CN116948205A - Polyurethane acrylate elastomer and its preparation method and application - Google Patents

Abstract

The invention discloses a polyurethane acrylate elastomer and its preparation method and application. It utilizes carboxylated multi-walled carbon nanotubes and hydroxypropyl acrylate to perform an esterification reaction to obtain grafted double bond functionally modified multi-walled carbon nanotubes. Tube; Utilize diisocyanate monomer and polyglycol monomer to carry out nucleophilic addition reaction, and then add hydroxyethyl acrylate to introduce double bonds to obtain double bond-terminated polyurethane emulsion; Utilize double bond-terminated polyurethane emulsion, butyl acrylate Multi-walled carbon nanotubes functionalized with esters and grafted double bonds are subjected to reversible addition-fragmentation bond transfer radical polymerization to obtain multi-walled carbon nanotube-modified polyurethane acrylate emulsion; modified to multi-walled carbon nanotubes Coordinated metal ions are introduced into a polyurethane acrylate emulsion and dried to obtain a polyurethane acrylate elastomer; the invention has the characteristics of controllable molecular weight, excellent mechanical strength and toughness and self-healing, and serves as a self-healing and stretchable elastomer. Conductive devices have potential applications.

Description

Polyurethane acrylate elastomer and its preparation method and application

Technical field

The invention belongs to the technical field of polymer material synthesis, and particularly relates to a polyurethane acrylate elastomer and its preparation method and application.

Background technique

As a smart material, self-healing elastomer materials can repair cracks or local damage caused by external forces during use, thereby restoring their original functions and extending their service life; polyurethane acrylate (PUA) contains acrylic acid Functional groups and urethane bonds, the cured polymer has the high wear resistance, adhesion, flexibility, high peel strength and excellent low temperature resistance of polyurethane as well as the excellent optical properties and weather resistance of polyacrylate. A radiation curing material with excellent comprehensive properties, it is widely used in coatings, adhesives, plastics, synthetic fibers, coated fibers and other fields.

At present, metal coordination bonds are usually introduced into the polyurethane acrylate network to form a metal coordination self-healing polyurethane elastomer system; in which, whether at the end of the polymer chain or as a pendant group, hydrogen bonds can be balanced, Thereby adjusting the mechanical properties and self-healing properties of the polymer; however, the main problem with the existing metal coordination self-healing polyurethane elastomer system is that the tensile breaking strength of the elastomer is too low to meet engineering applications; secondly, among them The disulfide bonds can trigger chain exchange reactions under heat, ultraviolet light irradiation and redox conditions. The temperature required for self-healing is too high, limiting practical applications.

Therefore, there is an urgent need to develop a new polyurethane acrylate elastomer that has high mechanical strength and toughness as well as self-healing characteristics.

Contents of the invention

In view of the technical problems existing in the prior art, the present invention provides a polyurethane acrylate elastomer and its preparation method and application to solve the problem that the tensile breaking strength of the existing metal coordination self-healing polyurethane elastomer system is too low. It is not enough to meet engineering applications; secondly, the disulfide bonds in it can trigger chain exchange reactions under heat, ultraviolet light irradiation and redox conditions, and the temperature required for self-repair is too high, which limits technical problems in practical applications.

In order to achieve the above objects, the technical solutions adopted by the present invention are:

The invention provides a method for preparing polyurethane acrylate elastomer, which includes:

Carboxylated multi-walled carbon nanotubes are used to perform an esterification reaction with hydroxypropyl acrylate to obtain multi-walled carbon nanotubes functionalized with grafted double bonds;

Utilize diisocyanate monomer and polyglycol monomer to perform a nucleophilic addition reaction, and then add hydroxyethyl acrylate to introduce double bonds to obtain a double bond-terminated polyurethane emulsion;

Utilizing the double bond-terminated polyurethane emulsion, butyl acrylate and the grafted double bond functionalized modified multi-walled carbon nanotubes, the multi-walled carbon nanotubes modified by reversible addition-fragmentation bond transfer radical polymerization are obtained. Resistant polyurethane acrylate emulsion;

Coordinated metal ions are introduced into the multi-walled carbon nanotube modified polyurethane acrylate emulsion and dried to obtain the polyurethane acrylate elastomer.

Further, the process of using carboxylated multi-walled carbon nanotubes and hydroxypropyl acrylate to perform an esterification reaction to obtain multi-walled carbon nanotubes grafted with double bond functional modification is as follows:

Carboxylated multi-walled carbon nanotubes, hydroxypropyl acrylate, hydroquinone, anhydrous sodium sulfate and methyl isoamyl ketone were ultrasonicated at room temperature under nitrogen protection; then the temperature was raised to the preset temperature, and at the preset temperature Stir at a constant temperature; then add absolute ethanol for dilution, and filter to obtain a filter cake; wash and dry the filter cake to obtain the grafted double bond functionalized multi-walled carbon nanotubes.

Further, the mass ratio of carboxylated multi-walled carbon nanotubes, hydroxypropyl acrylate, hydroquinone, anhydrous sodium sulfate and methyl isoamyl ketone is: (5～8):(20～30):(0.5 ~1):(10~15):(40~50).

