CN113480905A - Leather coating with fluorescent response to benzene-series VOCs and preparation method thereof - Google Patents

Abstract

The invention discloses a leather coating with fluorescence responsiveness to benzene-series VOCs (volatile organic compounds) and a preparation method thereof. The leather sample coated by the leather finishing agent with fluorescence responsiveness to the benzene-series VOCs prepared by the invention has fluorescence performance and fluorescence responsiveness, and the tensile strength, the tear strength and the bursting strength of the coated leather sample are respectively improved by 70%, 30.2% and 74.23%.

Description

Leather coating with fluorescent response to benzene-series VOCs and preparation method thereof

Technical Field

The invention belongs to the field of preparation of leather finishing agents, and particularly relates to a leather coating with fluorescent response to benzene-series VOCs and a preparation method thereof.

Background

Modern people live over 87% of their life and work in indoor spaces, and indoor air pollution is severe, and the main pollutants are Volatile Organic Compounds (VOCs), wherein benzene-based VOCs have been identified as strong carcinogens by the world health organization, and are therefore of great importance for the detection of indoor pollutants. Among the available detection methods, fluorescence detection technology is one of the most promising methods because of its advantages such as sensitivity and easy signal reading. Metal-organic Frameworks (MOFs) refer to crystalline materials with periodic network structures formed by self-assembly of small molecule organic ligands and metal ions or metal clusters. The zeolite molecular sieve not only has a crystal structure similar to that of a zeolite molecular sieve, but also can obtain pore canals and holes with different sizes through the directional design of a topological structure and the expansion of organic functional groups, and has unique properties of light, electricity, magnetism and the like.

The polyacrylate is one of the most widely applied film forming materials in leather finishing, and has the following main characteristics: excellent bending resistance, good dry and wet wiping performance, excellent light resistance and aging resistance, and good compatibility with other materials such as resin, pigment paste, wiping paste, casein and the like. But the polyacrylate is compact in film forming, and a compact film is formed on the surface of the leather after the polyacrylate is coated, so that a channel for diffusing water vapor molecules of a human body to the outside is blocked, the sanitary performance is reduced, and the wearing comfort of leather products is further influenced. In addition, the polyacrylate finishing agent has the defects of hot sticking, cold brittleness, organic solvent intolerance and the like, and further application of the polyacrylate finishing agent is limited. Therefore, researchers have made a lot of work on how to improve the comprehensive performance of polyacrylate coatings, mainly including compounding porous materials with polyacrylate emulsions and modifying polyacrylate by using protein film-forming materials with good hygienic properties.

Disclosure of Invention

The invention aims to provide a leather coating with fluorescent responsiveness to benzene-series VOCs and a preparation method thereof, and a leather sample coated by the composite leather finishing agent prepared by the method responds to the benzene-series VOCs.

In order to achieve the purpose, the invention provides the following technical scheme:

a preparation method of a leather coating with fluorescence responsiveness to benzene-series VOCs comprises the steps of firstly preparing a fluorescent organic ligand, preparing an MOFs material with fluorescence performance from the fluorescent organic ligand, other ligands and metal ions by a solvothermal method, and then introducing the MOFs material into a polyacrylate emulsion by a physical blending method to obtain the leather coating with fluorescence responsiveness to the benzene-series VOCs.

The method specifically comprises the following steps:

step one, preparation of organic ligand:

(1) preparation of 1,1,2, 2-tetrakis (4-bromophenyl) ethylene (intermediate):

dissolving tetraphenylethylene TPE in dichloromethane CH₂Cl₂In the stirring process, bromine water is dropwise added for four times, and after the dropwise addition is finished, the mixture is stirred at room temperature overnight. The product was extracted with a saturated solution of sodium bicarbonate and dichloromethane, the lower organic phase and the upper inorganic phase, the lower solution was taken off and the upper solution was extracted five more times with dichloromethane until the lower solution became clear. The combined organic phase solutions were rotary evaporated under reduced pressure to give white crystalline powder. Continuously using normal hexane for passing the powder through a column, and finally collecting white crystal powder;

