CN113968950B

CN113968950B - Bactericidal glycol chain extender, preparation method thereof and application of bactericidal glycol chain extender in multifunctional synergistic antifouling waterborne polyurethane

Info

Publication number: CN113968950B
Application number: CN202111362163.0A
Authority: CN
Inventors: 张怡; 尹衍升; 葛涛; 路金林; 张志斌
Original assignee: Guangzhou Maritime University
Current assignee: Guangzhou Maritime University
Priority date: 2021-11-17
Filing date: 2021-11-17
Publication date: 2023-04-11
Anticipated expiration: 2041-11-17
Also published as: CN113968950A

Abstract

The invention provides a bactericidal glycol chain extender with a structural formula

The glycol chain extender is prepared by the following steps: dissolving dibromooctylpentanediol and 1, 2-benzisothiazole-3-ketone in a solvent, putting the solvent into a microwave reactor, reacting for 2212 hours at 22222 ℃, and purifying to obtain a diol chain extender containing a bactericidal group; the mol ratio of the dibromooctapentanediol to the 1, 2-benzisothiazol-3-one is 1.2. The invention also provides application of the glycol chain extender in multifunctional synergistic antifouling waterborne polyurethane. The bactericidal diol chain extender is applied to the preparation of the antifouling waterborne polyurethane, and bactericidal groups are introduced into the coating through covalent bonds, so that the environmental toxicity can be effectively reduced compared with a release antifouling coating, and the prepared antifouling waterborne polyurethane can be widely applied to the fields of textiles, plastics, medical treatment and health care and the like, particularly the field of marine antifouling; on the other hand, the method does not cause environmental pollution, can also reduce the production cost of products and save energy.

Description

Bactericidal glycol chain extender, preparation method thereof and application of bactericidal glycol chain extender in multifunctional synergistic antifouling waterborne polyurethane

Technical Field

The invention belongs to the field of high polymer materials, and particularly relates to a sterilization type glycol chain extender, a preparation method thereof and application thereof in multifunctional synergistic antifouling polyurethane.

Background

Biological fouling substances such as proteins, cells, microorganisms and aquatic organisms are easy to adhere and aggregate on the surfaces of daily supplies, building materials, biomedical materials, marine equipment and the like, a series of problems are brought to industries such as medical treatment, health, food, shipping and the like, and the health and property safety of human beings are seriously threatened. Wherein, marine biofouling increases the ship navigation resistance, blocks the marine engineering facilities, even causes the local perforation corrosion of the base material, and influences the service performance and the service life of the marine engineering facilities. In addition, the cleaning process of marine fouling substances can also cause biological invasion, epidemic propagation and the like to cause economic and social hazards. The antifouling paint can effectively prevent various pollutants from corroding and polluting the base material without influencing the performance of the base material, and is the most convenient and effective antifouling measure. The prior antifouling paint technology also depends heavily on the use of toxic bactericides, and poses serious threats to human beings and ecological environment. Therefore, the non-release environment-friendly polymer coating replaces the traditional release coating, is used for preventing marine organism fouling and reducing the harm to the marine ecological environment, and is the future development direction of the marine antifouling coating.

TABLE 1 Main types, structural characteristics and problems of the novel environmentally friendly antifouling paint

The existing novel antifouling paint mainly comprises fouling prevention type, fouling desorption type, sterilization type, degradation self-polishing paint and the like, and the main structural characteristics and the existing problems of the existing novel antifouling paint are shown in table 1. Among a plurality of antifouling paints, fouling desorption type paints with low surface energy such as organosilicon fluorine become a hotspot of the current antifouling paint research. The antifouling paint has low surface energy property, so that fouling is difficult to attach to the surface, even if the fouling is not firmly attached, the fouling is easy to fall off under the action of water flow or other external force, and the antifouling paint has great application potential in the fields of marine antifouling, medical health, public health and the like.

