Polyacrylate / PDA-Cu nano composite material as well as preparation method and application thereof

Abstract

The invention discloses a polyacrylate / PDA-Cu nano composite material as well as a preparation method and application thereof. The method comprises the following steps: dissolving dopamine hydrochloride in a tris (hydroxymethyl) aminomethane aqueous solution, adjusting the pH value to 8.5 by using concentrated hydrochloric acid, and stirring for reaction to obtain the polydopamine nanoparticles. The preparation method comprises the following steps: dispersing cupric acetate in an ethanol solution, adding PDA nanoparticles, carrying out ultrasonic stirring, standing, collecting a precipitate, adding the precipitate into an ethanol solution of sodium hypophosphite, carrying out reflux condensation at 80 DEG C for 30 min, and carrying out alcohol and water alternate centrifugation and drying treatment to obtain the PDA-Cu nanoparticles. And the obtained PDA-Cu nano particles are physically blended with a polyacrylate emulsion. The prepared PDA-Cu nano composite material is simple in preparation process, safe and environmentally friendly, the obtained nano composite material has a remarkable inhibition effect on growth of aspergillus niger, and the moisture permeability of a leather sample after coating is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of functional leather finishing agent, and particularly relates to a polyacrylate / PDA-Cu nanocomposite material, a preparation method and application thereof. BACKGROUND

[0002] Leather, as a bio-based material from animal skin, has always occupied an important position in daily consumer goods due to its excellent comfort, breathability and durability. However, the protein and fat components contained in leather products can easily become a nutrient matrix for the growth and rapid reproduction of microorganisms. At the same time, its unique collagen fiber network structure and hygroscopicity also provide ideal conditions for the attachment, growth and massive proliferation of microorganisms, ultimately leading to the formation of biofilm. Therefore, how to effectively inhibit the reproduction of microorganisms on the surface of leather has always been the focus of research in this field. Polyacrylate finishing agents are widely used in the field of leather coating due to their good film-forming properties, economical cost and excellent transparency. However, this type of finishing agent usually does not have antifungal function, especially in the humid environment of the south, which can easily lead to the growth and spread of microorganisms on the surface of leather products, not only affecting the appearance and use performance of the products, but also seriously endangering human health. In addition, polyacrylate coating has a dense film, poor water vapor permeability, and is difficult to discharge human sweat in time, resulting in poor wearing comfort and low hygiene performance. SUMMARY

[0003] The present application aims to provide a polyacrylate / PDA-Cu nanocomposite material, a preparation method and application thereof, which are used to solve the above technical problems of ordinary polyacrylate finishing agents. The leather finishing agent prepared by the method of the present application significantly improves the antifungal performance and hygiene performance of leather.

[0004] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows: A preparation method of a polyacrylate / PDA-Cu nanocomposite material, specifically comprising the following steps: Step one: first, dissolve dopamine hydrochloride in a tris-hydroxymethyl aminomethane aqueous solution, adjust the pH to 8.5 with concentrated hydrochloric acid, and perform stirring reaction. After that, use alcohol and water to perform alternating centrifugation, freeze-drying treatment, and obtain PDA nanoparticles; Step two: disperse copper acetate in an ethanol solution, add the PDA nanoparticles obtained in step one, perform ultrasonic stirring treatment for a period of time, and after the reaction is completed, stand for 12 hours and collect the precipitate. Then, add it to a sodium hypophosphite ethanol solution, perform condensation reflux at 80°C for 30 minutes, perform alternating centrifugation of alcohol and water, and perform drying treatment to obtain PDA-Cu nanoparticles; Step three: the PDA-Cu nanoparticles obtained in step two are dispersed into deionized water, and then physically blended with a polyacrylate emulsion; mechanical stirring is performed in a water bath at 60-100 DEG C, to obtain a polyacrylate / PDA-Cu nanocomposite.

