Aniline modified liquid metal / polyurethane composite material and preparation method thereof

Abstract

The invention discloses an aniline modified liquid metal / polyurethane composite material and a preparation method thereof.The method comprises the steps that vinyl aniline is used as a reaction monomer to graft LM particles to obtain a primary structure unit, polyaniline grafted LM functional particles are prepared in a single molecule and dimer aniline chain extension polymerization mode, and the polyaniline grafted LM functional particles are used for preparing the aniline modified liquid metal / polyurethane composite material. The LM functional particles are used as copolymerization units of polyurethane elastomers, so that polyurethane conductive network construction with the LM functional particles as copolymerization sites is realized, and the aniline modified liquid metal / polyurethane composite material is obtained. According to the preparation method, the chemical activity of free radicals of gallium in liquid metal is activated by reasonably regulating and controlling ultrasonic process parameters, vinyl aniline monomers are grafted to the surfaces of liquid metal microspheres through Ga-C covalent bonds to prepare an organic conductive layer to replace conductive microspheres of a liquid metal microsphere self-oxidation film Ga2O3, and the compatibility of the liquid metal and polyurethane is effectively improved; the problem of high interface resistance of the liquid metal microspheres in the preparation process of the liquid metal / polyurethane composite material is solved.

Description

Technical Field

[0001] The invention relates to the field of gallium-based liquid metal composite materials, and in particular to an aniline-modified liquid metal / polyurethane composite material and a preparation method thereof. Background Art

[0002] Gallium-based liquid metal (LM) is a cutting-edge new material with high tensile deformation ability, excellent electrical (3.4-6.7×104S / cm), thermal (16.5-29.3W / m·K), low toxicity, safety and high stability. The Young's modulus of LM is 5-6 orders of magnitude lower than that of commonly used elastomers, and 10-12 orders of magnitude lower than that of common rigid conductive fillers such as metals and carbon materials, showing excellent high tensile properties. Liquid metal composites (LM composites, LMCs for short) can exert their own high deformation characteristics and maintain synchronous force deformation with elastomers, making them of important scientific value in the research and development of high-tensile and high-sensitivity sensing materials.

[0003] At present, the main method for preparing LMCs is to break LM into nanoparticles by mechanical force and disperse them in an elastomer matrix to obtain a composite material. However, studies have shown that when LM is broken into particles under mechanical force, it is very easy to spontaneously form a nanoscale passivation oxide layer (about 1-3nm in air environment, such as Figure 2 As shown; under vacuum conditions, it is about 0.7nm), and its main component is Ga 2 O 3 (Conductivity 10-6S / cm), this oxide layer causes the interface conductivity of LM particles to drop sharply, greatly reducing the intrinsic conductivity of LM fillers. For example, Majidi et al. confirmed that the insulation strength of LM / PVDF composite materials with a volume ratio of 40Vol% is still 1kV / mm, and even when it is increased to 80Vol%, the LM / PDMS composite material is still in an insulating state. It can be seen that the high interface resistance characteristics of LM particles have become a key issue for polymer-based conductive liquid metal composites. Summary of the invention

[0004] The purpose of the present invention is to provide an aniline-modified liquid metal / polyurethane composite material and a preparation method thereof in view of the deficiencies in the prior art. By designing a liquid metal particle comonomer, a new method for constructing a polyurethane conductive network with liquid metal particle reaction sites is realized, thereby avoiding the agglomeration problem caused by secondary processing, effectively improving the compatibility of liquid metal and polyurethane, and solving the problem of high interface resistance of liquid metal microspheres in the preparation process of the liquid metal / polyurethane composite material.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] The present invention provides a method for preparing an aniline-modified liquid metal / polyurethane composite material, comprising the following steps:

[0007] (1) taking a Ga-based liquid metal, wherein the Ga-based liquid metal comprises: 60-100 wt.% Ga, 0-25 wt.% In and 0-15 wt.% Sn;

[0008] (2) placing Ga-based liquid metal, vinylaniline and solvent in a reaction container at a mass ratio of 100:(20-40):(150-200), and performing ultrasonic treatment to obtain an ANI-g-LM particle solution;

[0009] (3) adding aniline and / or p-phenylenediamine and an initiator to the ANI-g-LM particle solution obtained in step (2), performing ultrasonic treatment, and adjusting the pH of the system to 5-7 with a low-concentration acid solution to obtain a PANI-g-LM particle solution;

[0010] (4) 60-90 parts by weight of polyether polyol, 30-40 parts by weight of diisocyanate, 80-100 parts by weight of the PANI-g-LM particle solution obtained in step (3) and 1-2 parts by weight of a catalyst are placed in a reaction container, stirred and mixed, and the temperature is raised to 80-90° C., and reacted at 80-90° C. for 3-4 hours to obtain an aniline-modified liquid metal / polyurethane composite material.

