CN106008795B - A kind of cyclic polymer can self-healing gel synthetic method - Google Patents

Abstract

The invention relates to a synthesis method of a cyclic polymer self-healing gel, comprising the following steps: synthesizing a linear furan random copolymer containing furan by atom transfer radical polymerization; stacking the linear furan random copolymer Nitriding reaction to obtain azide group-containing linear furan random copolymer; cyclization reaction of azide-containing linear furan random copolymer to obtain cyclic furan random copolymer; cyclic furan random copolymerization Bismaleimide and bismaleimide were synthesized into dienes to obtain ring-shaped self-healing gels. The synthesis method of a cyclic self-healing gel described in the present invention has mild reaction conditions, fast reaction rate, high selectivity, high yield and simple post-treatment, and is suitable for industrial production; and is based on cyclic polymers and The reaction between furan and maleimide groups synthesized a ring-shaped self-healing gel, which has good self-healing performance and has a good application prospect.

Description

A Synthetic Method of Cyclic Polymer Self-healing Gel

technical field

The invention relates to the technical field of polymer synthesis, in particular to a method for synthesizing a ring-shaped self-healing gel.

Background technique

It is well known that changes in topology have a greater impact on polymer properties. Cyclic polymers have no end groups and have higher glass transition temperatures, larger diffusion coefficients, smaller hydrodynamic radii, and stronger fluorescence properties due to their special topological structures.

In addition, self-healing gels have always been a hot topic of research by scientists. Since the self-healing gel material can achieve self-repair under certain conditions, it provides a new method for improving the service life of the material, saving resources and protecting the environment.

Currently, the synthesis of self-healing gel materials is mostly based on linear polymers, while there are few reports on self-healing gels based on cyclic polymers. The main reason is that the synthesis process of cyclic polymers is more complicated and difficult, especially in the process of synthesizing functional cyclic polymers, often accompanied by more side reactions.

So far, the combination of atom transfer radical polymerization (ATRP) and copper-catalyzed azide-alkyne cycloaddition (CuAAc) ring closure is an important method for the synthesis of cyclic polymers. This method is widely used due to its high efficiency and simple operation. The Diels-Alder reaction of furan and maleimide is widely used in the synthesis of self-healing gels due to its reversibility.

In view of the above-mentioned defects, the designers actively researched and innovated in order to create a synthesis method of a cyclic polymer self-healing gel, making it more valuable in industry.

Contents of the invention

In order to solve the above-mentioned technical problems, the object of the present invention is to provide a synthesis method of cyclic polymer self-healing gel, which has simple process and high synthesis efficiency.

The synthesis method of the cyclic polymer self-healing gel of the present invention comprises the following steps:

(1) Dissolve furane derivatives, acrylate comonomers, initiators, catalysts, and first ligands in the first organic solvent, and perform atom transfer radical polymerization (ATRP) reaction at 40°C to 80°C Obtain linear furan random copolymer;

(2) Add the linear furan random copolymer, sodium azide, and phase transfer catalyst obtained in step (1) into the container, and add the second organic solvent and water to dissolve, and carry out the azide reaction at 20-50°C. The reaction obtains the linear furan random copolymer containing azide group;

(3) The linear furan random copolymer containing azide group obtained in step (2) is dissolved in the third organic solvent to obtain the first solution, and the catalyst, the second ligand and the third organic solvent are formulated into the second solution, the first solution is added dropwise to the second solution, and a cyclization reaction occurs at 60°C to 100°C to obtain a cyclic furan random copolymer;

(4) The cyclic furan random copolymer and bismaleimide obtained in step (3) are dissolved in the fourth organic solvent, and the diene synthesis reaction (Diels-Alder reaction) is carried out at 30-80° C. ), a self-healing gel of cyclic polymer was obtained.

Further, in step (1), the furane derivatives are furfuryl acrylate (FA) or furfuryl methacrylate (FMA), the specific structural formula of furfuryl acrylate (FA) and furfuryl methacrylate (FMA) as follows:

Further, in step (1), the acrylate comonomer is one or more of methyl methacrylate, butyl methacrylate, methyl acrylate and butyl acrylate.