Further, a nucleophilic addition reaction is performed between diisocyanate monomer and polyglycol monomer, and then hydroxyethyl acrylate is added to introduce double bonds to obtain a double bond-terminated polyurethane emulsion. The process is as follows:

Mix diisocyanate monomer, polyglycol monomer and organic solvent, add dibutyltin dilaurate for reaction, then add chain extender and cross-linking agent for reaction, and then add organic solvent and hydroxyethyl acrylate to obtain the result The double bond-terminated polyurethane emulsion.

Further, the diisocyanate monomer is one of isophorone diisocyanate, toluene diisocyanate and diphenylmethane diisocyanate; the polyglycol monomer is polycaprolactone diol, poly One of tetrahydrofuran ether glycol and poly(1-butanediol adipate) and 4-butylene glycol ester glycol; the chain extender is dihydroxydiethylthiuram disulfide and bis(2-hydroxyethyl) One of the disulfides; the cross-linking agent is 5,10,15,20-tetrakis (4-hydroxyphenyl) porphyrin and 5,10,15,20-tetrakis (4-aminophenyl) porphyrin A kind of phyrin.

Further, using the double bond-terminated polyurethane emulsion, butyl acrylate and the grafted double bond functionalized modified multi-walled carbon nanotubes, multi-walled carbon nanotubes are obtained through reversible addition-fragmentation bond transfer radical polymerization. The process of nanotube-modified polyurethane acrylate emulsion is as follows:

Mix the double bond-terminated polyurethane emulsion, butyl acrylate, the grafted double bond functionalized multi-walled carbon nanotubes and the organic solvent evenly, then add RAFT chain transfer agent to stir the reaction, keep warm, and cool to room temperature. The material is discharged to obtain multi-walled carbon nanotube modified polyurethane acrylate emulsion.

Further, the process of introducing coordinated metal ions into the multi-walled carbon nanotube modified polyurethane acrylate emulsion and drying to obtain the polyurethane acrylate elastomer is as follows:

After mixing the ethanol solution of metal ions and the multi-walled carbon nanotube modified polyurethane acrylate emulsion, the reaction is continued with stirring to obtain a self-healing elastomer emulsion; the self-healing elastomer emulsion is dried to obtain the polyurethane Acrylic elastomer.

Further, the metal ion is one of iron ion, nickel ion, copper ion, cobalt ion, manganese ion and zinc ion.

The invention also provides a polyurethane acrylate elastomer, which is prepared by using the preparation method of a polyurethane acrylate elastomer;

Among them, the molecular weight of the polyurethane acrylate elastomer is 62820 to 64430; when the film-like polyurethane acrylate elastomer breaks, it can achieve a self-healing efficiency of 85.2% to 86.8% under visible light irradiation for 12 to 24 hours. , can achieve 100% self-healing efficiency under the condition of 0.5-1h irradiation under ultraviolet light; the tensile strength of the polyurethane acrylate elastomer is 46.6-58.6MPa, and the elongation at break is 1263%-1585%.

The invention also provides an application of polyurethane acrylate elastomer as a self-healing stretchable conductive device.

Compared with the prior art, the beneficial effects of the present invention are:

The invention provides a polyurethane acrylate elastomer and its preparation method and application. It utilizes the reversible addition-fragmentation chain transfer radical polymerization (RAFT) method to make the polymer molecular mass distribution more balanced and contribute to output. Reliable and sustained product performance; secondly, the introduction of disulfide bonds (dynamic covalent bonds) into the polymer can be homogenized into sulfur radicals under visible light irradiation, and the chain segments can be regenerated during the process of sulfide radicals regenerating disulfide bonds. Recombination; at the same time, the four nitrogen atoms in the porphyrin macrocycle are used to form an environment with a certain spatial position and coordination ability, forming a stable complex with metal ions. In addition, polyurethane itself has hydrogen bonding to form a strong metal complex. The highly dynamic cross-linked network formed by the combination of site bonds and weak hydrogen bonds greatly improves the self-healing efficiency of polymer elastomers, thereby realizing the repair of polymer cracks; finally, the functionally modified multi-wall Carbon nanotubes are directly copolymerized into polymer molecular chains. Compared with traditional doping or physical blending methods, the form of chemical bonds ensures that the material does not phase separate, has high stability, and greatly improves the mechanical strength of the material. ; The polyurethane acrylate elastomer has the characteristics of simple preparation process, controllable molecular weight, excellent mechanical strength and toughness, and self-healing. The elastomer material is used as a self-healing and stretchable conductive device, and is protected by a coating on the surface. , biomedical materials, flexible wearable electronics, lithium batteries, aerospace and other fields have potential application prospects.

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects solved by the present invention clearer, the following specific examples will further describe the present invention in detail. It should be understood that the specific embodiments described here are only used to explain the present invention and are not intended to limit the present invention.