[0005] Preferably, in step one, the stirring temperature is 25-30 DEG C, and the stirring time is 20-30 h.

[0006] Preferably, in step two, the mass ratio of PDA to copper acetate is 1:150-1:75, the ultrasonic time is 20-40 min, and the stirring time is 2-3 h.

[0007] Preferably, in step three, the PDA-Cu accounts for 1.5%-2.5% of the solid content of the polyacrylate emulsion, the ultrasonic time is 10-30 min, and the stirring time is 2-8 h.

[0008] A polyacrylate / PDA-Cu nanocomposite prepared by any one of the above preparation methods.

[0009] Use of a polyacrylate / PDA-Cu nanocomposite as described above as a leather finishing agent in mold-proof and moisture-permeable leather.

[0010] The present application has the following advantages: The polyacrylate / PDA-Cu nanocomposite preparation method provided by the present application uses polydopamine, a biomass material with excellent biocompatibility, biodegradability and environmental friendliness, which is rich in functional groups such as catechol and amino groups with strong reducing properties on the surface, and can convert Cu 2＋ into Cu nanoparticles, while achieving uniform loading of Cu nanoparticles on the surface of polydopamine. This technology not only retains the biocompatibility and structure regulation ability of PDA, but also imparts high antibacterial activity to the material through Cu; in addition, the PDA-Cu nanoparticles have a large specific surface area and excellent biocompatibility, which can effectively improve the water vapor permeability of the coating.

[0011] The PDA-Cu nanoparticles prepared by the present application are green and environmentally friendly, and have high efficient antibacterial function. Compared with other nano antibacterial materials, the PDA-Cu nanoparticles have simple preparation process, and do not need high temperature and high pressure conditions. The PDA-Cu nanoparticles have excellent antibacterial effect on gram-negative and gram-positive bacteria. The PDA-Cu nanoparticles are added into a polyacrylate emulsion to successfully prepare a mildew-proof and moisture-permeable polyacrylate / PDA-Cu nano composite leather finishing agent. The experimental results show that the obtained leather finishing agent can significantly inhibit the growth of Aspergillus niger. Compared with the leather sample coated with pure polyacrylate finishing agent, the moisture permeability of the leather sample coated with the composite finishing agent is increased by 19.14%. The technical scheme has important significance for greatly improving the mildew-proof performance, health performance and expanding the application range of the polyacrylate leather finishing agent. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 The figure is a comparison diagram of the mildew-proof performance of the polyacrylate / PDA-Cu material prepared by the present application and conventional materials on Aspergillus niger, (a) uncoated leather sample; (b) leather sample coated with pure polyacrylate leather finishing agent; (c) leather sample coated with polyacrylate / PDA-Cu nano composite leather finishing agent.

[0013] Figure 2 The figure is a comparison diagram of the moisture vapor permeability of the leather sample coated with the polyacrylate / PDA-Cu material prepared by the present application as a leather finishing agent and conventional finishing agents, 1-uncoated leather sample; 2-leather sample coated with pure polyacrylate leather finishing agent; 3-leather sample coated with polyacrylate / PDA-Cu nano composite leather finishing agent. DETAILED DESCRIPTION

[0014] The present application will be described in detail below in combination with specific embodiments.

[0015] The present application provides a polyacrylate / PDA-Cu nano composite material, a preparation method and application thereof. The preparation method comprises the following steps: Step one: first, dopamine hydrochloride is dissolved in a tris-hydroxymethyl aminomethane aqueous solution, and the pH is adjusted to 8.5 by using concentrated hydrochloric acid. Stirring is performed at a temperature of 25-30 DEG C for 20-30 h. The PDA nanoparticles are obtained by using alcohol and water for alternating centrifugation and freeze-drying treatment.