Further, in step (1), the first ligand is pentamethyldiethylenetriamine, hexamethyltriethylenetetramine, diethylenetriamine, N, N, N', N'-tetrakis(2 -pyridylmethyl)ethylenediamine, tris(2-pyridylmethyl)amine, tris(2-aminoethyl)amine, 1,10-phenanthroline, 1,4,8,11-tetramethyl- One or more of 1,4,8,11-tetraazacyclotetradecane and 2,2'-bipyridine.

Further, in step (1), the initiator is propargyl 2-bromoisobutyrate (PBMP) or butylynyl 2-bromoisobutyrate (BBMP), and the specific structural formulas of PBMP and BBMP are as follows:

Further, the catalyst is one or more of cuprous chloride, cuprous bromide and cuprous iodide.

Further, in step (1), the first organic solvent is one of toluene, anisole, benzene, p-xylene, o-xylene, dimethylsulfoxide or N,N-dimethylformamide.

Further, in step (1), in molar ratio, furane derivatives: acrylate comonomer: initiator: catalyst: first ligand=100:50～400:0.5～2:0.25～2 : 0.25～2, the volume ratio of furane derivatives to the first organic solvent is 50～300:100.

Further, in step (2), in molar ratio, linear random copolymer: sodium azide: phase transfer catalyst=10:10～100:1～10, the volume ratio of the second organic solvent to water is 5 ~20:10.

Further, in step (2), the phase transfer catalyst is tetrabutylammonium bisulfate, tetrabutylammonium bromide, trimethylbenzyl ammonium chloride, trioctylmethylammonium chloride, hexadecyl One or more of trimethylammonium bromide and triethylbenzylammonium chloride.

Further, in step (2), the second organic solvent is one of dichloromethane, chloroform, carbon tetrachloride, ethyl acetate, toluene or anisole.

Further, in step (3), the catalyst is one or more of cuprous chloride, cuprous bromide and cuprous iodide.

Further, in step (3), the second ligand is pentamethyldiethylenetriamine, hexamethyltriethylenetetramine, diethylenetriamine, N, N, N', N'-tetrakis(2 -pyridylmethyl)ethylenediamine, tris(2-pyridylmethyl)amine, tris(2-aminoethyl)amine, 1,10-phenanthroline, 1,4,8,11-tetramethyl- One or more of 1,4,8,11-tetraazacyclotetradecane and 2,2'-bipyridine.

Further, in step (3), the third organic solvent is one of toluene, dimethylsulfoxide, N,N-dimethylformamide, dichloromethane, chloroform or benzene.

Further, in step (3), the linear furan random copolymer containing azide group:catalyst:second ligand=1:25～100:25～200 in molar ratio.

Further, in step (3), the concentration of the azide group-containing linear furan random copolymer is 10 ^-3 ~ 10 ^{- 2} g/mL, and the dropping rate is 0.1 ~ 1 mL/min.

Further, in step (4), the bismaleimide is diphenylmethane bismaleimide (BMI) or 1,12-bis(maleimide) dodecane (12CBMI) , the specific structural formula is as follows:

Further, in step (4), the fourth organic solvent is one of toluene, dichlorobenzene, tetrahydrofuran, anisole or benzene.

Further, in step (4), the organic solvent is volatilized at 80°C to 100°C.

Further, in step (4), the organic solvent can be volatilized in molds of different shapes, so that the cyclic polymer can be polymerized into different shapes by self-healing gel.

Further, in step (4), the molar ratio of the furan group in the cyclic furan random copolymer to the bismaleimide is 10:1˜10:5.

The synthesis route of the cyclic polymer in one of the specific embodiments of the present invention is as follows:

By means of the above scheme, the present invention has the following advantages:

The synthesis method of the cyclic self-healing gel provided by the present invention successfully synthesizes a cyclic polymer containing functional furan groups, which has the advantages of mild reaction conditions, fast reaction rate, high selectivity, high yield and simple post-treatment and other advantages, and is suitable for industrial production; the synthetic method of the present invention synthesizes a ring-shaped self-healing gel based on the Diels-Alder reaction of cyclic polymers and furan and maleimide, which has good self-healing performance and good application prospects.

The above description is only an overview of the technical solution of the present invention. In order to understand the technical means of the present invention more clearly and implement it according to the contents of the description, the following is a detailed description of the preferred embodiments of the present invention with accompanying drawings.