(2) preparation of 1,1,2, 2-tetrakis (4-carboxystyrene):

transferring 1,1,2, 2-tetra (4-bromophenyl) ethylene and tetrahydrofuran into a three-neck flask, introducing nitrogen gas, dissolving under stirring, adjusting the temperature to-78 ℃ by adopting an acetone dry-ice bath after dissolution, stirring for 20 min to uniformly disperse the temperature of the system, adding n-butyllithium, dropwise adding for four times, and slowly adding. Stirring for 2 h at low temperature after the dropwise addition is finished, adding dry ice for stirring, removing the low-temperature bath after the reaction is finished, and stirring for 24 h at room temperature. And extracting the product with ethyl acetate, taking the supernatant, and continuously extracting the lower layer with ethyl acetate until the supernatant is colorless and transparent. Combining the supernatant, performing reduced pressure rotary evaporation, allowing the residual small amount of liquid to pass through a column by using normal hexane, and performing reduced pressure rotary evaporation to collect light yellow powder;

step two, preparing fluorescent metal organic framework compound materials MOFs:

respectively weighing 1,1,2, 2-tetra (4-carboxylphenyl) ethylene, 2-sulfoterephthalic acid and ZrCl with required mass₄Dissolving in N, N-dimethyl formamidePerforming ultrasonic treatment in DMF for 10 min; transferring the mixed solution into a reaction kettle, reacting for 24 hours at 120 ℃, and taking out; after centrifugation, a pale yellow solid was recovered and stirred in DMF for 24 h. Filtering to recover solid, stirring in methanol for 24 hr, filtering the suspension, filtering and washing to obtain product, and air drying;

step three, preparing the leather coating with fluorescent response to the benzene-series VOCs:

firstly, ultrasonically dispersing the MOFs material prepared in the step one in deionized water to obtain a suspension of the MOFs material, then adding the suspension into a polyacrylate emulsion, stirring and blending to obtain the polyacrylate/MOFs composite leather finishing agent.

In the step (1) of the first step, the using amount of TPE is 3-7 g; CH (CH)₂Cl₂The dosage of the composition is 50 mL-100 mL; the amount of the bromine water is 2-9 mL; the reaction time is 20-28 h.

In the step (2) of the first step, the dosage of 1,1,2, 2-tetra (4-bromostyrene) is 3-5 g; the dosage of the tetrahydrofuran is 90 mL-150 mL; the dosage of the n-butyl lithium is 1-5 mL; the dosage of the dry ice is 10-30 g.

In the second step, the ratio of 2-sulfoterephthalic acid to 1,1,2, 2-tetra (4-carboxystyrene) ethylene is 1: 0.8-1: 1.6.

In the third step, the ultrasonic dispersion time is 10-20 min; the using amount of the deionized water is 50 percent of the mass of the polyacrylate emulsion; the solid content of the polyacrylate emulsion was 42%; the dosage of the MOFs material is 0.05-3% of the solid content of the polyacrylate emulsion.

In the third step, the blending temperature of the suspension of the MOFs material and the polyacrylate emulsion is 50-85 ℃, the stirring speed is 300 r/min, and the blending time is 4-8 h.

The leather coating with fluorescent response to the benzene series VOCs prepared by the preparation method.

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

the fluorescent MOFs material is prepared from tetraphenylethylene TPE with aggregation-induced emission effect, and the organic phase of the MOFs material is favorable for uniform dispersion in a polyacrylate leather finishing agent due to the organic-inorganic composite material, so that the polyacrylate film is endowed with fluorescence property. Compared with a pure polyacrylate leather finishing agent, the leather sample coated by the leather finishing agent with fluorescence response to the benzene-series VOCs prepared by the invention has fluorescence performance and fluorescence response performance. In addition, tensile strength, tear strength and burst strength of the finished leather were increased by 70%, 30.2% and 74.23%, respectively.