[0016] Step two: copper acetate is dispersed in an ethanol solution, and the PDA nanoparticles obtained in step one are added. Ultrasonic stirring is performed for a period of time. After the reaction is completed, the mixture is left to stand for 12 h, and the precipitate is collected. The precipitate is added into an ethanol solution of sodium hypophosphite, and condensation reflux is performed at 80 DEG C for 30 min. The PDA-Cu nanoparticles are obtained by using alcohol and water for alternating centrifugation and drying treatment. The mass ratio of PDA to copper acetate is 1:150-1:75. The ultrasonic time is 20-40 min, and the stirring time is 2-3 h.

[0017] Step three: the PDA-Cu nanoparticles obtained in step two were dispersed in deionized water, and then physically blended with a polyacrylate emulsion. Mechanical stirring was performed in a water bath at 60-100°C. The PDA-Cu accounted for 1.5-2.5% of the solid content of the polyacrylate emulsion. Ultrasonic treatment was performed for 10-30 min, and stirring was performed for 2-8 h. Thus, a polyacrylate / PDA-Cu nanocomposite was obtained.

[0018] Example 1 Step one: first, 1.92 g of dopamine hydrochloride was dissolved in a tris-hydroxymethyl aminomethane aqueous solution. The pH was adjusted to 8.5 with concentrated hydrochloric acid. The solution was stirred at room temperature for 24 h. The solution was centrifuged with alcohol and water at a speed of 8000 r / min. After freeze-drying for 24 h, PDA nanoparticles were obtained.

[0019] Step two: 2 g of copper acetate was dispersed in an ethanol solution. 20 mg of the PDA nanoparticles obtained in step one were added. After ultrasonic treatment for 30 min, the solution was stirred for 2 h. After the reaction was completed, the solution was allowed to stand for 12 h. The precipitate was collected. The precipitate was added to an ethanol solution of 1.78 g of sodium hypophosphite. The solution was condensed and refluxed at 80°C for 30 min. The solution was centrifuged with alcohol and water, and then dried to obtain PDA-Cu nanoparticles.

[0020] Step three: 0.07 g of the PDA-Cu nanoparticles obtained in step two were dispersed in 5 mL of deionized water. The solution was physically blended with 20 mL of a polyacrylate emulsion. Mechanical stirring was performed in a water bath at 60°C. Thus, a polyacrylate / PDA-Cu nanocomposite was obtained.

[0021] Example 2 Step one: first, 1.92 g of dopamine hydrochloride was dissolved in a tris-hydroxymethyl aminomethane aqueous solution. The pH was adjusted to 8.4 with concentrated hydrochloric acid. The solution was stirred at room temperature for 26 h. The solution was centrifuged with alcohol and water at a speed of 8000 r / min. After freeze-drying for 26 h, PDA nanoparticles were obtained.

[0022] Step two: 2.5 g of copper acetate was dispersed in an ethanol solution. 20 mg of the PDA nanoparticles obtained in step one were added. After ultrasonic treatment for 20 min, the solution was stirred for 2.5 h. After the reaction was completed, the solution was allowed to stand for 13 h. The precipitate was collected. The precipitate was added to an ethanol solution of 1.78 g of sodium hypophosphite. The solution was condensed and refluxed at 80°C for 25 min. The solution was centrifuged with alcohol and water, and then dried to obtain PDA-Cu nanoparticles.

[0023] Step 3: Take 0.12g of PDA-Cu nanoparticles obtained in Step 2 and disperse them in 5mL of deionized water. Then, physically mix them with 20mL of polyacrylate emulsion and mechanically stir them in a water bath at 70℃ to obtain polyacrylate / PDA-Cu nanocomposite material.

[0024] Example 3: Step 1: First, dissolve 1.92g of dopamine hydrochloride in an aqueous solution of tris(hydroxymethyl)aminomethane, adjust the pH to 8.6 with concentrated hydrochloric acid, and stir the reaction at room temperature for 22 hours. Centrifuge alternately with alcohol and water at a speed of 8000 r / min. After freeze-drying for 20 hours, PDA nanoparticles are obtained.

