CN107345261B - Eight carboxyl silsesquioxane tanning agent of water solubility and its method based on the preparation of mercaptan-alkene clicking chemistry method - Google Patents

Abstract

The present invention relates to the eight carboxyl silsesquioxane tanning agents of water solubility and its method that are prepared based on mercaptan-alkene clicking chemistry method, eight vinyl silsesquioxane of cage modle is prepared for using vinyltrimethoxysilane by hydrolytic condensation method first, then under photoinitiator and ultraviolet lamp irradiation condition, it reacts with thioacetic acid to get water-soluble eight carboxyl silsesquioxane tanning agents.Yield of the present invention is high, purity is high, the easily controllable operation of reaction process, and the reaction time is short；And the tanning agent has certain tanning effect, and 2% chromium powder is cooperated to be applied to goat acid skin process for tanning, the shrinkage temperature of crust leather promotes 35 DEG C after tanning, thickens rate up to 67% or so.

Description

Water-soluble octacarboxysilsesquioxane tanning based on thiol-ene click chemistry agent and method

technical field

The invention relates to the technical field of leather tanning agent synthesis, in particular to a water-soluble octacarboxysilsesquioxane tanning agent prepared based on a thiol-ene click chemistry method and a method thereof.

Background technique

With the improvement of people's living standards, leather products have gradually become an indispensable necessity in today's life. Hundreds of leather chemicals are used in leather processing. These materials are essential to obtain leather with excellent performance. Among them, tanning agents can chemically interact with rawhide collagen fibers to transform rawhide into leather and make leather. It is a chemical material with flexibility, high strength, water resistance, heat resistance, corrosion resistance and chemical stability. At present, the tanning agents used in leather making are mainly chrome tanning agents. The comprehensive performance of chrome tanning agents for tanning leather is unmatched by other inorganic tanning agents, synthetic tanning agents and vegetable tanning agents. But in recent years, with the increasing environmental problems of chrome tanning and the strategic consideration of chrome resources, chrome tanning agents and chrome tanning methods have faced severe challenges. At present, tanners have begun to focus on the research of chrome-free or less chrome tanning agents to meet the needs of the environment and ensure the sustainable development of the leather industry.

Polyhedral oligomeric silsesquioxane (POSS) is a new type of organic-inorganic nanoparticles with a relatively high proportion of silicon and oxygen in recent years. It was first synthesized in 1946 by DW et al. The general molecular formula is (RSO _1.5 ) _n , and n is generally 6, 8, 10, 12, etc., of which n=8 is the most typical. POSS is considered to be the morphologically stable and smallest silicon nanoparticle, with a diameter of about 1 nm. POSS has a hollow rigid cage structure, and has become a research hotspot due to its immobilized molecular structure and easy-to-modify surface. A number of different functional groups can be introduced on the surface of POSS, such as vinyl, hydroxyl, methacryloyloxy, alkoxy, epoxy, amino, etc., to make it have different functional or reactive functional nanometers particle.

Click chemistry is the American chemist Sharpless [Kolb H C, FinnM G, Sharpless K B. Click chemistry: diverse chemical function from a few good reactions[J]. Angewandte Chemie International Edition, 2001, 40(11 ):2004-2021] proposed a new method for the rapid synthesis of a large number of compounds. This kind of reaction raw materials and reagents are easily available, widely used, simple and mild reaction conditions, almost unaffected by external environment, no heavy metal catalysts, high yield, easy separation and purification of products, no need for solvents or easy separation of solvents used. . Thiol-ene click chemistry is a new type of click chemistry developed in recent years. It uses photo-initiated radical reaction as a catalytic medium, and fully combines the advantages of photo-initiated process with the characteristics of traditional click reactions. Reactions between specific regions and functional groups with high selectivity have become an important way to synthesize materials.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a water-soluble octacarboxysilsesquioxane tanning agent prepared based on a thiol-ene click chemical method and a method thereof. The use of the tanning agent can improve the thermal stability and filling property of leather, and can also Reduce the use of chromium powder in the tanning process, and reduce the content of Cr ³⁺ in the waste liquor after tanning.