The invention provides a method for preparing polyurethane acrylate elastomer, which includes: utilizing carboxylated multi-walled carbon nanotubes and hydroxypropyl acrylate to perform an esterification reaction to obtain grafted double bond functionally modified multi-walled carbon nanotubes. ; Utilize diisocyanate monomer and polyglycol monomer to carry out nucleophilic addition reaction, and then add hydroxyethyl acrylate to introduce double bonds to obtain a double bond-terminated polyurethane emulsion; Utilize the double bond-terminated polyurethane emulsion, acrylic acid Butyl ester and the grafted double bond functionalized modified multi-walled carbon nanotubes are subjected to reversible addition-breaking bond transfer radical polymerization to obtain a multi-walled carbon nanotube modified polyurethane acrylate emulsion; to the polyurethane acrylate emulsion is obtained. Coordinated metal ions are introduced into the wall carbon nanotube-modified polyurethane acrylate emulsion and dried to obtain the polyurethane acrylate elastomer.

Specifically, the preparation method includes the following steps:

Step 1. Combine carboxylated multi-walled carbon nanotubes, hydroxypropyl acrylate, hydroquinone, anhydrous sodium sulfate and methyl isoamyl ketone in a mass ratio of (5~8):(20~30):( After mixing at a ratio of 0.5~1):(10~15):(40~50), ultrasonicate at room temperature under nitrogen protection, then heat up to a preset temperature, and perform constant temperature stirring at the preset temperature; then add anhydrous The ethanol is diluted and filtered through a filter membrane to obtain a filter cake; the filter cake is washed with deionized water and dried to obtain multi-walled carbon nanotubes functionalized with grafted double bonds.

In step 1, when ultrasonic at room temperature, the ultrasonic power is 80-100kHz, and the ultrasonic time is 0.5-1.0h; preferably, the preset temperature is 100°C, and the constant temperature stirring time is 24h; when absolute ethanol is added for dilution, the carboxyl group The mass ratio of multi-walled carbon nanotubes to absolute ethanol is (5-8): (100-150); the filter membrane uses polyvinylidene fluoride with a pore size of 0.22 μm; preferably, the number of cleanings is three times; vacuum is used for drying Drying; preferably, the vacuum drying temperature is 50°C and the time is 24 hours.

Step 2: In terms of parts by mass, 17-25 parts of the dried diisocyanate monomer, 21-45 parts of the polyglycol monomer and 25-35 parts of the organic solvent are heated at 80°C under nitrogen protection. Stir and mix evenly; then add 0.1 to 0.5 parts of dibutyltin dilaurate and react for 0.5 to 1 hour; after the reaction, add 1.5 to 2.1 parts of chain extender to react for 0.5 to 1 hour, and then add 0.7 to 1.0 parts of cross-linking agent. React for 0.5 to 1 hour; then, keep the reaction for 2 to 3 hours, cool to 60°C, add 28 to 40 parts of organic solvent, and add 3.6 to 7.5 parts of hydroxyethyl acrylate to obtain a double bond-terminated polyurethane emulsion.

In step 2, the diisocyanate monomer is one of isophorone diisocyanate, toluene diisocyanate and diphenylmethane diisocyanate; the polyglycol monomer is polycaprolactone diol, One of polytetrahydrofuran ether glycol and polybutylene adipate-1 and 4-butanediol ester glycol; the chain extender is dihydroxydiethylthiuram disulfide and bis(2-hydroxyethyl ) disulfide; the cross-linking agent is 5,10,15,20-tetrakis (4-hydroxyphenyl) porphyrin and 5,10,15,20-tetrakis (4-aminophenyl) A type of porphyrin.

Step 3: In terms of parts by mass, add 32 to 38 parts of the double bond-terminated polyurethane emulsion, 4.6 to 5.9 parts of butyl acrylate, and 3.5 to 4.8 parts of the grafted double bond functionalized modified polyurethane emulsion. Stir and mix the wall carbon nanotubes and 21 to 25 parts of the organic solvent under nitrogen protection. Add 12 to 15 parts of the RAFT chain transfer agent dissolved in the organic solvent dropwise. Stir and react at 60 to 70°C for 2 to 3 hours, and keep it warm for 4 hours. , cooled to room temperature and discharged, to obtain multi-walled carbon nanotube modified polyurethane acrylate emulsion; wherein, the RAFT chain transfer agent is 2-cyanoisopropyl dithiobenzoate, pyrrolidine dithioamino One of allyl formate and 2-methyl-2-[(dodecylthiocarbonylthiocarbonyl)thio]propionic acid; preferably, the RAFT chain in the RAFT chain transfer agent dissolved in the organic solvent The mass fraction of transfer agent is 1%.

It should be noted that the organic solvent described in steps 2 and 3 is one of chloroform, ethyl acetate, butyl acetate, toluene, acetone, tetrahydrofuran, xylene and cyclohexanone.

Step 4: Mix 25 to 30 parts of an ethanol solution with a concentration of 100 mg/L metal ions and 20 to 25 parts of the multi-walled carbon nanotube-modified polyurethane acrylate emulsion in terms of parts by mass, and stir continuously at room temperature. React for 24 hours to obtain a self-healing elastomer emulsion in which metal coordination bonds and dynamic covalent bonds interact; wherein the metal ions are one of iron ions, nickel ions, copper ions, cobalt ions, manganese ions and zinc ions. .