But the paint relying on a single antifouling mechanism cannot achieve the ideal antifouling effect. The low-surface-energy antifouling coating containing silicon and fluorine has an unobvious antifouling effect in a static state, is difficult to prevent growth of a mucus layer consisting of algae and bacteria, can only make microorganisms attached insecurely, needs to be cleaned regularly, and is difficult to remove once the attached organisms grow. Therefore, the low-surface-energy antifouling paint is blended with an antifouling agent 4, 5-dichloro-2-N-octyl-3-isothiazolinone (DCOIT) to realize slow release or grafting of the antifouling agent (triclosan, N- (2, 4, 6-trichlorophenyl) maleimide), quaternary ammonium salt and the like to construct a sterilization-fouling desorption type paint, the sterilization-fouling desorption type paint is applied to occasions with different requirements on antifouling aging, or hydrophilic polyethylene glycol (PEG), zwitterion and the like are introduced to construct a fouling-prevention desorption type paint, and the antifouling performance of the coating is further improved. However, even if the surface is sterilized and anti-adhesion, the fouling still grows for a long time, resulting in failure of antifouling. Therefore, a new idea of 'degradation antifouling' is provided by Zhanguang topic group of southern China university, a series of polyester type biodegradable high molecular base materials are developed, the surface of the coating can be continuously self-renewed through degradation, and the self-polishing antifouling purpose is achieved, but the antifouling activity of the structure is seriously dependent on the degradation performance of the coating. Therefore, the integration of multiple mechanisms to coordinate antifouling is a necessary development trend of antifouling coatings, and the interaction among multiple antifouling structures and the influence on the antifouling structures and activities of coatings are important problems to be solved urgently.

Disclosure of Invention

The invention aims to solve the technical problems, and provides a diol chain extender containing a bactericidal group, which can be applied to the preparation of waterborne polyurethane, so that a waterborne polyurethane coating has a good antifouling effect, and the coordination and unification of coating sterilization and anti-adhesion are realized.

In order to achieve the above object, the present invention provides the following technical solutions:

a bactericidal glycol chain extender has the structural formula:

the invention also aims to provide a preparation method of the bactericidal glycol chain extender, which comprises the following steps:

dissolving dibromooctapentanediol and 1, 2-benzisothiazole-3-ketone in a solvent, putting the solution into a microwave reactor, reacting for 2 to 12 hours at the temperature of between 20 and 60 ℃, and purifying to obtain a diol chain extender containing a bactericidal group; the mol ratio of the dibromooctanetetramethylene glycol to the 1, 2-benzisothiazole-3-ketone is 1.0 to 2.5.

The specific reaction route and the process are as follows:

compared with the prior art, the invention adopts dibromooctylpentanediol and 1, 2-benzisothiazol-3-one (BIT) to carry out chemical reaction in a microwave reactor, and then the diol chain extender containing the bactericidal group is prepared by purification. The prepared antifouling waterborne polyurethane can be widely applied to textiles, plastics, medical health and the like, particularly the field of marine antifouling; on the other hand, the method does not cause environmental pollution, can also reduce the production cost of products and save energy.

Preferably, the solvent is one or more of dichloromethane, dimethyl sulfoxide and methanol.

Preferably, the post-reaction purification step is: the reacted product was extracted with any one solvent of ethyl acetate, dichloromethane or chloroform, then dried with anhydrous magnesium sulfate or anhydrous sodium sulfate, filtered and rotary-evaporated to remove the solvent, and then dried at 45 ℃ for 8h under vacuum.

Preferably, the reaction temperature is 45 to 55 ℃.

The invention also aims to provide a preparation method of the multifunctional synergistic antifouling waterborne polyurethane, which comprises the following steps:

s1: mixing diisocyanate and vegetable oil-based polyol at 65-85 ℃, uniformly dispersing, adding a chain extender and a catalyst, and continuing to react for 10-30 min; the chain extender comprises the bactericidal diol chain extender and a conventional ionic chain extender;

s2: adding butanone or acetone for dilution, continuing to react for 30-150 min, cooling to room temperature after the reaction is finished, neutralizing by a neutralizing agent, adding water for emulsification, and removing the solvent (butanone or acetone) by rotary evaporation to obtain the multifunctional synergistic antifouling waterborne polyurethane emulsion.

In the preparation of polyurethanes, diisocyanates, catalysts, ionic chain extenders and neutralizing agents conventional in the art can be employed in the present invention, with the reaction conditions also being conventionally controlled.

Preferably, the molar ratio of the vegetable oil-based polyol to the diisocyanate to the chain extender is 1.0 to 1.8 to 2.6. Preferably, the solid content of the antifouling aqueous polyurethane emulsion is 5-50%.

Preferably, the vegetable oil-based polyol is one or a mixture of two of fluorine-containing vegetable oil-based polyol and silicone vegetable oil-based polyol;

the structural formula of the fluorine-containing vegetable oil-based polyol is shown in the specification

Wherein R is ₁ Is any one of alkyl, substituted alkyl or heteroalkyl, R' is any one of-O-, ester group, -N-or-NH-, and N is an integer of 3-7;

the structural formula of the organic silicon vegetable oil-based polyol is shown in the specification

Wherein R is methyl or ethyl, R ₁ Is one of alkyl, substituted alkyl or heteroalkyl, and R' is one of-O-, ester, -N-or-NH-.

Preferably, the solid content of the aqueous polyurethane emulsion is 5-50%; the solid content of the catalyst is 0.1-1% by total mass of diisocyanate and organic silicon vegetable oil-based polyol.