The technical scheme adopted in the present invention is:

A method for preparing a water-soluble octacarboxysilsesquioxane tanning agent based on a thiol-ene click chemistry method, characterized in that:

This is achieved by the following steps:

Step 1: Synthesis of cage octavinylsilsesquioxane:

Add 33-66mL of vinyltrimethoxysilane to a 1000mL three-necked flask, then add 337-675mL of acetone, place in a water bath equipped with a condensing and heating stirrer, add 97-125mL, 6mol/L of dilute hydrochloric acid Slowly add it dropwise to the flask and stir at 30-45°C under reflux;

After the reaction, the product is washed and dried to obtain a white powdery cage octavinyl silsesquioxane;

Then use sufficient amount of dichloromethane to dissolve cage octavinyl silsesquioxane, and wait for the solvent to volatilize to form a homogeneous saturated solution to crystallize a white solid;

Step 2: Preparation of water-soluble octacarboxysilsesquioxane:

The cage-type octavinyl silsesquioxane obtained in step 1 and thioglycolic acid are dissolved in a sufficient amount of dichloromethane in a molar ratio of 1:(8-10);

Then add cage-type octavinyl silsesquioxane and 1%-2% by mass of thioglycolic acid, the photoinitiator benzoin dimethyl ether, put it in a conical flask, and then irradiate it under an ultraviolet lamp. Pale yellow viscous liquid;

The liquid is washed 2-3 times with distilled water, the solution is layered after fully standing, and there is a white product at the boundary between the water phase and the oil phase;

The mixture of the product and distilled water is heated on a constant temperature stirrer, and the volatilization system of dichloromethane is milky white. After the solvent is completely volatilized, it is left to stand, filtered, and dried naturally in a petri dish to obtain a colorless, transparent and viscous liquid. Water-soluble octacarboxysilsesquioxane tanning agent.

In step one:

The washing steps are: washing the product with 66-132mL absolute ethanol for 1-3 times;

The drying steps are: drying in a vacuum drying oven at 45-55 °C.

In the second step, the irradiation condition under the ultraviolet lamp is λ=365nm, and the time is 5-20min.

Water-soluble octacarboxysilsesquioxane tanning agent prepared by the method described.

The present invention has the following advantages:

The invention utilizes thiol-ene click chemistry to prepare the octacarboxyl cage-type silsesquioxane tanning agent. The method has the advantages of wide application range, simple reaction conditions, high speed and high yield, and is especially suitable for leather tanning agent synthesis technology. The field has important reference value. The tanning agent is a nano-hybrid material formed by covalent bonding. It has good water solubility. When it is tanned with 2% chrome powder, the shrinkage temperature of the tanned leather can be increased by 35°C, and the thickening rate can reach 67%. %about.

Detailed ways

The present invention will be described in detail below with reference to specific embodiments.

The water-soluble octacarboxysilsesquioxane tanning agent prepared by the thiol-ene click chemistry method and the method thereof involved in the invention firstly prepare the cage-type octavinyl silsesquioxane by the hydrolysis condensation method, and then prepare the octavinyl silsesquioxane in the light Under the condition of the initiator and UV lamp irradiation, react with thioglycolic acid to obtain a water-soluble octacarboxysilsesquioxane tanning agent. The reaction route is shown in the following figure:

The invention adopts the thiol-ene click chemistry method to prepare the water-soluble octacarboxysilsesquioxane tanning agent. Combination, so as to play the role of tanning; at the same time, the carboxyl group can be tanned with a small amount of chrome powder to achieve chrome-free or less chrome tanning, reduce leather pollution, and achieve cleaner production.

