阅读说明：本技术 一种乙醇铝的制备方法 (Preparation method of aluminum ethoxide ) 是由 刘眠 盛磊 刘静 于 2020-06-28 设计创作，主要内容包括：本发明涉及金属有机物的制备领域,更具体地,涉及一种乙醇铝的合成方法。本发明的方法包括如下步骤：将低熔点金属与铝制成铝基合金,将所述铝基合金与乙醇直接进行反应得乙醇铝；所述低熔点金属为镓、铟、锌、锡、镁或铋中的一种或几种。本发明利用铝基合金与无水乙醇常温直接制取乙醇铝,工艺简便、环境友好,低熔点合金可以反复利用,使生产成本大幅降低。(The invention relates to the field of preparation of metal organic matters, and in particular relates to a synthetic method of aluminum ethoxide. The method of the invention comprises the following steps: preparing aluminum-based alloy from low-melting-point metal and aluminum, and directly reacting the aluminum-based alloy with ethanol to obtain aluminum ethoxide; the low-melting-point metal is one or more of gallium, indium, zinc, tin, magnesium or bismuth. The method directly prepares the aluminum ethoxide by using the aluminum-based alloy and the absolute ethyl alcohol at normal temperature, has simple and convenient process and environmental protection, can repeatedly utilize the low-melting-point alloy, and greatly reduces the production cost.)

1. The method for synthesizing the aluminum ethoxide is characterized by comprising the following steps of: preparing aluminum-based alloy from low-melting-point metal and aluminum, and directly reacting the aluminum-based alloy with ethanol to obtain aluminum ethoxide; the low-melting-point metal is one or more of gallium, indium, zinc, tin, magnesium or bismuth.

2. The synthesis method according to claim 1, characterized in that the aluminium-based alloy is in the state of a metallic powder.

3. A synthesis method according to claim 1 or 2, characterized in that the aluminium-based alloy is prepared by a method comprising the steps of mixing one or more of gallium, indium, zinc, tin, magnesium or bismuth with aluminium and ball milling in vacuum or argon atmosphere.

4. The synthesis method according to claim 1 or 2, wherein the mass percent of aluminum in the aluminum-based alloy is 50-95%.

5. The synthesis method according to claim 1 or 4, characterized in that the low-melting metal is gallium, indium, a mixture of zinc and tin, a mixture of gallium and indium, a mixture of tin and bismuth or a mixture of zinc and magnesium;

preferably, the low-melting-point metal is a mixture of gallium, indium, zinc and tin, and the addition amount of the low-melting-point metal is 12% of gallium, 5% of indium, 2% of zinc and 1% of tin;

or the low-melting-point metal is a mixture of gallium, indium, zinc and tin, and the addition amount of the low-melting-point metal is 10% of gallium, 4% of indium, 4% of zinc and 2% of tin;

or, the low-melting point metal is a mixture of gallium and indium, and the addition amount of the low-melting point metal is 6% of gallium and 4% of indium;

or the low-melting-point metal is a mixture of tin and bismuth, and the addition amount of the low-melting-point metal is 20% of tin and 10% of bismuth;

or the low-melting-point metal is a mixture of zinc and magnesium, the addition amount of the low-melting-point metal is 10 percent of zinc and 10 percent of magnesium.

6. The method of synthesis according to claim 1, wherein the ethanol has a water content of less than 1%.

7. The synthesis method according to claim 1 or 6, wherein the mass ratio of the aluminum-based alloy to the ethanol is 1: 10-30.

8. The synthesis method according to claim 1, wherein the synthesis of aluminum ethoxide is carried out in a vacuum reaction kettle.

9. The synthesis method according to claim 1 or 8, wherein the aluminum ethoxide in the system is extracted by xylene after the reaction is completed to obtain an aluminum ethoxide primary product, and the xylene in the aluminum ethoxide primary product is removed to obtain the aluminum ethoxide.

10. The synthesis method according to claim 9, wherein the xylene removal is carried out by heating the primary product of aluminum ethoxide at 130-150 ℃.

Technical Field

The invention relates to the field of preparation of metal organic matters, and in particular relates to a synthetic method of aluminum ethoxide.

Background

Aluminum ethoxide is an important chemical formula: al (C)₂H₅O)₃It can be used as reducing agent for reducing carbonyl compound into alcohol, catalyst for esterification reaction and polymerization reaction, organic synthesis condensing agent, ethanol dehydrating agent, and production of fine alumina.

The laboratory often uses anhydrous ethanol to react with aluminum amalgam to produce aluminum ethoxide. The reaction process requires heating at reflux for 24h or more. Meanwhile, the preparation method is complex and pollutes the environment.

Chinese patent CN1483511 uses anhydrous aluminum trichloride as a catalyst and ethyl acetate as a solvent, aluminum scraps, aluminum trichloride and ethyl acetate are added into a reaction kettle, heating and refluxing are carried out for 20-60 minutes, the prepared mixed solution of ethanol and ethyl acetate is slowly dripped into the reaction kettle within 2-8 hours, reaction is continued for 2-10 hours, and the mixed solution is cooled to room temperature, so that an ethyl acetate solution of aluminum ethoxide is obtained. However, the method still has the defects of long time consumption, complex operation process and the like.