Preferably, the reaction temperature in the step S1 is 50-90 ℃, and the reaction time is 20-30 min; in the step S2, the reaction temperature is 70-80 ℃, and the reaction time is 60-90 min.

Compared with the prior art, the invention has the following beneficial effects:

(1) The multifunctional synergistic antifouling waterborne polyurethane quantitatively introduces bactericidal and anti-adhesion groups through covalent bonds, and reduces the release of antibacterial agents and the pollution to the surrounding environment.

(2) The organosilicon, fluorocarbon chain and bactericidal group in the multifunctional synergistic antifouling waterborne polyurethane have the migration property to the surface in the film forming process and the polyurethane side chain alkoxy is hydrolyzed and condensed to generate chemically bonded nano SiO in situ ₂ Constructing a super-hydrophobic nano topological structure with surface sterilization, fouling desorption and antifouling; meanwhile, an antifouling structure with different concentration gradients of Si, F and the bactericide from the surface layer to the bottom layer is obtained, and the coordination and unification of the sterilization and the adhesion resistance of the coating are realized.

(3) The main raw material of the waterborne polyurethane is renewable vegetable oil resource of natural source, a molecular chain is provided with a plurality of hydroxyl groups, and chemically bonded nano SiO is generated by combining with hydrolysis condensation reaction of alkoxy on a polyurethane side chain ₂ And a nano composite network cross-linked structure is formed, so that the mechanical property and the water resistance of the antifouling waterborne polyurethane can be effectively improved.

(4) Because the multifunctional synergistic antifouling waterborne polyurethane emulsion provided by the invention takes water as a dispersion medium, and the bactericidal groups are introduced into the coating through covalent bonds, compared with a release antifouling coating, the multifunctional synergistic antifouling waterborne polyurethane emulsion can effectively reduce the environmental toxicity, and can be widely applied to the fields of textiles, plastics, medical treatment and health, and particularly marine antifouling; on the other hand, the method does not cause environmental pollution, can also reduce the production cost of products and save energy.

(5) The main raw materials of the multifunctional synergistic antifouling waterborne polyurethane emulsion provided by the invention are green renewable vegetable oil resources instead of petrochemical products, so that the degradability and safety are improved, secondary pollution is not generated, and the problems of global fossil resource excessive consumption, energy and environment are favorably alleviated.

On the other hand, the invention also provides multifunctional synergistic antifouling waterborne polyurethane which is prepared by the preparation method.

In addition, the application of the multifunctional synergistic antifouling waterborne polyurethane in preparing waterborne polyurethane coating films, coatings, sealants, adhesives, foams or composite materials is also within the protection scope of the invention.

Drawings

FIG. 1 is a reaction scheme of the multifunctional synergistic antifouling waterborne polyurethane in examples 2 to 10

FIG. 2 is a particle size distribution diagram of the multifunctional synergistic antifouling aqueous polyurethane obtained in examples 2 to 10 and comparative examples 1 to 2;

FIG. 3 is a bar graph showing the water absorption of the multifunctional synergistic antifouling aqueous polyurethane coating films obtained in examples 2 to 10 and comparative examples 1 to 2;

FIG. 4 is a histogram showing the number of viable bacteria adhered to the surface of the multifunctional synergistic antifouling aqueous polyurethane coating film obtained in examples 2 to 10 and comparative examples 1 to 2;

FIG. 5 is a schematic diagram showing the contact sterilization effect of the multifunctional synergistic antifouling waterborne polyurethane obtained in examples 2 to 6 and comparative examples 1 to 2.

Detailed Description

The present invention is further illustrated by the following examples. It is to be understood that the following examples are illustrative of the present invention only and are not intended to limit the scope of the present invention. Experimental procedures without specific conditions noted in the examples below, generally according to conditions conventional in the art or as suggested by the manufacturer; the raw materials, reagents and the like used are, unless otherwise specified, those commercially available from the conventional markets and the like. Any insubstantial changes and substitutions made by those skilled in the art based on the present invention are intended to be covered by the claims.

The bactericidal diol chain extender, the multifunctional synergistic antifouling aqueous polyurethane emulsion or the aqueous polyurethane coating material provided by each embodiment are characterized as follows.

1) Hydrogen nuclear magnetic resonance spectroscopy the hydrogen nuclear magnetic resonance spectroscopy results of the diol chain extender containing a double bactericidal group obtained in example 1 are as follows: (400MHz, DMSO,. Delta.ppm): 3.13 (s, 4H), 3.34 (s, 4H), 4.43 (m, 2H), 7.21-7.53 (m, 6H), wherein, the H of 7.21-7.53ppm is the characteristic peak of hydrogen on the benzene ring.