The specific steps are:

Step 1: Synthesis of cage octavinylsilsesquioxane:

Add 33-66mL of vinyltrimethoxysilane to a 1000mL three-necked flask, then add 337-675mL of acetone, place in a water bath equipped with a condensing and heating stirrer, add 97-125mL, 6mol/L of dilute hydrochloric acid Slowly add it dropwise to the flask and stir at 30-45°C under reflux;

After the reaction, the product is washed and dried to obtain a white powdery cage octavinyl silsesquioxane;

Then use sufficient amount of dichloromethane to dissolve cage octavinyl silsesquioxane, and wait for the solvent to volatilize to form a homogeneous saturated solution to crystallize a white solid;

Step 2: Preparation of water-soluble octacarboxysilsesquioxane:

The cage-type octavinyl silsesquioxane obtained in step 1 and thioglycolic acid are dissolved in a sufficient amount of dichloromethane in a molar ratio of 1:(8-10);

Then add cage-type octavinyl silsesquioxane and 1%-2% by mass of thioglycolic acid, the photoinitiator benzoin dimethyl ether, put it in a conical flask, and then irradiate it under a UV lamp. Pale yellow viscous liquid;

The liquid is washed 2-3 times with distilled water, the solution is layered after fully standing, and there is a white product at the boundary between the water phase and the oil phase;

The mixture of the product and distilled water is heated on a constant temperature stirrer, and the volatilization system of dichloromethane is milky white. After the solvent is completely volatilized, it is left to stand, filtered, and dried naturally in a petri dish to obtain a colorless, transparent and viscous liquid. Water-soluble octacarboxysilsesquioxane tanning agent.

In step one:

The washing steps are: washing the product with 66-132mL absolute ethanol for 1-3 times;

The drying steps are: drying in a vacuum drying oven at 45-55 °C.

In the second step, the irradiation condition under the ultraviolet lamp is λ=365nm, and the time is 5-20min.

Example 1:

At 35°C, 33 mL of vinyltrimethoxysilane was added to a 1000 mL three-necked flask, and then 337 mL of acetone was added, and placed in a water bath equipped with a condensing and heating stirrer. The diluted hydrochloric acid was slowly added dropwise to the flask, refluxed and stirred at 35 °C for 40 h. After the reaction, the product was washed three times with 66 mL of anhydrous ethanol, and then vacuum-dried at 45 °C for 48 h to obtain a white powder. Vinyl silsesquioxane; then dissolve the cage octavinyl silsesquioxane with an appropriate amount of dichloromethane, and wait for the solvent to volatilize for a certain period of time to form a homogeneous saturated solution and crystallize a white solid.

Weigh 0.2132g of cage-octavinylsilsesquioxane and 0.2764g of thioglycolic acid and dissolve them in dichloromethane to form a colorless, transparent and clear solution. Then, 0.0048 g of 1wt% photoinitiator benzoin dimethyl ether was added, placed in a conical flask, and irradiated under an ultraviolet lamp for 5 min. After the reaction, a pale yellow viscous liquid was obtained. The liquid was washed three times with distilled water, and the solution was layered after sufficiently standing, and a white product was found at the boundary between the water phase and the oil phase. The mixture of the product and distilled water is heated on a constant temperature stirrer, and the volatilization system of dichloromethane is milky white. After the solvent is completely volatilized, it is filtered after standing, and it is naturally evaporated in a petri dish to obtain a colorless, transparent and viscous eighth. Carboxysilsesquioxane.

Example 2:

At 45°C, 45 mL of vinyltrimethoxysilane was added to a 1000 mL three-necked flask, and then 337 mL of acetone was added, and placed in a water bath equipped with a condensing and heating stirrer. The diluted hydrochloric acid was slowly added dropwise to the flask, refluxed and stirred at 45 °C for 40 h. After the reaction, the product was washed three times with 66 mL of anhydrous ethanol, and then vacuum-dried at 45 °C for 48 h to obtain a white powder. Vinyl silsesquioxane; then dissolve the cage octavinyl silsesquioxane with an appropriate amount of dichloromethane, and wait for the solvent to volatilize for a certain period of time to form a homogeneous saturated solution and crystallize a white solid.