[0011] Furthermore, the Ga-based liquid metal is Ga, GaIn alloy, GaSn alloy or GaInSn alloy.

[0012] Furthermore, in the step (2), the vinylaniline is at least one of 2-vinylaniline, 3-vinylaniline, 4-vinylaniline and N,N-dimethyl-4-vinylaniline.

[0013] Furthermore, in the step (2), the ultrasonic power of the ultrasonic treatment is 250-400W, and the ultrasonic time is 0.5-1h.

[0014] Furthermore, in step (2), the solvent is at least one of N,N-dimethylformamide, N,N-dimethylacetamide, toluene, xylene and ethanol.

[0015] Furthermore, in the step (3), the mass ratio of aniline, p-phenylenediamine, initiator and ANI-g-LM particle solution is 2:(3-6):(1-2):10.

[0016] Furthermore, in the step (3), the mass ratio of aniline, initiator and ANI-g-LM particle solution is (5-10):(1-2):10.

[0017] Furthermore, in the step (3), the mass ratio of p-phenylenediamine, initiator and ANI-g-LM particle solution is (5-8):(1-2):10.

[0018] Furthermore, in step (3), the acid solution is at least one of a sulfuric acid solution, a hydrochloric acid solution or an oxalic acid solution with a concentration of 0.01-0.1 mol / L, and the initiator is at least one of potassium persulfate, ammonium persulfate and azobisisobutyronitrile.

[0019] Furthermore, in the step (3), the ultrasonic power of the ultrasonic treatment is 450-600W, and the ultrasonic time is 0.5-1h.

[0020] Furthermore, in step (4), the diisocyanate is at least one of isophorone diisocyanate, hexamethylene diisocyanate, p-phenylene diisocyanate, 1,3-diisobenzocyanate, and m-xylylene diisocyanate;

[0021] The polyether polyol is at least one of MN-3050D, ZSN-330, and GR-750, and the number average molecular weight of the polyether polyol is 1000 to 3000;

[0022] The catalyst is at least one of dibutyltin dilaurate, bismuth laurate and bismuth isooctanoate.

[0023] The present invention also provides an aniline-modified liquid metal / polyurethane composite material, which is prepared by the above-mentioned preparation method.

[0024] The present invention constructs an organic conductive layer on the surface of LM particles through organic covalent bonds, and prepares aniline-modified liquid metal / polyurethane composite materials by "covalent bond grafting → chain extension polymerization → in-situ copolymerization". The method uses ultrasound to activate the chemical activity of Ga as a means to design the primary structural unit of vinylaniline grafted LM particles, and then prepares zero-dimensional / one-dimensional nano-polyaniline grafted LM functional particles by single molecule and dimer aniline chain extension polymerization, and uses them as copolymerization reaction units of polyurethane elastomers, thereby realizing the construction of a conductive network with LM functional particles as copolymerization reaction sites, and finally obtaining a conductive aniline-modified liquid metal / polyurethane composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 TEM image of LM particles without ANI bonded;

[0026] Figure 2 TEM image of ANI-g-LM particles prepared in Example 1 of the present invention;

[0027] Figure 3 This is a SEM image of the ANI-g-LM particles prepared in Example 1 of the present invention;

[0028] Figure 4 This is a SEM image of the aniline-modified liquid metal / polyurethane composite material prepared in Example 1 of the present invention;

[0029] Figure 5 This is a mechanism diagram of the PANI-g-LM particles prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0030] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0031] Example 1

[0032] Aniline modified liquid metal / polyurethane composites were prepared by the following steps:

[0033] (1) taking a Ga-based liquid metal, wherein the Ga-based liquid metal contains 100 wt.% of Ga;

[0034] (2) Ga-based liquid metal, 2-vinylaniline and solvent are placed in a reaction container in a mass ratio of 100:20:150, and ultrasonic treatment is performed with a power of 300 W for 1 hour to activate the chemical activity of Ga free radicals, and vinylaniline is grafted onto the surface of LM particles through Ga-C covalent bonds to obtain ANI-g-LM particle solution; the solution is prepared from N,N-dimethylformamide and ethanol in a volume ratio of 1:3;