2) In order to examine the bulk properties and antifouling properties of the multifunctional synergistic antifouling waterborne polyurethane emulsion prepared in example 1 (examples 2 to 10) and the coating, the following tests were carried out:

(1) Stability of aqueous polyurethane emulsion

Aqueous polyurethane emulsion stability characterized by centrifuging the sample at 3000rpm for 30min using a Tomos 3-18 centrifuge from Shanghai Tomo scientific instruments.

(2) Particle size distribution and Zeta potential

The particle size distribution and Zeta potential of the aqueous polyurethane emulsion were measured with a Zeta-sizer Nano ZSE from malvern instruments ltd, u.k. The sample was diluted to about 0.01% by weight before the test.

(3) Mechanical Properties

The measurement was carried out by using Shimadzu AGS-X Universal tensile tester, shimadzu corporation, shimadzu, japan. The testing speed is 100mmmin ^-1 . The sample specification was 25mm × 10mm (length × width). Each sample was tested for 6 replicates and averaged.

(4) Contact angle

Using the water drop shape analysis system DSA 100 (Kruss, hamburg, germany), 3. Mu.L of distilled water was used at room temperature. The test results are the average of three replicates after 10s exposure to water.

(5) Pencil hardness and adhesion: testing the polyurethane coating for pencil hardness and adhesion according to ASTM D3359 and ASTM D3363; the adhesion of the coating to the substrate was tested according to ASTM D4541-09.

(6) And (3) water resistance of the coating: the coating was cut into 10mm by 10mm squares, accurately weighed as W ₀ Soaking the membrane in deionized water at room temperature for 1-72 hr, taking out, drying with filter paper, and weighing (Wt). The water absorption of the polyurethane film is calculated according to the following formula: water absorption (%) = (Wt-W) ₀ )/W ₀ 。

(7) Test of antibacterial and antifouling Properties

The Minimum Inhibitory Concentration (MIC) test specifically includes that the bactericidal chain extender prepared in example 1, the antifouling aqueous polyurethane emulsions prepared in examples 2 to 10, and the antifouling aqueous polyurethane emulsions prepared in comparative examples 1 and 2 are subjected to a Minimum Inhibitory Concentration (MIC) test under the NCCLS standard method, and the results are shown in table 6.

Antibacterial adhesion test the aqueous non-toxic polyurethane emulsions obtained in comparative examples 1 and 2 and the aqueous non-toxic antibacterial polyurethane emulsions obtained in examples 2 to 10 were formed into films, which were then cut into 0.5X 0.5cm pieces and placed in 2ml 10 ⁷ CFU/ml of E.coli and S.aureus containing broth (nutrient broth NB) was incubated at 37 ℃ and 110rpm for 2 days, and the membrane-free broth was used as a blank. After two days, the membrane was taken out and washed with sterile water 3 times, then the bacteria adhered to the membrane were shaken off by ultrasonic waves, and the plate count was performed after gradient dilution, and the results are shown in fig. 4.

Contact sterilization performance: the polyurethane emulsion (50. Mu.l) obtained in examples 2-6 was directly coated on a glass slide to form a region of 1.5X 1.5cm in size, evaporated at room temperature for 24 hours, placed in a 60 ℃ oven for baking for 48 hours, then placed in a 60 ℃ vacuum oven for baking for 48 hours, and placed in a clean bench for UV sterilization for at least 4 hours. Then diluting to 10 ⁶ And (3) uniformly spraying the CFU/mL staphylococcus aureus liquid on the surface of the whole glass slide, placing the glass slide in sterile air for naturally drying for 10min, then placing the glass slide in a culture dish, slowly pouring 0.8% agar culture medium into the glass slide, and placing the glass slide in an incubator for inverted culture at 37 ℃ for 24h. The petri dish was removed, 3mL of a solution of 5mg/mL TTC in water was added, and the results were observed after half an hour of staining, and are shown in FIG. 5.

In the following examples, example 1 is a diol chain extender containing a bactericidal group and a preparation method thereof, and examples 2 to 10 are multifunctional synergistic antifouling waterborne polyurethane prepared by using example 1, diisocyanate, polyol (polyol I or polyol II or a mixture of polyol I and polyol II) and a conventional chain extender and a preparation method thereof; the polyol I is fluorine-containing plant oil-based antifouling polyol with a general structural formula

The polyol II is organic silicon vegetable oil-based antifouling polyol, and the structural general formula is as follows:

wherein R is methyl or ethyl, R ₁ Is one of alkyl, substituted alkyl, heteroalkyl and alkyl heterocyclic group, and R' is one of-O-, ester, -N-or-NH-.