Step 5. Pour the self-healing elastomer solution that interacts with metal coordination bonds and dynamic covalent bonds into a polytetrafluoroethylene membrane, dry it at room temperature for 3 days, and then lay the viscous product with a vacuum pump laminating machine. , a smooth and flat film is obtained, that is, a self-healing elastomer film in which metal coordination bonds and dynamic covalent bonds interact is obtained; wherein, the self-healing elastomer film in which metal coordination bonds and dynamic covalent bonds interact is The polyurethane acrylate elastomer.

Preparation principle:

The preparation method of polyurethane acrylate elastomer of the present invention utilizes carboxylated multi-walled carbon nanotubes and hydroxypropyl acrylate to carry out esterification reaction. Since the carboxylated carbon nanotubes contain a large number of carboxyl groups, the hydroxypropyl acrylate contains Hydroxyl, during the esterification reaction, the carboxyl group and the hydroxyl group combine to form water, and the esterification reaction is a reversible reaction; by adding anhydrous sodium sulfate, anhydrous sodium sulfate is used to absorb the water generated by the combination of the carboxyl group and the hydroxyl group, so that the esterification reaction Keep going forward to obtain multi-walled carbon nanotubes functionalized with grafted double bonds; by adding hydroquinone as a polymerization inhibitor, it is possible to avoid hydroxypropyl acrylate and grafted double bonds under high temperature conditions. The self-polymerization of functionalized modified multi-walled carbon nanotubes can also avoid the copolymerization between hydroxypropyl acrylate and grafted double bond functional modification.

Secondly, the diisocyanate monomer contains an isocyanate group, which can perform nucleophilic addition with the terminal hydroxyl group in the polyglycol monomer to form a urethane, thereby obtaining a polyurethane prepolymer; by adding dibutyltin dilaurate as Catalyst to effectively increase the rate of nucleophilic addition reaction; add a chain extender containing hydroxyl and disulfide bonds to introduce disulfide bonds into the polyurethane prepolymer molecular chain, and at the same time expand the molecular weight of the polyurethane prepolymer; use Porphyrin cross-linking agents containing hydroxyl groups or amino groups can react with isocyanate groups, thereby causing the polyurethane prepolymer molecular chains to form a cross-linked network structure; at the same time, porphyrin ligands are introduced into the polyurethane prepolymer molecular chains; utilizing The hydroxyl group in hydroxyethyl acrylate reacts with the isocyanate group to introduce double bonds into the molecular chain segments of the polyurethane prepolymer to obtain a double bond-terminated polyurethane emulsion.

Double bond-terminated polyurethane emulsion, double bond-grafted multi-walled carbon nanotubes, and butyl acrylate are used to perform reversible addition-fragmentation chain transfer radical polymerization under the action of RAFT reagent, so that the degree of polymerization of the polymerization reaction can be effectively controlled. A polyurethane acrylate containing multi-walled carbon nanotubes, disulfide bonds and porphyrin ligands with a narrowed molecular weight distribution is obtained; in addition, a polyurethane acrylate containing multi-walled carbon nanotubes, disulfide bonds and porphyrin ligands is obtained. The porphyrin ligand interacts with the coordinating metal ion through chelation, and finally forms a metal coordination bond on the polyurethane acrylate molecular chain segment.

The polyurethane acrylate elastomer prepared by the method for preparing the polyurethane acrylate elastomer of the present invention has the characteristics of controllable molecular weight, excellent mechanical strength and toughness, and self-healing; the elastomer material can be used as a self-healing material. Stretched conductive devices have potential application prospects in the fields of surface coating protection, biomedical materials, flexible wearable electronics, lithium batteries, aerospace and other fields; wherein, the molecular weight of the polyurethane acrylate elastomer is 62820 to 64430; when When the film-like polyurethane acrylate elastomer breaks, it can achieve a self-healing efficiency of 85% to 90% under visible light exposure for 12 to 24 hours, and can reach 100% under ultraviolet light exposure for 0.5 to 1 hour. Self-healing efficiency; the tensile strength of the polyurethane acrylate elastomer is 46.6-58.6MPa, and the elongation at break is 1263%-1585%.

Example 1

This Example 1 provides a method for preparing polyurethane acrylate elastomer, which includes the following steps:

Step 1. Mix 5.2g carboxylated multi-walled carbon nanotubes, 21.6g hydroxypropyl acrylate, 0.54g hydroquinone, 11g anhydrous sodium sulfate and 41.6g methyl isoamyl ketone at room temperature under _N2 protection with 82kHz ultrasonic power Ultrasonic for 0.52h, then raise the temperature to 100°C, stir at constant temperature for 24h, add 106g of absolute ethanol for dilution, filter through a polyvinylidene fluoride membrane with a pore size of 0.22μm, wash the filter cake three times with deionized water, and place the resulting filter cake at 50 ℃ vacuum drying for 24 hours to obtain grafted double bond functionalized multi-walled carbon nanotubes.