Description of drawings

Fig. 1 is that the present invention adopts the SEC outflow curve figure of the linear furan random copolymer that ATRP polymerization method obtains;

Fig. 2 is that the present invention adopts the nuclear magnetic hydrogen spectrogram of the linear furan random copolymer that the method for ATRP polymerization obtains;

Fig. 3 is the SEC efflux curve figure of linear furan random copolymer and the linear furan random copolymer containing azide group;

Fig. 4 is the infrared spectrogram of linear furan random copolymer and the linear furan random copolymer containing azide group;

Fig. 5 is the SEC efflux curve figure of the linear furan random copolymer containing azide group and the cyclic furan random copolymer;

Fig. 6 is the infrared spectrogram of the linear furan random copolymer containing azide group and the cyclic furan random copolymer;

Fig. 7 is the NMR spectrum of the linear furan random copolymer and the cyclic furan random copolymer containing azide groups.

detailed description

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

Example 1

Add cuprous bromide 0.0980g (0.69mmol), 0.1420g initiator PBMP (0.69mmol), comonomer butyl acrylate 5mL (34.7mmol), 5.2770g furfuryl acrylate (34.7mmol) in the Sulenk bottle successively And 0.1600g of the first ligand hexamethyltriethylenetetramine (0.69mmol), then add 10mL of toluene, after three standard freezing-pumping-thawing cycle operations, tighten the bottle stopper. Then place the Sulenk bottle in an oil bath at 70°C, stir for 24 hours, ATRP reaction occurs, take the tube, use petroleum ether as a precipitant for precipitation, pour the upper solvent after standing, add dichloromethane to dissolve the remaining solid, Wash three times with an aqueous solution of ethylenediaminetetraacetic acid disodium salt to remove the copper salt, dry, concentrate, then precipitate with petroleum ether, pour the upper layer solution, and dry to obtain a light yellow linear furan random copolymer. Figure 1 and Figure 2 are the SEC elution curve and NMR spectrum of the linear furan random copolymer obtained by ATRP polymerization. It can be seen from Figure 1 that the linear furan random copolymer with normal peak shape was successfully obtained. For the copolymer, the number of furan units in the linear furan random copolymer is calculated to be 12 by further calculating the integral value of the characteristic peaks in the NMR spectrum in Fig. 2 .

Add 0.2g linear furan random copolymer (0.038mmol), NaN ₃ 0.025g (0.38mmol) and 0.0129g tetrabutylammonium bisulfate (0.038mmol) to the round bottom flask successively, and add an equal volume of dichloromethane Dissolve the reactants completely with water, and stir the reaction at 20°C for 24h. The reaction solution was separated, the dichloromethane layer was collected, washed three times with water, dried with anhydrous sodium sulfate, suction filtered, rotary evaporated, precipitated, and dried to obtain a linear furan random copolymer containing azide groups. Figure 3 and Figure 4 are the SEC elution curves and infrared spectrograms before and after the azidation of the linear furan random copolymer. The SEC elution curve of the copolymer hardly changed, indicating that no side reactions occurred during the azidation reaction; and a characteristic peak appeared at ²¹⁰⁹ cm in the infrared spectrum of Figure 4, indicating that the linear furan containing azide groups was successfully obtained random copolymer.

Add 800mL of toluene to a 1000mL three-necked flask, place the reaction flask in an oil bath at 70°C, and stir for 2 hours with argon, then add 0.143g of catalyst CuBr (1mmol) and the second ligand pentamethyl to the reaction flask Diethylenetriamine 0.306mL (1.5mmol), stirred under the protection of argon for 5h. Dissolve 0.1 g (0.02 mmol) of azide-containing linear furan random copolymer in 20 mL of toluene, suck it into a 20 mL syringe, and inject it into a three-necked flask with a micro-injection pump at a rate of 0.6 mL/h. After the injection, Reaction for 24h. After the reaction solution was rotary evaporated to remove toluene, a small amount of dichloromethane was added to dissolve it, washed three times with disodium ethylenediaminetetraacetic acid brine to remove copper salt, dried over anhydrous sodium sulfate, suction filtered, rotary evaporated, precipitated, and vacuum dried to constant weight A cyclic furan random copolymer was obtained. Figures 5 to 7 are the SEC elution curves, infrared spectra and H NMR spectra of the linear furan random copolymer containing azide groups before and after the cyclization reaction. It can be seen that after the ring-forming reaction occurs: the SEC efflux curve in Figure 5 moves backward as a whole, the absorption peak of the azide group at ²¹⁰⁹ cm on the infrared spectrum of Figure 6 disappears, and the alkynyl hydrogen on the NMR spectrum of Figure 7 The complete disappearance of the signal shows that the cyclic furan random copolymer has been successfully obtained with high purity.