Example 1:

this example provides a bactericidal diol chain extender, which uses dibromooctylpentanediol and 1, 2-benzisothiazol-3-one (BIT) to perform a chemical reaction in a microwave reactor, and the specific process is as follows.

Dibromooctylpentanediol and 1, 2-benzisothiazol-3-one (BIT) in a molar ratio of 1.0:2.4 adding the mixture into a reaction bottle, adding methanol for dissolving, placing the mixture into a microwave reactor, heating the mixture to 50 ℃ for constant temperature reaction for 12 hours, extracting the obtained product with ethyl acetate, drying the product with anhydrous magnesium sulfate, filtering and performing rotary evaporation to remove the ethyl acetate, and then drying the product overnight at 45 ℃ under vacuum to obtain the sterilizing glycol chain extender which is a nonionic antibacterial glycol chain extender.

Examples 2 to 6:

examples 2-6 provide a series of cationic multifunctional synergistic stain resistant waterborne polyurethanes prepared using the glycol chain extender prepared in example 1.

Specifically, the aqueous polyurethane emulsion is prepared by the following steps: polyols I and II and diisocyanate were each introduced into a two-necked flask with mechanical stirring and mixed with stirring at a temperature of 75 ℃ for 15 minutes (reaction stage 1). Then, the catalyst (0.5 mass% of the reactants) and the chain extender obtained in example 1 and MDEA were added to continue the reaction for 20 minutes (reaction stage 2). Then 30% solids Methyl Ethyl Ketone (MEK) was added to reduce the viscosity of the system and the reaction was continued for 60 minutes. Then, when the temperature was cooled to room temperature, the system was neutralized with acetic acid for about 15 minutes. Finally, the mixture was emulsified with distilled water at 600rpm for 60 minutes (emulsification time), and then excess MEK was removed by rotary evaporation to obtain an aqueous Polyurethane (PU). Table 2 shows the specific reaction conditions of the examples, and Table 3 shows the experimental ratios of the examples. The structures of polyol I and polyol II used in examples 2-6 are as follows:

the structural formula of the polyol I is as follows:

polyol II, organic silicon vegetable oil base polyol structural formula:

TABLE 2 examples 2-10 Experimental parameters for aqueous polyurethane emulsions

TABLE 3 examples 2-10 formulations of aqueous polyurethane emulsions

Note: a, hydroxyl molar equivalent of antifouling polyol; b, hydroxyl molar equivalent of the chain extender.

Examples 7 to 8:

examples 7-8 provide a series of anionic multifunctional synergistic antifouling waterborne polyurethanes prepared using example 1

Specifically, the aqueous polyurethane emulsion is prepared by the following steps: the polyols I and II and TDI, respectively, were charged into a two-necked flask equipped with mechanical stirring and mixed with stirring at a temperature of 60 ℃ for 30 minutes (reaction stage 1). Then, the reaction was continued for 15 to 30 minutes with the addition of the catalyst (0.5 mass% of reactants) and the chain extender obtained in example 1 and DMPA (reaction stage 2). Methyl Ethyl Ketone (MEK) was then added at 30% solids to reduce the viscosity of the system and the reaction was continued for 60 minutes. Then, when the temperature was cooled to room temperature, the system was neutralized with triethylamine for about 60 minutes. Finally, the mixture was emulsified with distilled water at 400rpm for 120 minutes (emulsification time), and then excess MEK was removed by rotary evaporation to obtain an aqueous Polyurethane (PU). Table 2 shows the specific reaction conditions of the examples, and Table 3 shows the experimental ratios of the examples. The structures of polyol I and polyol II used in examples 7 and 8 are as follows:

polyol I: fluorine-containing vegetable oil-based polyol:

polyol II, structural formula of organic silicon vegetable oil-based polyol:

examples 9 to 10:

examples 9-10 provide a series of anionic multifunctional synergistic antifouling waterborne polyurethanes prepared using example 1

Specifically, the aqueous polyurethane emulsion is prepared by the following steps: polyols i and ii and LDI were each charged to a two-necked flask equipped with mechanical stirring and mixed with stirring at a temperature of 90 ℃ for 10 minutes (reaction stage 1). Then, the catalyst (0.5% mass fraction of the reactants) and the chain extender obtained in example 1 were added and reacted with DMBA for 10 minutes (reaction stage 2). Methyl Ethyl Ketone (MEK) was then added at 30% solids to reduce the viscosity of the system and the reaction was continued for 30 minutes. Then, when the temperature was cooled to room temperature, the system was neutralized with triethylamine for about 30 minutes. Finally, the mixture was emulsified with distilled water at a speed of 800rpm for 30 minutes (emulsification time), and then excess MEK was removed by rotary evaporation to obtain an aqueous Polyurethane (PU). Table 2 shows the specific reaction conditions of the examples, and Table 3 shows the experimental ratios of the examples. The polyol I and polyol II used in examples 9-10 have the following structures:

polyol I: fluorine-containing vegetable oil-based polyol:

polyol II, structural formula of organic silicon vegetable oil-based polyol:

comparative example 1

The cationic waterborne polyurethane emulsion is prepared by taking common vegetable oil without organic silicon and fluorocarbon chains as polyol and not containing the bactericidal glycol chain extender prepared in example 1, and the specific preparation process is as follows.