Step 2. Stir and mix 17.8g of dried isophorone diisocyanate, 21.8g of polycaprolactone diol monomer and 25.9g of ethyl acetate at 80°C under _N2 protection, and add 0.2g of laurel. React with dibutyltin acid for 0.6h, add 1.7g and react for 0.6h, then add 0.78g of 5,10,15,20-tetrakis(4-hydroxyphenyl)porphyrin for 0.6h, keep the temperature for 2.2h, and cool to 60°C. Add 30g of ethyl acetate and 3.9g of hydroxyethyl acrylate to obtain a double bond-terminated polyurethane emulsion.

Step 3. Stir 32.8g double bond-terminated polyurethane solution, 4.9g butyl acrylate, 3.8g grafted double bond functionalized modified multi-walled carbon nanotubes and 22g ethyl acetate under N ₂ protection and mix evenly. Add 12.5g of 1% 2-cyanoisopropyl dithiobenzoate dissolved in ethyl acetate dropwise, stir and react at 63°C for 2.2h, keep incubated for 4h, cool to room temperature and discharge, to obtain modified multi-walled carbon nanotubes of polyurethane acrylic emulsion.

Step 4. 25.7g of 100mg/L iron ion ethanol solution and 21g of multi-walled carbon nanotube modified polyurethane acrylate emulsion were reacted with continuous stirring at room temperature for 24 hours to obtain the self-healing interaction between metal coordination bonds and dynamic covalent bonds. Elastomer lotion.

Step 5. Pour the self-healing elastomer solution that interacts with metal coordination bonds and dynamic covalent bonds into a polytetrafluoroethylene membrane, dry it at room temperature for 3 days, and then lay the viscous product with a vacuum pump laminating machine. , a smooth and flat film is obtained, that is, the polyurethane acrylate elastomer is obtained.

Example 2

This Example 2 provides a method for preparing a polyurethane acrylate elastomer, which includes the following steps:

Step 1. Mix 6.4g carboxylated multi-walled carbon nanotubes, 24.6g hydroxypropyl acrylate, 0.69g hydroquinone, 13g anhydrous sodium sulfate and 44.8g methyl isoamyl ketone at room temperature under _N2 protection with 89kHz ultrasonic power Ultrasonic for 0.7h, then raise the temperature to 100°C, stir at constant temperature for 24h, add 120g of absolute ethanol to dilute, filter through a polyvinylidene fluoride membrane with a pore size of 0.22μm, wash the filter cake three times with deionized water, and place the resulting filter cake at 50 ℃ vacuum drying for 24 hours to obtain grafted double bond functionalized multi-walled carbon nanotubes.

Step 2. Stir and mix 20g of dried toluene diisocyanate, 30g of polytetrahydrofuran ether glycol monomer and 29g of chloroform at 80°C under _N2 protection. Add 0.3g of dibutyltin dilaurate and react for 0.7h. Add 1.9 g of diethylthiuram dihydroxydisulfide for 0.7h, then add 0.83g of 5,10,15,20-tetrakis(4-hydroxyphenyl)porphyrin for 0.7h, keep the reaction for 2.5h, and cool to 60℃ , add 34g chloroform, add 4.7g hydroxyethyl acrylate, and obtain a double bond-terminated polyurethane emulsion.

Step 3. Stir and mix 34.8g double bond-terminated polyurethane solution, 5.2g butyl acrylate, 4.2g grafted double bond functionalized multi-walled carbon nanotubes and 23g chloroform under N ₂ protection, and add dropwise. 13.4g of 1% allyl pyrrolidine dithiocarbamate was dissolved in chloroform, stirred and reacted at 65°C for 2.4h, kept for 4h, cooled to room temperature and discharged, to obtain a multi-walled carbon nanotube modified polyurethane acrylate emulsion.

Step 4. 26.8g of 100mg/L nickel ion ethanol solution and 22g of multi-walled carbon nanotube modified polyurethane acrylate emulsion were reacted with continuous stirring at room temperature for 24 hours to obtain the self-healing interaction between metal coordination bonds and dynamic covalent bonds. Elastomer lotion.

Step 5. Pour the self-healing elastomer solution that interacts with metal coordination bonds and dynamic covalent bonds into a polytetrafluoroethylene membrane, dry it at room temperature for 3 days, and then lay the viscous product with a vacuum pump laminating machine. , a smooth and flat film is obtained, that is, the polyurethane acrylate elastomer is obtained.

Example 3

This Example 3 provides a method for preparing polyurethane acrylate elastomer, which includes the following steps:

Step 1. Mix 7.2g carboxylated multi-walled carbon nanotubes, 27.6g hydroxypropyl acrylate, 0.82g hydroquinone, 14g anhydrous sodium sulfate and 47.8g methyl isoamyl ketone at room temperature under _N2 protection with 92kHz ultrasonic power Ultrasonic for 0.8h, then raise the temperature to 100°C, stir at constant temperature for 24h, add 130g of absolute ethanol to dilute, filter through a polyvinylidene fluoride membrane with a pore size of 0.22μm, wash the filter cake three times with deionized water, and place the resulting filter cake at 50 ℃ vacuum drying for 24 hours to obtain grafted double bond functionalized multi-walled carbon nanotubes.