Drawings

FIG. 1 is a fluorescence spectrum of MOFs materials and a fluorescence response spectrum of benzene-series VOCs;

FIG. 2 is a fluorescence spectrum of the composite film and a fluorescence response spectrum of benzene-based VOCs.

Detailed Description

The present invention will be described in further detail with reference to specific examples, but the embodiments of the present invention include, but are not limited to, the scope shown in the following examples.

Example 1

(1) Preparation of 1,1,2, 2-tetrakis (4-bromophenyl) ethylene (intermediate)

3 g of TPE dissolved in 50 mL of CH₂Cl₂3 g of bromine water is dropwise added in the stirring process, the dropwise addition is carried out for four times, and the stirring is carried out overnight at room temperature after the dropwise addition is finished. The product was extracted with a saturated solution of sodium bicarbonate and dichloromethane, the lower organic phase and the upper inorganic phase, the lower solution was taken off and the upper solution was extracted five more times with dichloromethane until the lower solution became clear. The combined organic phase solutions were rotary evaporated under reduced pressure to give white crystalline powder. The powder was further subjected to column chromatography with n-hexane to finally collect white crystalline powder. Weighing 4 g of 1,1,2, 2-tetra (4-bromophenyl) ethylene and tetrahydrofuran, transferring into a three-neck flask, introducing nitrogen gas, dissolving under stirring, adjusting the temperature to-78 ℃ by adopting an acetone dry ice bath after dissolution, stirring for 20 min to uniformly disperse the temperature of the system, adding 2 mL of n-butyllithium, dropwise adding for four times, and slowly adding. Stirring for 2 h at low temperature after the dropwise addition is finished, adding 20 g of dry ice, stirring, removing the low-temperature bath after the reaction is finished, and stirring for 24 h at room temperature. Extracting the product with ethyl acetate, and collecting the extractThe supernatant and the lower layer are continuously extracted by ethyl acetate until the supernatant is colorless and transparent. And combining the supernatant liquid, performing reduced pressure rotary evaporation, allowing the residual small amount of liquid to pass through a column by adopting n-hexane, and performing reduced pressure rotary evaporation to collect light yellow powder.

(2) Preparation of fluorescent Metal Organic Framework (MOFs):

1,1,2, 2-tetrakis (4-carboxylphenyl) ethylene and 2-sulphoterephthalic acid in a ratio of 1:0.8 and 2 g of ZrCl₄Dissolving in 30 mL of N, N-Dimethylformamide (DMF), and performing ultrasonic treatment for 10 min; transferring the mixed solution into a reaction kettle, reacting for 24 hours at 120 ℃, and taking out; after centrifugation, a pale yellow solid was recovered and stirred in DMF for 24 h. The solid was recovered by filtration, stirred in methanol for 24 h, the suspension filtered off again, washed by filtration and the product dried in air.

(3) Preparation of leather coating with fluorescent response to benzene-series VOCs

Firstly, dispersing the MOFs material prepared in the step one in deionized water by ultrasonic wave for 10 min to obtain a suspension of the MOFs material, then adding the suspension into a polyacrylate emulsion, stirring and blending to obtain the polyacrylate/MOFs composite leather finishing agent. Wherein the mass of the deionized water is 50% of that of the polyacrylate emulsion, the solid content of the polyacrylate emulsion is 33%, and the dosage of the MOFs material is 3% of that of the polyacrylate emulsion.