[0025] Step 2: Disperse 3g of copper acetate in an ethanol solution, add 20mg of PDA nanoparticles obtained in Step 1, sonicate for 35min and stir for 2h. After the reaction is complete, let stand for 14h and collect the precipitate. Add it to an ethanol solution of 1.78g of sodium hypophosphite and reflux at 80℃ for 35min. After alternating centrifugation with alcohol and water and drying, PDA-Cu nanoparticles are obtained.

[0026] Step 3: Take 0.15g of PDA-Cu nanoparticles obtained in Step 2 and disperse them in 5mL of deionized water. Then, physically mix them with 20mL of polyacrylate emulsion and mechanically stir them in a water bath at 80℃ to obtain polydopamine-copper nanocomposite material.

[0027] Example 3 is the best example.

[0028] like Figure 1 As shown, it is a comparison of the anti-mold performance of the polyacrylate / PDA-Cu nanocomposite material prepared in Example 3 as a leather finishing agent and the leather sample coated with pure polyacrylate leather finishing agent against Aspergillus niger. Compared with the uncoated leather sample, the PDA-Cu coated leather sample has a significant inhibitory effect on the growth of Aspergillus niger. like Figure 2 As shown, it is a comparison of the water vapor permeability of leather samples coated with the polyacrylate / PDA-Cu nanocomposite material prepared in Example 3 as a leather finishing agent and pure polyacrylate leather finishing agent. Compared with the leather sample coated with pure polyacrylate emulsion, the water vapor permeability of the PDA-Cu coated leather sample is increased by 20%.

[0029] The content of this invention is not limited to the embodiments listed. Any equivalent modifications made by those skilled in the art to the technical solutions of this invention by reading this specification are covered by the claims of this invention.

Claims

1. A method for preparing a polyacrylate / PDA-Cu nanocomposite, characterized in that, Specifically comprising the following steps: Step one: first, dopamine hydrochloride is dissolved in a tris-hydroxymethyl aminomethane aqueous solution, the pH is adjusted to 8.5 with concentrated hydrochloric acid, and the reaction is stirred. The alcohol and water are alternately centrifuged, and freeze-dried to obtain PDA nanoparticles; Step two: copper acetate is dispersed in an ethanol solution, the PDA nanoparticles obtained in step one are added, and the mixture is ultrasonically stirred for a period of time. After the reaction is completed, the mixture is allowed to stand for 12 h, and the precipitate is collected. The precipitate is added to an ethanol solution of sodium hypophosphite, and the mixture is condensed and refluxed at 80℃ for 30 min. The alcohol and water are alternately centrifuged and dried to obtain PDA-Cu nanoparticles; Step three: the PDA-Cu nanoparticles obtained in step two are dispersed in deionized water, and then physically blended with a polyacrylate emulsion. The mixture is mechanically stirred in a water bath at 60-100℃ to obtain a polyacrylate / PDA-Cu nanocomposite.

2. The method for preparing polyacrylate / PDA-Cu nanocomposite according to claim 1, characterized in that: In step one, the stirring temperature is 25-30℃, and the stirring time is 20-30 h.

3. The method for preparing a polyacrylate / PDA-Cu nanocomposite material according to claim 2, characterized in that: In step two, the mass ratio of PDA to copper acetate is 1:150-1:75, the ultrasonic time is 20-40 min, and the stirring time is 2-3 h.

4. The method for preparing a polyacrylate / PDA-Cu nanocomposite material according to claim 3, characterized in that: In step three, the PDA-Cu accounts for 1.5%-2.5% of the solid content of the polyacrylate emulsion, the ultrasonic time is 10-30 min, and the stirring time is 2-8 h.

5. A polyacrylate / PDA-Cu nanocomposite prepared by the method of any one of claims 1-4.

6. Use of the polyacrylate / PDA-Cu nanocomposite of claim 5 as a leather finishing agent in mold-proof and moisture-permeable leather.

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