene group basically does not change the electronegativity of the terminal group, which keeps the reactivity of the terminal group of the product basically unchanged. As the number of methylene groups in the monomer increases, the cationic density of the monomer and polymer decreases, resulting in a decrease in the charge repulsion of the polymer, thereby achieving an increase in the degree of branching.

[0056] Example 4 (1) In a 50 ml round-bottom flask, tetrahydrofuran was used as solvent to prepare 0.05 mol / L 1-bromo-2-bromomethyl-3-hydroxypropane, and dimethylamine hydrate was added to make the concentration of dimethylamine hydrate 0.1 mol / L. The reaction was stirred for 12 hours, and the excess dimethylamine hydrate and tetrahydrofuran were removed by rotary evaporation to obtain intermediate 1.

[0057] (2) The obtained intermediate 1 was dissolved in N,N-dimethylformamide to a concentration of 0.05 mol / L, and propyne bromide was added to a concentration of 0.1 mol / L. The mixture was stirred at room temperature for 12 hours. The system was precipitated in ether and the solid was collected by centrifugation to obtain intermediate 2.

[0058] (3) The obtained intermediate 2 was dissolved in N,N-dimethylformamide to a concentration of 0.05 mol / L, dimethylazidedecylamine was added to a concentration of 0.1 mol / L, and cuprous bromide was added under inert gas protection to a concentration of 0.1 mg / ml. The reaction was stirred at room temperature for 12 hours, precipitated in ether, and the solid was collected by centrifugation to obtain intermediate 3.

[0059] (4) The obtained intermediate 3 was dissolved in N,N-dimethylformamide to a concentration of 0.05 mol / L, and propyne bromide was added to a concentration of 0.1 mol / L. The mixture was stirred at room temperature for 12 hours, precipitated in ether, and the solid was collected by centrifugation to obtain intermediate 4.

[0060] (5) The obtained intermediate 4 was dissolved in dichloromethane to a concentration of 0.05 mol / L, and thionyl chloride was added to a concentration of 0.1 mol / L. The mixture was refluxed and stirred for 4 hours. Excess thionyl chloride was removed by rotary evaporation, and the residue was dissolved in water. Sodium azide was added to a concentration of 0.1 mol / L. The mixture was heated to 95° C. and stirred for 12 hours. The product was precipitated in tetrahydrofuran. The precipitate was dissolved in N,N-dimethylformamide and filtered. The filtrate was precipitated with ethanol to obtain a di-alkynyl-azide monomer containing a cation.

[0061] (6) The obtained cationic diacetyl-azide monomer was dissolved in N,N-dimethylformamide at a concentration of 0.05 mol / L. Cuprous bromide was added under argon protection to a concentration of 0.1 mg / ml. The mixture was stirred at room temperature for 5 hours. The product was precipitated in ether to obtain a cationic hyperbranched polymer with controllable branching degree.

[0062] Example 5 (1) In a 50 ml round-bottom flask, tetrahydrofuran was used as solvent to prepare 0.5 mol / L 1-bromo-2-bromomethyl-3-hydroxypropane, and diethylamine was added to make the diethylamine concentration 1.5 mol / L. The reaction was stirred for 12 hours, and the excess diethylamine and tetrahydrofuran were removed by rotary evaporation to obtain intermediate 1.

[0063] (2) The obtained intermediate 1 was dissolved in N,N-dimethylformamide to a concentration of 0.5 mol / L, and propyne bromide was added to a concentration of 1.5 mol / L. The mixture was stirred at room temperature for 8 hours. The system was precipitated in diethyl ether, and the solid was collected by centrifugation to obtain intermediate 2.

[0064] (3) The intermediate 2 obtained was dissolved in dimethyl sulfoxide to a concentration of 0.5 mol / L, dimethylazidedecylamine was added to a concentration of 1.5 mol / L, and cuprous bromide was added under inert gas protection to a concentration of 5 mg / ml. The reaction was stirred at room temperature for 5 hours, precipitated in ether, and the solid was collected by centrifugation to obtain the intermediate 3.

[0065] (4) The obtained intermediate 3 was dissolved in N-methylpyrrolidone to a concentration of 0.5 mol / L, and propyne bromide was added to a concentration of 1.5 mol / L. The mixture was stirred at room temperature for 6 hours, precipitated in ether, and the solid was collected by centrifugation to obtain intermediate 4.

[0066] (5) The intermediate 4 obtained was dissolved in dichloromethane to a concentration of 0.5 mol / L, and thionyl chloride was added to a concentration of 1.5 mol / L. The mixture was refluxed and stirred for 4 hours. Excess thionyl chloride was removed by rotary evaporation, and the residue was dissolved in water. Sodium azide was added to a concentration of 1.5 mol / L. The mixture was heated to 80° C. and stirred for 72 hours. The product was precipitated in ether. The precipitate was dissolved in N,N-dimethylformamide and filtered. The filtrate was precipitated with ethanol to obtain a di-alkynyl-azide monomer containing a cation.