Example 2

(1) Preparation of 1,1,2, 2-tetrakis (4-bromophenyl) ethylene (intermediate)

4 g of TPE dissolved in 70 mL of CH₂Cl₂During the stirring, 5 g of bromine water was added dropwise in four times, and after completion of the addition, the mixture was stirred at room temperature overnight. The product was extracted with a saturated solution of sodium bicarbonate and dichloromethane, the lower organic phase and the upper inorganic phase, the lower solution was taken off and the upper solution was extracted five more times with dichloromethane until the lower solution became clear. The combined organic phase solutions were rotary evaporated under reduced pressure to give white crystalline powder. The powder was further subjected to column chromatography with n-hexane to finally collect white crystalline powder. 5 g of 1,1,2, 2-tetra (4-bromophenyl) ethylene and tetrahydrofuran are weighed and transferred into a three-port furnaceAnd (3) introducing nitrogen into the bottle, dissolving the mixture under stirring, then adopting an acetone dry ice bath to reduce the temperature to-78 ℃, stirring the mixture for 20 min to uniformly disperse the temperature of the system, adding 5 mL of n-butyl lithium, dropwise adding the n-butyl lithium for four times, and slowly adding the n-butyl lithium. Stirring for 2 h at low temperature after the dropwise addition is finished, adding 25 g of dry ice, stirring, removing the low-temperature bath after the reaction is finished, and stirring for 24 h at room temperature. And extracting the product with ethyl acetate, taking the supernatant, and continuously extracting the lower layer with ethyl acetate until the supernatant is colorless and transparent. And combining the supernatant liquid, performing reduced pressure rotary evaporation, allowing the residual small amount of liquid to pass through a column by adopting n-hexane, and performing reduced pressure rotary evaporation to collect light yellow powder.

(2) Preparation of fluorescent Metal Organic Framework (MOFs):

ZrCl prepared from 1,1,2, 2-tetra (4-carboxystyrene) ethylene and 2-sulfoterephthalic acid in a ratio of 1:1 and 2 g₄Dissolving in 35 mL of N, N-Dimethylformamide (DMF), and performing ultrasonic treatment for 10 min; transferring the mixed solution into a reaction kettle, reacting for 24 hours at 120 ℃, and taking out; after centrifugation, a pale yellow solid was recovered and stirred in DMF for 24 h. The solid was recovered by filtration, stirred in methanol for 24 h, the suspension filtered off again, washed by filtration and the product dried in air.

(3) Preparation of leather coating with fluorescent response to benzene-series VOCs

Firstly, dispersing the MOFs material prepared in the step one in deionized water by ultrasonic wave for 10 min to obtain a suspension of the MOFs material, then adding the suspension into a polyacrylate emulsion, stirring and blending to obtain the polyacrylate/MOFs composite leather finishing agent. Wherein the mass of the deionized water is 50% of that of the polyacrylate emulsion, the solid content of the polyacrylate emulsion is 33%, and the dosage of the MOFs material is 10% of that of the polyacrylate emulsion.

Example 3

(1) Preparation of 1,1,2, 2-tetrakis (4-bromophenyl) ethylene (intermediate)

5 g of TPE dissolved in 100 mL of CH₂Cl₂During the stirring, 7.5 g of bromine water was added dropwise in four times, and after completion of the addition, the mixture was stirred at room temperature overnight. The product was taken up in a saturated solution of sodium bicarbonate andextracting with dichloromethane, wherein the lower layer is an organic phase, the upper layer is an inorganic phase, taking the lower layer solution, and continuously extracting the upper layer solution with dichloromethane five times until the lower layer solution is transparent. The combined organic phase solutions were rotary evaporated under reduced pressure to give white crystalline powder. The powder was further subjected to column chromatography with n-hexane to finally collect white crystalline powder. Weighing 5 g of 1,1,2, 2-tetra (4-bromophenyl) ethylene and tetrahydrofuran, transferring the mixture into a three-neck flask, introducing nitrogen gas, dissolving the mixture under stirring, bringing the temperature to-78 ℃ by adopting an acetone dry ice bath after the dissolution is finished, stirring the mixture for 20 min to ensure that the temperature of the system is uniformly dispersed, adding 2 mL of n-butyllithium, dropwise adding the n-butyllithium for four times, and slowly adding the n-butyllithium. Stirring for 2 h at low temperature after the dropwise addition is finished, adding 30 g of dry ice, stirring, removing the low-temperature bath after the reaction is finished, and stirring for 24 h at room temperature. And extracting the product with ethyl acetate, taking the supernatant, and continuously extracting the lower layer with ethyl acetate until the supernatant is colorless and transparent. And combining the supernatant liquid, performing reduced pressure rotary evaporation, allowing the residual small amount of liquid to pass through a column by adopting n-hexane, and performing reduced pressure rotary evaporation to collect light yellow powder.