[0035] (3) adding aniline and ammonium persulfate to the ANI-g-LM particle solution, using 500 W ultrasonic wave for 0.4 hours, and adjusting the pH of the system to 6 using 0.1 mol / L sulfuric acid solution, wherein the mass ratio of aniline, ammonium persulfate and ANI-g-LM particle solution is 5:1:10, and obtaining a PANI-g-LM particle solution, and performing ultrasonic treatment for 40 minutes to obtain a PANI-g-LM particle solution;

[0036] (4) 60 parts by weight of polyether polyol MN-3050D (number average molecular weight 3000), 30 parts by weight of isophorone diisocyanate, 80 parts by weight of PANI-g-LM particle solution and 1.6 parts by weight of dibutyltin dilaurate were placed in a reaction container, stirred and mixed, and the temperature was raised to 85°C, and reacted at 85°C for 4 hours to obtain aniline-modified liquid metal / polyurethane composite material.

[0037] The electrical conductivity of the aniline-modified liquid metal / polyurethane composite material prepared in Test Example 1 is 550 S / cm.

[0038] Example 2

[0039] Aniline modified liquid metal / polyurethane composites were prepared by the following steps:

[0040] (1) Ga-based liquid metal is obtained, wherein the Ga-based liquid metal is a GaIn alloy containing 75 wt.% Ga and 25 wt.% In;

[0041] (2) Ga-based liquid metal, 4-vinylaniline and solvent are placed in a reaction container at a mass ratio of 100:40:200, and ultrasonic treatment is performed with a power of 300 W for 1 hour to activate the chemical activity of Ga free radicals, and vinylaniline is grafted onto the surface of LM particles through Ga-C covalent bonds to obtain ANI-g-LM particle solution; the solution is prepared from N,N-dimethylformamide and ethanol at a volume ratio of 1:3;

[0042] (3) adding p-phenylenediamine and potassium persulfate to the ANI-g-LM particle solution, using 500 W ultrasonic wave for 0.4 hours, and using 0.1 mol / L oxalic acid solution to adjust the pH of the system to 6, wherein the mass ratio of p-phenylenediamine, potassium persulfate and ANI-g-LM particle solution is 8:2:10, and a PANI-g-LM particle solution is obtained, and ultrasonic treatment is performed for 40 minutes to obtain a PANI-g-LM particle solution;

[0043] (4) 70 parts by weight of polyether polyol GR-750 (number average molecular weight 1000), 35 parts by weight of hexamethylene diisocyanate, 85 parts by weight of PANI-g-LM particle solution and 1 part by weight of bismuth laurate were placed in a reaction container, stirred and mixed, and the temperature was raised to 85°C, and reacted at 85°C for 4 hours to obtain aniline-modified liquid metal / polyurethane composite material.

[0044] The electrical conductivity of the aniline-modified liquid metal / polyurethane composite material prepared in Test Example 2 is 780 S / cm.

[0045] Example 3

[0046] Aniline modified liquid metal / polyurethane composites were prepared by the following steps:

[0047] (1) Ga-based liquid metal is obtained, wherein the Ga-based liquid metal is a GaInSn alloy containing 60-100 wt.% Ga, 15 wt.% In and 10 wt.%;

[0048] (2) Ga-based liquid metal, N,N-dimethyl-4-vinylaniline and solvent are placed in a reaction container in a mass ratio of 100:40:150, and ultrasonic treatment is performed for 1 hour using 300W power ultrasound to activate the chemical activity of Ga free radicals, and vinylaniline is grafted onto the surface of LM particles through Ga-C covalent bonds to obtain ANI-g-LM particle solution; the solution is prepared from N,N-dimethylformamide and ethanol in a volume ratio of 1:3;

[0049] (3) adding aniline, p-phenylenediamine and azobisisobutyronitrile to the ANI-g-LM particle solution, using 500W ultrasonic wave for 0.4 hours, and adjusting the pH of the system to 6 with 0.1 mol / L hydrochloric acid solution, wherein the mass ratio of aniline, p-phenylenediamine, azobisisobutyronitrile and ANI-g-LM particle solution is 2:4:1:10, and obtaining PANI-g-LM particle solution, and performing ultrasonic treatment for 40 minutes to obtain PANI-g-LM particle solution;

[0050] (4) 90 parts by weight of polyether polyol ZSN-330 (number average molecular weight 2000), 40 parts by weight of p-phenylene diisocyanate, 100 parts by weight of PANI-g-LM particle solution and 1 part by weight of bismuth isooctanoate were placed in a reaction container, stirred and mixed, and the temperature was raised to 85°C, and reacted at 85°C for 4 hours to obtain aniline-modified liquid metal / polyurethane composite material.