[0067] (6) The obtained cationic diacetyl-azide monomer was dissolved in N,N-dimethylformamide at a concentration of 1 mol / L. Cuprous bromide was added under nitrogen protection to a concentration of 5 mg / ml. The mixture was stirred at room temperature for 12 hours. The product was precipitated in ether to obtain a cationic hyperbranched polymer with controllable branching degree.

[0068] The above embodiments describe in detail the structure, features and effects of the present invention. The above are only preferred embodiments of the present invention. Any changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments with equivalent changes, which do not exceed the scope covered by the specification, should be within the protection scope of the present invention.

Claims

1. A method for synthesizing a cationic hyperbranched polymer with controllable branching degree, characterized in that: The following steps are involved: (1) dissolving 1-bromo-2-bromomethyl-3-hydroxypropane in an organic solvent, adding an excess amine compound, stirring the reaction for 4-12 hours, and removing the excess amine compound and the solvent by rotary evaporation to obtain an intermediate 1; the concentration of the 1-bromo-2-bromomethyl-3-hydroxypropane is 0.05-0.5 mol / L, and the concentration of the amine compound is 0.1-1.5 mol / L and is not less than 2 times the concentration of 1-bromo-2-bromomethyl-3-hydroxypropane; (2) dissolving the intermediate 1 obtained in step (1) in a strong polar solvent, adding an excess of propyne bromide, stirring the reaction for 4-12 hours, and precipitating in a precipitant to obtain an intermediate 2; the concentration of the intermediate 1 is 0.05-0.5 mol / L, and the concentration of the propyne bromide is 0.1-1.5 mol / L and is not less than 2 times the concentration of the intermediate 1; (3) dissolving the intermediate 2 obtained in step (2) in a strong polar solvent, adding an excess of an azide-amine compound, adding a copper catalyst under inert gas protection, stirring the reaction for 4 to 12 hours, and precipitating in a precipitant to obtain an intermediate 3; the concentration of the intermediate 2 is 0.05-0.5 mol / L, the concentration of the azide-amine compound is 0.1-1.5 mol / L and not less than 2 times the concentration of the intermediate 2, and the amount of the copper catalyst is 0.1-5 mg / ml; (4) dissolving the intermediate 3 obtained in step (3) in a strong polar solvent, adding an excess of propyne bromide, stirring the reaction for 4-12 hours, and precipitating in a precipitant to obtain an intermediate 4; the concentration of the intermediate 3 is 0.05-0.5 mol / L, and the concentration of the propyne bromide is 0.1-1.5 mol / L and is not less than 2 times the concentration of the intermediate 3; (5) dissolving the intermediate 4 obtained in step (4) in an organic solvent, adding an excess of thionyl chloride, stirring and reacting for 4-12 hours, removing the excess thionyl chloride by rotary evaporation, dissolving the residue in water, adding an excess of sodium azide, heating to 80-95° C. and stirring and reacting for 12-72 hours, the product precipitates in a precipitant, the precipitate is dissolved in a strong polar solvent and filtered, and the filtrate is precipitated with a precipitant to obtain a diacetylene-azide monomer containing a cation; the concentration of the intermediate 4 is 0.05-0.5 mol / L, the concentration of the thionyl chloride is not more than 1.5 mol / L and not less than 2 times the concentration of the intermediate 4, and the concentration of the sodium azide is not more than 1.5 mol / L and not less than 2 times the concentration of the intermediate 4; (6) dissolving the cation-containing dialkynyl-azide monomer obtained in step (5) in a strong polar solvent, adding a copper catalyst under the protection of an inert gas, stirring the reaction for 1 to 12 hours, and precipitating in a precipitant to obtain a cationic hyperbranched polymer with a controllable degree of branching; the concentration of the dialkynyl-azide monomer is 0.05-1 mol / L, and the amount of the copper catalyst is 0.1-5 mg / ml.

2. The method according to claim 1, characterized in that The organic solvent is one or more of tetrahydrofuran, dichloromethane and chloroform.

3. The method according to claim 1, characterized in that The amine compound in step (1) is one of dimethylamine, dimethylamine hydrate and diethylamine.

4. The method according to claim 1, characterized in that: The strong polar solvent is one or more of N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone.

5. The method according to claim 1, characterized in that The precipitant is one or more of ether, ethyl acetate, acetone and tetrahydrofuran.

6. The method according to claim 1, characterized in that The azide-amine compound in step (3) is one of dimethylazidoethylamine, dimethylazidopropylamine, dimethylazidobutylamine, dimethylazidopentylamine, dimethylazidohexylamine, dimethylazidoheptylamine, dimethylazidooctylamine or a homologue having more methylene groups in the main chain.

7. The method according to claim 1, characterized in that The copper catalyst in steps (3) and (6) is one of cuprous chloride, cuprous bromide and elemental copper.

8. The method according to claim 1, characterized in that The inert gas in step (6) is one or a mixture of nitrogen and argon.

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