(2) Preparation of fluorescent Metal Organic Framework (MOFs):

1,1,2, 2-tetrakis (4-carboxylphenyl) ethylene and 2-sulphoterephthalic acid in a ratio of 1:2 and 2 g of ZrCl₄Dissolving in 40 mL of N, N-Dimethylformamide (DMF), and performing ultrasonic treatment for 10 min; transferring the mixed solution into a reaction kettle, reacting for 24 hours at 120 ℃, and taking out; after centrifugation, a pale yellow solid was recovered and stirred in DMF for 24 h. The solid was recovered by filtration, stirred in methanol for 24 h, the suspension filtered off again, washed by filtration and the product dried in air.

(3) Preparation of leather coating with fluorescent response to benzene-series VOCs

Firstly, dispersing the MOFs material prepared in the step one in deionized water by ultrasonic wave for 10 min to obtain a suspension of the MOFs material, then adding the suspension into a polyacrylate emulsion, stirring and blending to obtain the polyacrylate/MOFs composite leather finishing agent. Wherein the mass of the deionized water is 50% of that of the polyacrylate emulsion, the solid content of the polyacrylate emulsion is 33%, and the dosage of the MOFs material is 15% of that of the polyacrylate emulsion.

FIG. 1 is a fluorescence spectrum of MOFs materials and a fluorescence response spectrum of benzene-series VOCs.

The figure shows the fluorescence response performance of MOFs materials to different benzene series VOCs, and illustrates that the MOFs materials can generate different fluorescence changes when contacting different benzene series VOCs, and the response of the MOFs materials to the benzene series VOCs is reflected.

FIG. 2 is a fluorescence spectrum of the composite film and a fluorescence response spectrum of benzene-based VOCs.

The figure shows the fluorescent response performance of the MOFs/polyacrylate composite film to different benzene-series VOCs, and shows that the MOFs/polyacrylate composite film can generate different fluorescent changes when contacting different benzene-series VOCs, and shows that the MOFs material still has fluorescent response to the benzene-series VOCs after being compounded.

The invention is not limited to the examples, and any equivalent changes to the technical solution of the invention by a person skilled in the art after reading the description of the invention are covered by the claims of the invention.

Claims (8)

1. A preparation method of a leather coating with fluorescent response to benzene series VOCs is characterized by comprising the following steps:

firstly, preparing a fluorescent organic ligand, preparing the MOFs material with the fluorescent property by the fluorescent organic ligand, other ligands and metal ions through a solvothermal method, and then introducing the MOFs material into a polyacrylate emulsion through a physical blending method to obtain the leather coating with the fluorescent response to the benzene-series VOCs.

2. The method for preparing the leather coating with fluorescence responsiveness to benzene-based VOCs according to claim 1, wherein the method comprises the following steps:

the method specifically comprises the following steps:

step one, preparation of organic ligand:

(1) preparation of 1,1,2, 2-tetrakis (4-bromophenyl) ethylene (intermediate):

dissolving tetraphenylethylene TPE in dichloromethane CH₂Cl₂In stirringDropwise adding bromine water in the stirring process for four times, and stirring overnight at room temperature after dropwise adding; extracting the product with saturated solution of sodium bicarbonate and dichloromethane, wherein the lower layer is an organic phase and the upper layer is an inorganic phase, taking the lower layer solution, and continuously extracting the upper layer solution with dichloromethane for five times until the lower layer solution is transparent; combining the organic phase solutions, and performing reduced pressure rotary evaporation to obtain white crystal powder; continuously using normal hexane for passing the powder through a column, and finally collecting white crystal powder;