The castor oil polyol and IPDI were added to a two-necked flask equipped with mechanical stirring and mixed with stirring at a temperature of 78 ℃ for 10 minutes. Then, DBTDL (1% mass fraction of polyol) was added to the mixture, followed by reaction for 10 to 30 minutes. After a subsequent addition of MDEA chain extension reaction for 30min, 40wt.% butanone was added to reduce the viscosity of the system. The reaction was then continued for 2h and the system was neutralized with TEA and stirred for about 30 min. Wherein the molar ratio of OH (polyol): NCO: OH (chain extender) is 1:2:0.9, finally adding water to emulsify for 2 hours at a speed of 600rpm, and then removing excess MEK by rotary evaporation to obtain an aqueous polyurethane emulsion having a solid content of 15%.

Comparative example 2

This comparative example provides a cationic antifouling aqueous polyurethane that does not contain the germicidal diol chain extender of example 1, but contains a silicone vegetable oil-based polyol and a fluorine-containing vegetable oil-based polyol.

Specifically, the aqueous polyurethane emulsion is prepared by the following steps: the polyols I and II and IPDI were each introduced into a two-necked flask with mechanical stirring and mixed with stirring at a temperature of 75 ℃ for 15 minutes (reaction stage 1). Then, the catalyst (0.5% mass fraction of reactants) and MDEA were added and the reaction was continued for 20 minutes (reaction stage 2). Methyl Ethyl Ketone (MEK) was then added at 30% solids to reduce the viscosity of the system and the reaction was continued for 60 minutes. Then, when the temperature was cooled to room temperature, the system was neutralized with acetic acid for about 15 minutes. Finally, the mixture was emulsified with distilled water at 600rpm for 60 minutes (emulsification time), and then excess MEK was removed by rotary evaporation to obtain an aqueous Polyurethane (PU). Wherein OH (polyol I) OH (polyol II): NCO (IPDI): OH (chain extender) molar ratio 0.5:0.5:2:0.9, comparative example 2 with polyol I and polyol ii the structures are as follows:

the structural formula of the polyol I is as follows:

polyol II, organic silicon vegetable oil base polyol structural formula:

and (4) testing and analyzing results:

the aqueous polyurethane emulsions obtained in examples 2 to 10 and comparative examples 1 to 2 were poured into a silica gel mold and dried at room temperature to obtain films for further analysis. All samples were dried at 60 ℃ for more than 12h prior to testing.

Table 4 particle diameter, zeta potential and storage stability of the aqueous polyurethane emulsions obtained in examples 2 to 10 and comparative example

Sample(s)	Particle size (nm)	Zeta potential (mV)	Storage stability (moon)
				Example 2	1028.9±1.7	32.7±3.1	＞24
Example 3	927.1±4.8	33.1±2.4	＞24
				Example 4	843.8±3.2	38.5±6.2	＞24
Example 5	746.9±5.7	39.3±4.1	＞24
				Example 6	489.2±4.1	45.8±2.7	＞24
Example 7	849.6±8.4	-38.5±5.3	＞24
				Example 8	695.4±1.8	-42.6±3.1	＞24
Example 9	563.4±4.2	-47.2±2.3	＞24
				Example 10	297.4±2.4	-47.9±4.9	＞24
Comparative example 1	60.3±1.9	37.4±1.5	＞24
				Comparative example 2	229.63±2.6	35.1±1.1	＞24

As can be seen from Table 4, the particle diameters of the antifouling aqueous polyurethane emulsions obtained in examples 2 to 6 are 489.2 to 1028.9nm, which are higher than those of comparative example 1 (60.3 nm), indicating that the hydrophilicity of the aqueous polyurethane is reduced by introducing the silicone vegetable oil-based polyol and the fluorine-containing vegetable oil-based polyol. Meanwhile, as the content of the nonionic antibacterial glycol chain extender prepared in the embodiment 1 in the components is reduced and the content of the hydrophilic chain extender MDEA is increased, the particle size of the aqueous polyurethane emulsion obtained in the embodiments 2 to 6 is gradually reduced, because as the content of the hydrophilic chain extender is increased, the proportion of the hydrophilic component in the neutralized polyurethane structure is gradually increased, the overall hydrophilicity of the polyurethane is increased, and the particle size of the emulsion is gradually reduced.