Chinese patent CN 108358759A is that one or more of tin, bismuth, gallium, indium and zinc and aluminum are melted into uniform liquid phase by a high-frequency induction power supply in gas atomization powder preparation equipment, the melting power is increased before atomization, the magnetic stirring effect is enhanced, high-pressure inert gas is used for spraying atomization and cooling to obtain Al-N type alloy powder, and the Al-N type alloy powder and ethanol are used for preparing aluminum ethoxide at normal temperature.

Disclosure of Invention

Technical problem to be solved

In order to solve the problems of environmental pollution, long time consumption, complex operation and the like in the process of preparing the aluminum ethoxide in the prior art, the invention provides a simple method for synthesizing the aluminum ethoxide.

(II) technical scheme

The method comprises the following steps: preparing aluminum-based alloy from low-melting-point metal and aluminum, and directly reacting the aluminum-based alloy with ethanol to obtain aluminum ethoxide; the low-melting-point metal is one or more of gallium, indium, zinc, tin, magnesium or bismuth.

The invention utilizes low-melting-point metal and aluminum to prepare aluminum-based alloy, and continuously inhibits the formation of an oxide film on the surface of the aluminum under the catalysis of the low-melting-point metal in the process of preparing the alloy. Meanwhile, the activation energy of the reaction is greatly reduced by using low-melting-point metal, so that aluminum and absolute ethyl alcohol directly react to generate aluminum ethoxide.

Preferably, the aluminum-based alloy is a metal powder. The alloy is prepared into powder, so that the alloy is beneficial to the full contact and reaction with ethanol.

Preferably, the aluminum-based alloy is prepared by mixing one or more of gallium, indium, zinc, tin or bismuth with aluminum and performing ball milling treatment in vacuum or argon atmosphere. The ball milling process is adopted, so that the smelting process for preparing the alloy can be avoided, and the process is simple and convenient. Secondly, the ball milling can enable the low-melting-point alloy and the aluminum to be mixed more fully, an oxide film on the surface of the aluminum is abraded, the activation performance of the alloy is better compared with a pulverization process after smelting, and the contact starting time with ethanol is shorter.

Preferably, the mass percent of aluminum in the aluminum-based alloy is 50-95%. If the mass percentage of aluminum is less than 50%, the yield of aluminum ethoxide may be reduced, and if it is more than 95%, the catalytic performance of the low melting metal may be significantly reduced, so that the content of aluminum may be controlled within the above range.

Preferably, the low melting point metal is gallium, indium, a mixture of zinc and tin, a mixture of gallium and indium, a mixture of tin and bismuth, or a mixture of zinc and magnesium;

preferably, the low-melting-point metal is a mixture of gallium, indium, zinc and tin, and the addition amount of the low-melting-point metal is 12% of gallium, 5% of indium, 2% of zinc and 1% of tin;

or the low-melting-point metal is a mixture of gallium, indium, zinc and tin, and the addition amount of the low-melting-point metal is 10% of gallium, 4% of indium, 4% of zinc and 2% of tin;

or, the low-melting point metal is a mixture of gallium and indium, and the addition amount of the low-melting point metal is 6% of gallium and 4% of indium;

or the low-melting-point metal is a mixture of tin and bismuth, and the addition amount of the low-melting-point metal is 20% of tin and 10% of bismuth;

or the low-melting-point metal is a mixture of zinc and magnesium, the addition amount of the low-melting-point metal is 10 percent of zinc and 10 percent of magnesium.

The percentage is the percentage of each metal in the total mass of the aluminum-based alloy, and the balance is filled with aluminum.

Preferably, the water content in the ethanol is less than 1%. The aluminum ethoxide reacts with water to generate aluminum hydroxide, so that the yield is reduced, impurities are introduced, and the smaller the water content of the ethanol is, the better the water content is.

As a preferred mode of operation, the ethanol is dehydrated by multiple refluxing with quicklime.

Preferably, the mass ratio of the aluminum-based alloy to the ethanol is 1: 10-30. The molar ratio of the aluminum alloy ethanol reaction is 1:3, the mass ratio is about 1:6, and the proper excessive ethanol is added to make up for the volatilization loss of the ethanol in the defense process and ensure the quick start of the reaction.

Preferably, the synthesis of the aluminum ethoxide is carried out in a vacuum reaction kettle.

Preferably, after the reaction is finished, extracting aluminum ethoxide in the system through xylene to obtain an aluminum ethoxide primary product, and removing the xylene in the aluminum ethoxide primary product to obtain the aluminum ethoxide. Other metals only act as activators in the reaction process, rarely participate in the reaction, still exist in the form of metal simple substances or alloys after the reaction, can be effectively separated by extracting the aluminum ethoxide with the xylene, and the residual metals can be recycled.

Preferably, the specific operation of removing the xylene is to heat the primary product of the aluminum ethoxide at 130-150 ℃.

The invention has the following beneficial effects:

1) the method has the advantages of simple operation, short time consumption, no environmental pollution, reaction at normal temperature and no technical difficulty.

2) The invention has low reaction cost, the low melting point metal used for catalysis can be used repeatedly, the recovered metal exists in the form of metal simple substance or alloy, and can be smelted into the form of alloy by cleaning, and then the metal is added into aluminum for ball milling again, thus achieving the same effect.

3) The aluminum ethoxide prepared by the method has high generation rate and few impurities.

4) The aluminum complexing agent is simple and convenient to prepare and convenient for industrial production.

Drawings

FIG. 1 is a flow chart of the process described in example 1.

Detailed Description

The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.