(2) preparation of 1,1,2, 2-tetrakis (4-carboxystyrene):

transferring 1,1,2, 2-tetra (4-bromophenyl) ethylene and tetrahydrofuran into a three-neck flask, introducing nitrogen gas, dissolving under stirring, adjusting the temperature to-78 ℃ by adopting an acetone dry-ice bath after dissolution, stirring for 20 min to uniformly disperse the temperature of the system, adding n-butyllithium, dropwise adding for four times, and slowly adding; stirring for 2 hours at low temperature after the dropwise addition is finished, adding dry ice for stirring, removing a low-temperature bath after the reaction is finished, and stirring for 24 hours at room temperature; extracting the product with ethyl acetate, taking the supernatant, and continuously extracting the lower layer with ethyl acetate until the supernatant is colorless and transparent; combining the supernatant, performing reduced pressure rotary evaporation, allowing the residual small amount of liquid to pass through a column by using normal hexane, and performing reduced pressure rotary evaporation to collect light yellow powder;

step two, preparing fluorescent metal organic framework compound materials MOFs:

respectively weighing 1,1,2, 2-tetra (4-carboxylphenyl) ethylene, 2-sulfoterephthalic acid and ZrCl with required mass₄Dissolving in a certain amount of N, N-dimethylformamide DMF, and performing ultrasonic treatment for 10 min; transferring the mixed solution into a reaction kettle, reacting for 24 hours at 120 ℃, and taking out; centrifuging, recovering a light yellow solid, and stirring in DMF for 24 h; filtering to recover solid, stirring in methanol for 24 hr, filtering the suspension, filtering and washing to obtain product, and air drying;

step three, preparing the leather coating with fluorescent response to the benzene-series VOCs:

firstly, ultrasonically dispersing the MOFs material prepared in the step one in deionized water to obtain a suspension of the MOFs material, then adding the suspension into a polyacrylate emulsion, stirring and blending to obtain the leather coating with fluorescent response to the benzene-series VOCs.

3. The method for preparing the leather coating with fluorescence responsiveness to benzene-based VOCs according to claim 2, wherein the method comprises the following steps:

in the step (1) of the first step, the using amount of TPE is 3-7 g; CH (CH)₂Cl₂The dosage of the composition is 50 mL-100 mL; the amount of the bromine water is 2-9 mL; the reaction time is 20-28 h.

4. The method for preparing the leather coating with fluorescence responsiveness to benzene-based VOCs according to claim 3, wherein the method comprises the following steps:

in the step (2) of the first step, the dosage of 1,1,2, 2-tetra (4-bromostyrene) is 3-5 g; the dosage of the tetrahydrofuran is 90 mL-150 mL; the dosage of the n-butyl lithium is 1-5 mL; the dosage of the dry ice is 10-30 g.

5. The method for preparing the leather coating with fluorescence responsiveness to benzene-based VOCs according to claim 2, wherein the method comprises the following steps:

in the second step, the ratio of 2-sulfoterephthalic acid to 1,1,2, 2-tetra (4-carboxystyrene) ethylene is 1: 0.8-1: 1.6.

6. The method for preparing the leather coating with fluorescence responsiveness to benzene-based VOCs according to claim 2, wherein the method comprises the following steps:

in the third step, the ultrasonic dispersion time is 10-20 min; the using amount of the deionized water is 50 percent of the mass of the polyacrylate emulsion; the solid content of the polyacrylate emulsion was 42%; the dosage of the MOFs material is 0.05-3% of the solid content of the polyacrylate emulsion.

7. The method for preparing the leather coating with fluorescence responsiveness to benzene-based VOCs according to claim 2, wherein the method comprises the following steps:

in the third step, the blending temperature of the suspension of the MOFs material and the polyacrylate emulsion is 50-85 ℃, the stirring speed is 300 r/min, and the blending time is 4-8 h.

8. The method of claim 1, wherein the fluorescent leather coating comprises VOCs.

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