Pouring the polyurethane emulsion obtained in the embodiment into a polytetrafluoroethylene or silicified glass mold, standing at room temperature for moisture volatilization, and drying in a common oven at 60 ℃ for 2 days after the surface of the film is dried and does not stick to hands, so as to obtain the antifouling plant oil-based waterborne polyurethane coating film for testing contact angle and antifouling performance. The contact angle results are shown in table 5. We can see that the water contact angle (121.0-142.2 ℃) of the water-based polyurethane coating film prepared by the organic silicon polyol is far higher than that (62.3 ℃) of a comparative example without silicon, and the introduction of organic silicon and fluorocarbon chains greatly improves the hydrophobicity of the coating film, so that the antifouling property of the coating film is facilitated. The reason is that in the film forming process, the organosilicon with low surface energy and the fluorocarbon chains migrate to a gas-liquid interface (namely the surface of the coating film), so that a large number of hydrophobic organosilicon structures are accumulated on the surface of the coating film, the hydrophobicity of the coating film is improved, and the attachment of fouling substances such as microorganisms on the coating film is favorably prevented. And the introduction of the nonionic antibacterial glycol chain extender obtained in the embodiment 1 has little influence on the hydrophilic and hydrophobic properties of the surface of the antifouling coating, and does not influence the anti-adhesion property of the coating.

The tensile strength, elongation at break, pencil hardness, adhesion and the like of the antifouling aqueous coating films obtained in examples 2 to 10 were shown in table 5. The result shows that the tensile strength of the coating is enhanced and the hardness of the coating is higher by introducing the nonionic antibacterial glycol chain extender obtained in example 1, which is probably because the nonionic antibacterial glycol chain extender obtained in example 1 contains two rigid benzene ring structures, and the mechanical property of the coating is improved after the nonionic antibacterial glycol chain extender is introduced into the coating.

Next, we characterized the water resistance of the antifouling aqueous coating films obtained in examples 2 to 10, and the results are shown in FIG. 3. The water absorption of the aqueous polyurethane emulsion coatings obtained in examples 2 to 6 is gradually increased along with the decrease of the content of the nonionic antibacterial glycol chain extender obtained in example 1 and the increase of the content of the hydrophilic chain extender MDEA, because the proportion of the hydrophilic component of the polyurethane structure after neutralization is gradually increased along with the increase of the content of the hydrophilic chain extender, the overall hydrophilicity of the polyurethane is increased, and the water absorption is increased. The test results of the contact angle and the water absorption rate show that the multifunctional synergistic antifouling waterborne polyurethane obtained in the embodiments 2-10 has good water resistance.

TABLE 5 mechanical properties, adhesion and contact angle of antifouling aqueous polyurethane coatings obtained in examples 2-10 and comparative examples

Pencil hardness (6B-HB-6H, 6H = hardest), adhesion (5B = best)

TABLE 6 minimum inhibitory concentration test (MIC)

As can be seen from the data in Table 6, when the content of the nonionic antibacterial glycol chain extender obtained in example 1 in the aqueous polyurethane emulsion is increased, the MIC thereof is gradually reduced, and the antifouling aqueous polyurethane emulsion of the present invention is endowed with a good antibacterial effect. The antifouling property of the coating films of the waterborne polyurethanes obtained in examples 2 to 10 was characterized by a table shaking method, and comparative examples 1 and 2 were used as controls. The results of the experiment are shown in FIG. 4, and the antifouling effect of the coating film on Staphylococcus aureus and Escherichia coli was obtained by plate counting. Both the bacteria can adhere to the surface of the polyurethane coating obtained in comparative example 1 without the bactericidal and anti-adhesion components at a high adhesion rate, after the organosilicon polyol and the fluorocarbon chain are introduced, the number of adhesion bacteria on the surface of the polyurethane film is obviously reduced, and the anti-adhesion rate exceeds 90% (comparative example 2), while after the nonionic antibacterial glycol chain extender obtained in example 1 is introduced, the number of viable bacteria on the surface of the coating is gradually reduced along with the increase of the content of the chain extender, so that the viable bacteria are hardly observed, and the anti-bacterial adhesion performance can reach 99.99% at most (figure 4). The introduction of the low surface energy organosilicon antifouling polyol and the fluorocarbon chain polyol can effectively improve the anti-bacterial adhesion capability of the polyurethane film, while the introduction of the nonionic antibacterial diol chain extender obtained in the example 1 can kill bacteria attached to the coating, achieve a higher antibacterial effect, and realize the synergistic antifouling of the waterborne polyurethane coating.