Step 2. Stir 22g of dried diphenylmethane diisocyanate, 40g of 1,4-butanediol adipate diol monomer and 32g of cyclohexanone at 80°C under N ₂ protection, and add 0.4g dibutyltin dilaurate was reacted for 0.8h, 2.0g bis(2-hydroxyethyl) disulfide was added and reacted for 0.8h, and then 0.9g 5,10,15,20-tetrakis(4-aminophenyl)porphyrin was added The pholine reaction was carried out for 0.8h, the heat preservation reaction was carried out for 2.7h, the temperature was lowered to 60°C, 36g of cyclohexanone was added, and 6.2g of hydroxyethyl acrylate was added to obtain a double bond-terminated polyurethane emulsion;

Step 3. Stir 36.2g of double bond-terminated polyurethane solution, 5.5g of butyl acrylate, 4.5g of grafted double bond functionalized multi-walled carbon nanotubes and 24g of cyclohexanone under N ₂ protection until evenly mixed. Add 14.2g of 1% 2-methyl-2-[(dodecylthiocarbonylthiocarbonyl)thio]propionic acid dissolved in cyclohexanone dropwise, stir and react at 67°C for 2.7h, keep warm for 4h, cool to room temperature and discharge. , obtain multi-walled carbon nanotube modified polyurethane acrylate emulsion;

Step 4. 28.3g of 100mg/L copper ion ethanol solution and 23.7g of multi-walled carbon nanotube modified polyurethane acrylate emulsion were reacted with continuous stirring at room temperature for 24 hours to obtain the natural interaction between metal coordination bonds and dynamic covalent bonds. Repair Elastomer Lotion;

Step 5. Pour the self-healing elastomer solution that interacts with metal coordination bonds and dynamic covalent bonds into a polytetrafluoroethylene membrane, dry it at room temperature for 3 days, and then lay the viscous product with a vacuum pump laminating machine. , a smooth and flat film is obtained, that is, the polyurethane acrylate elastomer is obtained.

Example 4

This Example 4 provides a method for preparing polyurethane acrylate elastomer, which includes the following steps:

Step 1. Ultrasound 7.8g carboxylated multi-walled carbon nanotubes, 29.4g hydroxypropyl acrylate, 0.96g hydroquinone, 14.7g anhydrous sodium sulfate and 49.5g methyl isoamyl ketone at room temperature and 98kHz under _N protection. Power ultrasonic for 0.9h, then raise the temperature to 100°C, stir at constant temperature for 24h, add 146g of absolute ethanol for dilution, filter through a polyvinylidene fluoride membrane with a pore size of 0.22μm, wash the filter cake three times with deionized water, and place the resulting filter cake in After vacuum drying at 50°C for 24 hours, grafted double bond functionalized multi-walled carbon nanotubes were obtained.

Step 2. Stir and mix 24g of dried isophorone diisocyanate, 44g of 1,4-butanediol adipate diol monomer and 34g of toluene at 80°C under _N2 protection, and add 0.46g Dibutyltin dilaurate was reacted for 0.9h, 2.07g of bis(2-hydroxyethyl) disulfide was added for 0.9h, and then 0.95g of 5,10,15,20-tetrakis(4-aminophenyl)porphyrin was added for reaction. 0.9h, heat preservation reaction for 2.9h, cool to 60°C, add 38g of toluene, and add 7.4g of hydroxyethyl acrylate to obtain a double bond-terminated polyurethane emulsion.

Step 3. Stir and mix 37.6g double bond-terminated polyurethane solution, 5.8g butyl acrylate, 4.7g grafted double bond functionalized multi-walled carbon nanotubes and 24.6g toluene under N ₂ protection, drop by drop. Add 14.8g of 1% 2-methyl-2-[(dodecylthiocarbonylthiocarbonyl)thio]propionic acid dissolved in toluene, stir the reaction at 69°C for 2.9h, keep it warm for 4h, cool to room temperature and discharge, to obtain poly Wall carbon nanotube-modified polyurethane acrylate emulsions.

Step 4. 29.8g of 100mg/L manganese ion ethanol solution and 24.8g of multi-walled carbon nanotube modified polyurethane acrylate emulsion were reacted with continuous stirring at room temperature for 24 hours to obtain the natural interaction between metal coordination bonds and dynamic covalent bonds. Repair Elastomer Lotion.

Step 5. Pour the self-healing elastomer solution that interacts with metal coordination bonds and dynamic covalent bonds into a polytetrafluoroethylene membrane, dry it at room temperature for 3 days, and then lay the viscous product with a vacuum pump laminating machine. , a smooth and flat film is obtained, that is, the polyurethane acrylate elastomer is obtained.

Comparative example 1

In Comparative Example 1, except that grafted double bond functionalized modified multi-walled carbon nanotubes are not prepared and used, other operations are the same as Example 1, and the detailed process will not be described again here.

Comparative example 2

In Comparative Example 2, except that diethylthiuram dihydroxydisulfide is not added, other operations are the same as in Example 1, and the detailed process will not be repeated here.