Weigh 0.2132g of vinylsilsesquioxane and 0.2764g of thioglycolic acid respectively and dissolve them in dichloromethane to form a colorless, transparent and clear solution. Then, 0.0048 g of 1wt% photoinitiator benzoin dimethyl ether was added, placed in a conical flask, and irradiated under an ultraviolet lamp for 5 min. After the reaction, a pale yellow viscous liquid was obtained. The liquid was washed three times with distilled water, and the solution was layered after sufficiently standing, and a white product was found at the boundary between the water phase and the oil phase. The mixture of the product and distilled water is heated on a constant temperature stirrer, and the volatilization system of dichloromethane is milky white. After the solvent is completely volatilized, it is filtered after standing, and dried naturally in a petri dish to obtain a colorless, transparent and viscous 8. Carboxysilsesquioxane.

Example 3:

At 40°C, 33 mL of vinyltrimethoxysilane was added to a 1000 mL three-necked flask, and then 337 mL of acetone was added, and placed in a water bath equipped with a condensing and heating stirrer. The diluted hydrochloric acid was slowly added dropwise to the flask, refluxed and stirred at 35 °C for 40 h. After the reaction, the product was washed three times with 66 mL of anhydrous ethanol, and then vacuum-dried at 45 °C for 48 h to obtain a white powder. Vinyl silsesquioxane; then dissolve the cage octavinyl silsesquioxane with an appropriate amount of dichloromethane, and wait for the solvent to volatilize for a certain period of time to form a homogeneous saturated solution and crystallize a white solid.

Weigh 0.2132g of cage-octavinylsilsesquioxane and 0.2764g of thioglycolic acid and dissolve them in dichloromethane to form a colorless, transparent and clear solution. Then, 0.0048 g of 1wt% photoinitiator benzoin dimethyl ether was added, placed in a conical flask, and irradiated under an ultraviolet lamp for 5 min. After the reaction, a pale yellow viscous liquid was obtained. The liquid was washed three times with distilled water, and the solution was layered after sufficiently standing, and a white product was found at the boundary between the water phase and the oil phase. The mixture of the product and distilled water is heated on a constant temperature stirrer, and the volatilization system of dichloromethane is milky white. After the solvent is completely volatilized, it is filtered after standing, and dried naturally in a petri dish to obtain a colorless, transparent and viscous 8. Carboxysilsesquioxane.

Example 4:

At 45°C, 66 mL of vinyltrimethoxysilane was added to a 1000 mL three-necked flask, and then 337 mL of acetone was added, and placed in a water bath equipped with a condensing and heating stirrer. The diluted hydrochloric acid was slowly added dropwise to the flask, refluxed and stirred at 45 °C for 40 h. After the reaction, the product was washed three times with 120 mL of anhydrous ethanol, and then vacuum-dried at 45 °C for 48 h.

A white powdery cage-type octavinyl silsesquioxane is obtained; then an appropriate amount of dichloromethane is used to dissolve the cage-type octavinyl silsesquioxane, and the white solid is crystallized after the solvent is volatilized for a certain period of time to form a homogeneous saturated solution.

Weigh 0.2132 g of cage octavinyl silsesquioxane and 0.1245 g of thioglycolic acid, respectively, and dissolve them in dichloromethane to form a colorless, transparent and clear solution. Then add 0.0048 g of 1wt% photoinitiator 2,2-dimethylolpropionic acid, place it in a conical flask, and irradiate it under a UV lamp for 5 min. After the reaction, a pale yellow viscous liquid was obtained. The liquid was washed three times with distilled water, and the solution was layered after sufficiently standing, and a white product was found at the boundary between the water phase and the oil phase. The mixture of the product and distilled water is heated on a constant temperature stirrer, and the volatilization system of dichloromethane is milky white. After the solvent is completely volatilized, it is filtered after standing, and it is naturally evaporated in a petri dish to obtain a colorless, transparent and viscous eighth. Carboxysilsesquioxane.

Example 5:

At 45°C, 66 mL of vinyltrimethoxysilane was added to a 1000 mL three-necked flask, and then 337 mL of acetone was added, and placed in a water bath equipped with a condensing and heating stirrer. The diluted hydrochloric acid was slowly added dropwise to the flask, refluxed and stirred at 45 °C for 40 h. After the reaction, the product was washed three times with 120 mL of anhydrous ethanol, and then vacuum-dried at 45 °C for 48 h.