Dissolve 0.1g (0.019mmol) of cyclic furan random copolymer and 0.037g (0.1mmol) of 12CBMI in 1mL of toluene at 80°C, inject it into the mold while it is hot, evaporate the toluene to dryness at 100°C, and return to 30 After reacting at ℃ for 24 hours, a yellow cyclic polymer self-healing gel was obtained.

Take a whole piece of gel, cut a cross on the gel with a knife, clamp the gel with two pieces of quartz glass, put it in a high-temperature oven at 130°C for 24 hours, and then react in an oven at 50°C for 12 hours. It can be found that the cross cut of the gel disappears, and it returns to the original appearance without wounds. It shows that the obtained cyclic polymer gel has self-healing properties.

Example 2

Add cuprous chloride (0.1725mmol), 0.0379g initiator BBMP (0.1725mmol), comonomer butyl methacrylate 5mL (34.7mmol), 5.7975g furfuryl methacrylate (34.7 mmol) and the first ligand tris(2-pyridylmethyl)amine (0.1725mmol), then add anisole 30mL, after three standard freezing-pumping-thawing cycle operations, tighten the bottle stopper. Then put the Sulenk bottle in an oil bath at 40°C, stir for 24 hours, ATRP reaction occurs, take the tube, use petroleum ether as a precipitant for precipitation, pour the upper solvent after standing, add dichloromethane to dissolve the remaining solid, Wash three times with an aqueous solution of ethylenediaminetetraacetic acid disodium salt to remove the copper salt, dry, concentrate, then precipitate with petroleum ether, pour the upper layer solution, and dry to obtain a light yellow linear furan random copolymer.

Add 0.2g linear furan random copolymer (0.038mmol), NaN ₃ 2.5g (38mmol) and 0.0129g tetrabutylammonium bisulfate (0.038mmol) to the round bottom flask successively, and add 10mL of chloroform and 40mL The reactants were completely dissolved in water, and the reaction was stirred at 50°C for 24h. The reaction solution was separated, the chloroform layer was collected, washed three times with water, dried with anhydrous sodium sulfate, suction filtered, rotary evaporated, precipitated and dried to obtain a linear furan random copolymer containing azide groups.

Add 800mL dimethyl sulfoxide to a 1000mL three-neck flask, place the reaction flask in an oil bath at 100°C, and stir for 2 hours with argon, then add 0.286g of catalyst CuBr (2mmol) and the second ligand to the reaction flask Diethylenetriamine 8.16mL (40mmol), stirred for 5h under the protection of argon. Dissolve 0.1 g (0.02 mmol) of azide group-containing linear furan random copolymer in 10 mL of dimethyl sulfoxide, suck it into a 10 mL syringe, and inject it into a three-necked flask with a micro-syringe pump at a rate of 0.1 mL/h , After the injection, react for 24 hours. After the reaction solution was rotary evaporated to remove dimethyl sulfoxide, a small amount of dichloromethane was added to dissolve it, washed three times with ethylenediaminetetraacetic acid disodium brine to remove copper salt, dried over anhydrous sodium sulfate, suction filtered, rotary evaporated, precipitated, and vacuum dried To constant weight to obtain cyclic furan random copolymer.

Dissolve 0.1g (0.019mmol) of cyclic furan random copolymer and 0.037g (0.1mmol) of BMI in 1mL tetrahydrofuran at 80°C, inject it into the mold while it is hot, evaporate the tetrahydrofuran to dryness at 100°C, and return to 80°C. After reacting at ℃ for 18 hours, a yellow cyclic polymer self-healing gel was obtained.

The invention successfully synthesizes a cyclic polymer containing a functional furan group, and prepares a cyclic polymer self-healing gel based on the Diels-Alder reaction of a furan group and a maleimide group.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention. It should be pointed out that for those of ordinary skill in the art, some improvements can be made without departing from the technical principle of the present invention. and modifications, these improvements and modifications should also be considered as the protection scope of the present invention.