[0051] The electrical conductivity of the aniline-modified liquid metal / polyurethane composite material prepared in Test Example 3 is 1050 S / cm.

[0052] According to the disclosure of the above description, those skilled in the art to which the present invention belongs may also make appropriate changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should also fall within the scope of protection of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the present invention.

Claims

1. A method for preparing an aniline-modified liquid metal / polyurethane composite material, characterized in that: The steps include: (1) taking a Ga-based liquid metal, wherein the Ga-based liquid metal comprises: 60-100 wt.% Ga, 0-25 wt.% In and 0-15 wt.% Sn; (2) placing Ga-based liquid metal, vinylaniline and solvent in a reaction container at a mass ratio of 100:(20-40):(150-200), and performing ultrasonic treatment to obtain an ANI-g-LM particle solution; (3) adding aniline and / or p-phenylenediamine and an initiator to the ANI-g-LM particle solution obtained in step (2), performing ultrasonic treatment, and adjusting the pH of the system to 5-7 with a low-concentration acid solution to obtain a PANI-g-LM particle solution; (4) 60-90 parts by weight of polyether polyol, 30-40 parts by weight of diisocyanate, 80-100 parts by weight of the PANI-g-LM particle solution obtained in step (3) and 1-2 parts by weight of a catalyst are placed in a reaction container, stirred and mixed, and the temperature is raised to 80-90° C., and reacted at 80-90° C. for 3-4 hours to obtain an aniline-modified liquid metal / polyurethane composite material.

2. The method for preparing the aniline-modified liquid metal / polyurethane composite material according to claim 1, characterized in that: The Ga-based liquid metal is Ga, GaIn alloy, GaSn alloy or GaInSn alloy.

3. The method for preparing the aniline-modified liquid metal / polyurethane composite material according to claim 1, characterized in that: In the step (2), the vinylaniline is at least one of 2-vinylaniline, 3-vinylaniline, 4-vinylaniline and N,N-dimethyl-4-vinylaniline; The solvent is at least one of N,N-dimethylformamide, N,N-dimethylacetamide, toluene, xylene, and ethanol; The ultrasonic power of the ultrasonic treatment is 250-400W, and the ultrasonic time is 0.5-1h.

4. The method for preparing the aniline-modified liquid metal / polyurethane composite material according to claim 1, characterized in that: In the step (3), the mass ratio of aniline, p-phenylenediamine, initiator and ANI-g-LM particle solution is 2:(3-6):(1-2):

10.

5. The method for preparing the aniline-modified liquid metal / polyurethane composite material according to claim 1, characterized in that: In the step (3), the mass ratio of aniline, initiator and ANI-g-LM particle solution is (5-10):(1-2):

10.

6. The method for preparing the aniline-modified liquid metal / polyurethane composite material according to claim 1, characterized in that: The mass ratio of p-phenylenediamine, initiator and ANI-g-LM particle solution in the step (3) is (5-8):(1-2):

10.

7. The method for preparing the aniline-modified liquid metal / polyurethane composite material according to claim 1, characterized in that: In the step (3), the acid solution is at least one of a sulfuric acid solution, a hydrochloric acid solution or an oxalic acid solution with a concentration of 0.01-0.1 mol / L, and the initiator is at least one of potassium persulfate, ammonium persulfate and azobisisobutyronitrile.

8. The method for preparing the aniline-modified liquid metal / polyurethane composite material according to claim 1, characterized in that: The ultrasonic power of the ultrasonic treatment in step (3) is 450-600W, and the ultrasonic time is 0.5-1h.

9. The method for preparing the aniline-modified liquid metal / polyurethane composite material according to claim 1, characterized in that: In the step (4), the diisocyanate is at least one of isophorone diisocyanate, hexamethylene diisocyanate, p-phenylene diisocyanate, 1,3-diisophenyl cyanate, and m-phenylenediisocyanate; the polyether polyol is at least one of MN-3050D, ZSN-330, and GR-750, and the number average molecular weight of the polyether polyol is 1000 to 3000; and the catalyst is at least one of dibutyltin dilaurate, bismuth laurate, and bismuth isooctanoate.

10. An aniline-modified liquid metal / polyurethane composite material prepared by the method according to any one of claims 1 to 9.

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