A white powdery cage-type octavinyl silsesquioxane is obtained; then an appropriate amount of dichloromethane is used to dissolve the cage-type octavinyl silsesquioxane, and the white solid is crystallized after the solvent is volatilized for a certain period of time to form a homogeneous saturated solution.

Weigh 0.2132 g of cage octavinyl silsesquioxane and 0.1245 g of thioglycolic acid, respectively, and dissolve them in dichloromethane to form a colorless, transparent and clear solution. Then add 0.0068 g of 2wt% photoinitiator benzoin dimethyl ether, place it in a conical flask, and irradiate it under a UV lamp for 5 min. After the reaction, a pale yellow viscous liquid was obtained. The liquid was washed three times with distilled water, and the solution was layered after sufficiently standing, and a white product was found at the boundary between the water phase and the oil phase. The mixture of the product and distilled water is heated on a constant temperature stirrer, and the volatilization system of dichloromethane is milky white. After the solvent is completely volatilized, it is filtered after standing, and it is naturally evaporated in a petri dish to obtain a colorless, transparent and viscous eighth. Carboxysilsesquioxane.

The octacarboxysilsesquioxane tanning agent prepared by the invention is tanned with 2% chrome powder, which can increase the shrinkage temperature of the tanned leather by 35°C, and the thickening rate reaches about 67%.

The content of the present invention is not limited to those listed in the embodiments, and any equivalent transformations taken by those of ordinary skill in the art to the technical solutions of the present invention by reading the description of the present invention are covered by the claims of the present invention.

Claims (3)

1. the method for preparing water-soluble octacarboxysilsesquioxane tanning agent based on thiol-ene click chemistry, is characterized in that: This is achieved by the following steps: Step 1: Synthesis of cage octavinylsilsesquioxane: Add 33-66mL of vinyltrimethoxysilane to a 1000mL three-necked flask, then add 337-675mL of acetone, place in a water bath equipped with a condensing and heating stirrer, add 97-125mL, 6mol/L of dilute hydrochloric acid Slowly add it dropwise to the flask and stir at 30-45°C under reflux; After the reaction, the product is washed and dried to obtain a white powdery cage octavinyl silsesquioxane; Then use sufficient amount of dichloromethane to dissolve cage octavinyl silsesquioxane, and wait for the solvent to volatilize to form a homogeneous saturated solution to crystallize a white solid; Step 2: Preparation of water-soluble octacarboxysilsesquioxane: The cage-type octavinyl silsesquioxane obtained in step 1 and thioglycolic acid are dissolved in a sufficient amount of dichloromethane in a molar ratio of 1:(8-10); Then add cage-type octavinyl silsesquioxane and 1%-2% by mass of thioglycolic acid, the photoinitiator benzoin dimethyl ether, put it in a conical flask, and then irradiate it under a UV lamp. Pale yellow viscous liquid; The liquid is washed 2-3 times with distilled water, the solution is layered after fully standing, and there is a white product at the boundary between the water phase and the oil phase; The mixture of the product and distilled water is heated on a constant temperature stirrer, and the volatilization system of dichloromethane is milky white. After the solvent is completely volatilized, it is left to stand, filtered, and dried naturally in a petri dish to obtain a colorless, transparent and viscous liquid. Water-soluble octacarboxysilsesquioxane tanning agent; In step one: The washing steps are: washing the product with 66-132mL absolute ethanol for 1-3 times; The drying steps are: drying in a vacuum drying oven at 45-55 °C. 2. the method for preparing water-soluble octacarboxysilsesquioxane tanning agent based on thiol-ene click chemistry method according to claim 1, is characterized in that: In the second step, the irradiation condition under the ultraviolet lamp is λ=365nm, and the time is 5-20min. 3. The water-soluble octacarboxysilsesquioxane tanning agent obtained by the method of claim 1.