Comparative example 3

In Comparative Example 3, except that 5,10,15,20-tetrakis(4-hydroxyphenyl)porphyrin is not added, other operations are the same as Example 1, and the detailed process will not be repeated here.

Comparative example 4

In Comparative Example 4, 12.5 g of 1% azobisisobutyronitrile dissolved in ethyl acetate was used instead of 2-cyanoisopropyl dithiobenzoate. Other operations were the same as in Example 1. The detailed process is not shown here. Again.

Performance Testing:

The products prepared in Examples 1-4 and Comparative Examples 1-4 of the present invention were subjected to molecular weight test, mechanical property test and self-healing performance test.

(1) Molecular weight test: Use Japanese Shimadzu aqueous gel permeation chromatography (GPC) to measure relative molecular mass and PDI. Use PEG standard polymer to calibrate the GPC instrument, and use the calibration curve to determine the weight average molecular weight and PDI of the polymer.

(2) Mechanical property test: Use an electronic universal material testing machine, test temperature 25°C, tensile rate 500mm/min, test at least 5 specimens in each group, and take the tensile strength and elongation at break of each group of test specimens. average of.

(3) Self-healing performance test: The tensile spline is cut from the middle with a blade, and then closely connected. The cut pieces are irradiated with visible light at room temperature for 12h, 24h and ultraviolet light (wavelength 230~380nm) for 0.5h and 1h respectively. The spline performs self-healing, and the tensile strength ratio before and after fracture is used to characterize the corresponding self-healing efficiency.

Test Results:

The molecular weight, mechanical properties and self-healing performance test results of the films prepared in Examples 1 to 4 and the films prepared in Comparative Examples 1 to 4 are listed in Table 1.

Table 1 Test results of Examples and Comparative Examples

From the performance test results in Table 1 above, it can be seen that the molecular weight of the polyurethane acrylate elastomer prepared in Examples 1-4 is between 62820 and 64430, the PDI is between 1 and 2, and has a controllable molecular weight; when the film-like polyurethane acrylate elastomer When the ester elastomer breaks, the film that is closely connected after the break can reach a self-healing efficiency of 85.2% to 86.8% after being exposed to visible light for 12 to 24 hours; after being exposed to ultraviolet light for 0.5 to 1 hour, it can achieve 100% self-healing efficiency. Efficiency, the elastomer also has a tensile strength as high as 46.6~58.6MPa and an elongation at break of 1263%~1585%, and has excellent mechanical properties and self-healing properties.

It should be noted that, as can be seen from Example 1 and Comparative Example 1, chemical bonding can be achieved by introducing multi-walled carbon nanotubes functionalized with grafted double bonds into the polyurethane acrylate bomb described in Example 1. , effectively improving the mechanical properties of the film; it can be seen from Example 1, Comparative Example 2 and Comparative Example 3 that the introduction of disulfide bonds (dynamic covalent bonds) and porphyrin metal coordination bonds into the elastomer is the best way to achieve the goal of the elastomer film. The key factor of self-healing performance; it can be seen from Example 1 and Comparative Example 4 that the molecular weight distribution of the polymer obtained by using reversible addition-fragmentation chain transfer radical polymerization (RAFT) technology is narrower than that of conventional free radical copolymerization. Better mechanical properties.

The polyurethane acrylate elastomer and its preparation method and application of the present invention first utilize carboxylated multi-walled carbon nanotubes and hydroxypropyl acrylate to perform an esterification reaction to obtain grafted double bond functionally modified multi-walled carbon nanotubes. tube, secondly use diisocyanate monomer and polyglycol monomer to perform nucleophilic addition reaction, and then add hydroxyethyl acrylate to introduce double bonds to obtain a double bond-terminated polyurethane emulsion; then use the double bond-terminated polyurethane emulsion with Butyl acrylate and multi-walled carbon nanotubes functionalized with grafted double bonds undergo reversible addition-fragmentation chain transfer radical polymerization to obtain multi-walled carbon nanotube-modified polyurethane acrylate, which is finally introduced into the polymer molecular chain. The coordinated metal ions are dried to obtain a self-healing elastomer in which metal coordination bonds and dynamic covalent bonds interact; the elastomer has the characteristics of controllable molecular weight, excellent mechanical strength and toughness, and self-healing. This material It has potential application prospects in the fields of surface coating protection, biomedical materials, flexible wearable electronics, lithium batteries, and aerospace.

The above embodiment is only one of the ways to realize the technical solution of the present invention. The scope of protection claimed by the present invention is not only limited by this embodiment, but also includes any technical scope disclosed by the present invention. Changes, substitutions and other implementations may be easily imagined by those skilled in the art.