In order to characterize the influence of the introduction of the nonionic antibacterial diol chain extender obtained in example 1 on the antibacterial and antifouling performance of the coating, the invention directly coats the obtained antifouling aqueous polyurethane emulsion obtained in examples 2-6 on a glass slide to form a film (1.5 × 1.5 cm) and tests the contact bactericidal performance of the film, and the result is shown in fig. 5, wherein comparative example 1 does not contain the nonionic antibacterial diol chain extender obtained in example 1, and a large number of bacterial colonies are uniformly distributed on the surface of the coating and around the coating and do not have the bactericidal performance at all; comparative example 2 although the introduction of organosilicon fluorocarbon chains provided a coating with excellent antimicrobial adhesion ability (fig. 4), it did not have contact sterilization performance because the introduction of the nonionic antimicrobial glycol chain extender obtained in example 1 was omitted; on the other hand, if no bacterial colonies were observed on the surface of the aqueous polyurethane coating obtained by introducing the nonionic antibacterial diol chain extender obtained in example 1, the bactericidal effect was 99.99% or more. The method shows that the organosilicon, the fluorocarbon chain and the nonionic antibacterial glycol chain extender are simultaneously introduced, so that the waterborne polyurethane can be endowed with good antibacterial and anti-adhesion capabilities, and the coordination and unification of antibacterial and anti-adhesion are realized.

It should be finally noted that the above examples are only intended to illustrate the technical solutions of the present invention, and not to limit the scope of the present invention, and that other variations and modifications based on the above description and thought may be made by those skilled in the art, and that all embodiments need not be exhaustive. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A preparation method of a sterilization type glycol chain extender is characterized by comprising the following steps: dissolving dibromooctylpentanediol and 1, 2-benzisothiazole-3-ketone in a solvent, putting the solvent into a microwave reactor, reacting for 2-12 h at 20-60 ℃, and purifying to obtain the sterilization type glycol chain extender containing a sterilization group; the mol ratio of the dibromooctanetetramethylene glycol to the 1, 2-benzisothiazole-3-ketone is 1.0 to 2.5;

the structural formula of the sterilization type glycol chain extender is as follows:

2. the method according to claim 1, wherein the solvent is one or more of dichloromethane, dimethyl sulfoxide, and methanol.

3. The method of claim 1, wherein the post-reaction purification step is: the reacted product was extracted with any one solvent of ethyl acetate, dichloromethane or chloroform, then dried with anhydrous magnesium sulfate or anhydrous sodium sulfate, filtered and rotary-evaporated to remove the solvent, and then dried at 45 ℃ for 8h under vacuum.

4. The preparation method of the multifunctional synergistic antifouling waterborne polyurethane is characterized by comprising the following steps:

s1: mixing diisocyanate and vegetable oil-based polyol at 65-85 ℃, uniformly dispersing, adding a chain extender and a catalyst, and continuously reacting for 10-30 min; the chain extender comprises the bactericidal glycol chain extender prepared by the preparation method of claim 1 and a conventional ionic chain extender; the vegetable oil-based polyol is one or a mixture of a fluorine-containing vegetable oil-based polyol and an organosilicon vegetable oil-based polyol;

s2: adding butanone or acetone for dilution, continuing to react for 30-150 min, cooling to room temperature after the reaction is finished, neutralizing by a neutralizer, adding water for emulsification, and removing the solvent by rotary evaporation to obtain the multifunctional synergistic antifouling waterborne polyurethane emulsion.

5. The production method according to claim 4, wherein the molar ratio of the vegetable oil-based polyol to the diisocyanate to the chain extender is 1.0 to 1.8 and 2.6.

6. The production method according to claim 4,

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Wherein R is ₁ Is any one of alkylene, substituted alkylene or heteroalkylene, R' is any one of-O-, ester group or-NH-, and n is an integer of 3-7;

Wherein R is methyl or ethyl, R ₁ Is one of alkylene, substituted alkylene or heteroalkylene, and R' is one of-O-, ester or-NH-.

7. The preparation method according to claim 4, wherein the solid content of the aqueous polyurethane emulsion is 5-50%; the solid content of the catalyst is 0.1-1% by total mass of diisocyanate and organic silicon vegetable oil-based polyol.

8. The method according to claim 4, wherein the reaction temperature in step S2 is 70 to 80 ℃ and the reaction time is 60 to 90min.

9. A multifunctional synergistic antifouling waterborne polyurethane is characterized in that: prepared by the preparation method of any one of claims 4 to 8.