Claims (10)

1. a synthetic method of cyclic polymer self-healing gel, is characterized in that, comprises the following steps: (1) Furanene derivatives, acrylate comonomers, initiators, catalysts, and the first ligand are dissolved in the first organic solvent, and the polymerization reaction is carried out at 40°C to 80°C to obtain a linear furan random copolymer ; The initiator is propargyl 2-bromoisobutyrate or butylynyl 2-bromoisobutyrate; (2) Add the linear furan random copolymer, sodium azide, and phase transfer catalyst obtained in step (1) into a container, and add a second organic solvent and water to dissolve, and carry out at 20-50°C Azidation reaction, obtain the linear furan random copolymer containing azide group; (3) The linear furan random copolymer containing azide group obtained in step (2) is dissolved in the third organic solvent to obtain the first solution, and the catalyst, the second ligand and the third organic solvent are prepared into the second solution, the first solution is added dropwise to the second solution, and a cyclization reaction occurs at 60°C to 100°C to obtain a cyclic furan random copolymer; (4) Dissolve the cyclic furan random copolymer and bismaleimide obtained in step (3) in the fourth organic solvent, and after the organic solvent volatilizes, carry out a diene synthesis reaction at 30-80°C to obtain the described Cyclic polymers make self-healing gels. 2. the synthetic method of cyclic polymer self-healing gel according to claim 1 is characterized in that: in step (1), described furane derivatives are furfuryl acrylate or furfuryl methacrylate ester, the acrylate comonomer is one or more of methyl methacrylate, butyl methacrylate, methyl acrylate and butyl acrylate, and the first ligand is selected from the group consisting of pentamethyl di Ethylenetriamine, Hexamethyltriethylenetetramine, Diethylenetriamine, N,N,N',N'-Tetrakis(2-pyridylmethyl)ethylenediamine, Tris(2-pyridylmethyl)amine , tris(2-aminoethyl)amine, 1,10-phenanthroline, 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane and 2,2 One or more of '-bipyridines. 3. the synthetic method of cyclic polymer self-healing gel according to claim 1 is characterized in that: in step (1), described catalyst is cuprous chloride, cuprous bromide and iodide One or more of cuprous. 4. the synthetic method of cyclic polymer self-healing gel according to claim 1, is characterized in that: in step (1), in molar ratio, described furane derivatives: acrylates copolymerization Monomer: initiator: catalyst: first ligand=100:50～400:0.5～2:0.25～2:0.25～2. 5. the synthetic method of cyclic polymer self-healing gel according to claim 1, is characterized in that: in step (2), by molar ratio, described linear random copolymer: sodium azide : phase transfer catalyst=10:10～100:1～10. 6. the synthetic method of the cyclic polymer self-healing gel according to claim 1 or 5 is characterized in that: in step (2), the phase transfer catalyst is tetrabutylammonium bisulfate, tetrabutylammonium One or more of butyl ammonium bromide, trimethyl benzyl ammonium chloride, trioctyl methyl ammonium chloride, hexadecyl trimethyl ammonium bromide and triethyl benzyl ammonium chloride . 7. the synthetic method of cyclic polymer self-healing gel according to claim 1 is characterized in that: in step (3), described catalyst is cuprous chloride, cuprous bromide and iodide One or more of cuprous, the second ligand is selected from pentamethyldiethylenetriamine, hexamethyltriethylenetetramine, diethylenetriamine, N, N, N', N'- Tetrakis(2-pyridylmethyl)ethylenediamine, tris(2-pyridylmethyl)amine, tris(2-aminoethyl)amine, 1,10-phenanthroline, 1,4,8,11-tetra One or more of methyl-1,4,8,11-tetraazacyclotetradecane and 2,2'-bipyridine. 8. the synthetic method of cyclic polymer self-healing gel according to claim 1 is characterized in that: in step (3), by molar ratio, the linear furan random copolymer containing azide group : catalyst: second ligand = 1:25～100:25～200. 9. the synthetic method of cyclic polymer self-healing gel according to claim 1 is characterized in that: in step (4), described bismaleimide is diphenylmethane bismaleimide imine or 1,12-bis(maleimido)dodecane. 10. the synthetic method of cyclic polymer self-healing gel according to claim 1 is characterized in that: in step (4), the furan group in the cyclic furan random copolymer and the The molar ratio of the bismaleimide is 10:1˜10:5.