Claims (10)

1. A method for preparing polyurethane acrylate elastomer, which is characterized in that it includes: Carboxylated multi-walled carbon nanotubes are used to perform an esterification reaction with hydroxypropyl acrylate to obtain multi-walled carbon nanotubes functionalized with grafted double bonds; Utilize diisocyanate monomer and polyglycol monomer to perform a nucleophilic addition reaction, and then add hydroxyethyl acrylate to introduce double bonds to obtain a double bond-terminated polyurethane emulsion; Utilizing the double bond-terminated polyurethane emulsion, butyl acrylate and the grafted double bond functionalized modified multi-walled carbon nanotubes, the multi-walled carbon nanotubes modified by reversible addition-fragmentation bond transfer radical polymerization are obtained. Resistant polyurethane acrylate emulsion; Coordinated metal ions are introduced into the multi-walled carbon nanotube modified polyurethane acrylate emulsion and dried to obtain the polyurethane acrylate elastomer. 2. A method for preparing polyurethane acrylate elastomer according to claim 1, characterized in that carboxylated multi-walled carbon nanotubes and hydroxypropyl acrylate are used to perform an esterification reaction to obtain grafted double bond functional modification. The process of producing multi-walled carbon nanotubes is as follows: Carboxylated multi-walled carbon nanotubes, hydroxypropyl acrylate, hydroquinone, anhydrous sodium sulfate and methyl isoamyl ketone were ultrasonicated at room temperature under nitrogen protection; then the temperature was raised to the preset temperature, and at the preset temperature Stir at a constant temperature; then add absolute ethanol for dilution, and filter to obtain a filter cake; wash and dry the filter cake to obtain the grafted double bond functionalized multi-walled carbon nanotubes. 3. The preparation method of a kind of polyurethane acrylate elastomer according to claim 2, characterized in that carboxylated multi-walled carbon nanotubes, hydroxypropyl acrylate, hydroquinone, anhydrous sodium sulfate and methyl isopropyl The mass ratio of pentanone is: (5～8):(20～30):(0.5～1):(10～15):(40～50). 4. The preparation method of a kind of polyurethane acrylate elastomer according to claim 1, characterized in that, diisocyanate monomer and polyglycol monomer are utilized to carry out nucleophilic addition reaction, and then hydroxyethyl acrylate is added to The process of introducing double bonds to obtain double bond-terminated polyurethane emulsion is as follows: Mix diisocyanate monomer, polyglycol monomer and organic solvent, add dibutyltin dilaurate for reaction, then add chain extender and cross-linking agent for reaction, and then add organic solvent and hydroxyethyl acrylate to obtain the result The double bond-terminated polyurethane emulsion. 5. The preparation method of a kind of polyurethane acrylate elastomer according to claim 4, characterized in that the diisocyanate monomer is isophorone diisocyanate, toluene diisocyanate and diphenylmethane diisocyanate. One; the polyglycol monomer is one of polycaprolactone glycol, polytetrahydrofuran ether glycol, polyadipic acid-1 and 4-butylene glycol ester glycol; the chain extension The agent is one of dihydroxythiuram disulfide and bis(2-hydroxyethyl) disulfide; the cross-linking agent is 5,10,15,20-tetrakis(4-hydroxyphenyl) ) porphyrin and 5,10,15,20-tetrakis (4-aminophenyl) porphyrin. 6. The preparation method of a kind of polyurethane acrylate elastomer according to claim 1, characterized in that, the double bond-terminated polyurethane emulsion, butyl acrylate and the grafted double bond functionalized modified polyurethane emulsion are used. The process of obtaining multi-wall carbon nanotube-modified polyurethane acrylate emulsion through reversible addition-fragmentation bond transfer radical polymerization of wall carbon nanotubes is as follows: Mix the double bond-terminated polyurethane emulsion, butyl acrylate, the grafted double bond functionalized multi-walled carbon nanotubes and the organic solvent evenly, then add RAFT chain transfer agent to stir the reaction, keep warm, and cool to room temperature. The material is discharged to obtain multi-walled carbon nanotube modified polyurethane acrylate emulsion. 7. The preparation method of a polyurethane acrylate elastomer according to claim 1, characterized in that, coordinated metal ions are introduced into the multi-walled carbon nanotube modified polyurethane acrylate emulsion and dried to obtain The process of the polyurethane acrylate elastomer is as follows: After mixing the ethanol solution of metal ions and the multi-walled carbon nanotube modified polyurethane acrylate emulsion, the reaction is continued with stirring to obtain a self-healing elastomer emulsion; the self-healing elastomer emulsion is dried to obtain the polyurethane Acrylic elastomer. 8. The preparation method of polyurethane acrylate elastomer according to claim 7, wherein the metal ion is one of iron ions, nickel ions, copper ions, cobalt ions, manganese ions and zinc ions. . 9. A polyurethane acrylate elastomer, characterized in that it is prepared by the preparation method of a polyurethane acrylate elastomer according to any one of claims 1 to 8; Among them, the molecular weight of the polyurethane acrylate elastomer is 62820 to 64430; when the film-like polyurethane acrylate elastomer breaks, it can achieve a self-healing efficiency of 85.2% to 86.8% under visible light irradiation for 12 to 24 hours. , can achieve 100% self-healing efficiency under the condition of 0.5-1h irradiation under ultraviolet light; the tensile strength of the polyurethane acrylate elastomer is 46.6-58.6MPa, and the elongation at break is 1263%-1585%. 10. Application of a polyurethane acrylate elastomer as claimed in claim 9, characterized in that it is used as a self-healing stretchable conductive device.