阅读说明：本技术 聚硫密封胶硫化用高活性δ型花状二氧化锰及其制备方法 (High-activity flower-shaped manganese dioxide for polysulfide sealant vulcanization and preparation method thereof ) 是由 牛和林 吴笛 郭俊涛 廉笑 于 2020-06-05 设计创作，主要内容包括：本发明公开了一种聚硫密封胶硫化用高活性δ型花状二氧化锰及其制备方法。采用球形碳酸锰作为前驱物模板,使用高锰酸钾为氧化剂,添加少量金属盐后在反应釜中通过高温水热反应数个小时,得到花状δ型二氧化锰。本发明中的花状δ型二氧化锰用于聚硫密封胶的硫化时,硫化速率是市售二氧化锰的3倍,且具有更好的力学性能。此外,这种制备方法很少有废气、废液、废渣产生,污染极低。(The invention discloses high-activity flower-shaped manganese dioxide for polysulfide sealant vulcanization and a preparation method thereof. Spherical manganese carbonate is adopted as a precursor template, potassium permanganate is adopted as an oxidant, and after a small amount of metal salt is added, the flower-shaped manganese dioxide is obtained by a high-temperature hydrothermal reaction in a reaction kettle for a plurality of hours. When the flower-shaped manganese dioxide is used for vulcanizing polysulfide sealant, the vulcanization rate is 3 times of that of the commercially available manganese dioxide, and the flower-shaped manganese dioxide has better mechanical property. In addition, the preparation method generates less waste gas, waste liquid and waste residue, and has extremely low pollution.)

1. A preparation method of high-activity flower-shaped manganese dioxide for polysulfide sealant vulcanization is characterized in that spherical manganese carbonate is adopted as a precursor template, potassium permanganate is adopted as an oxidant, a small amount of metal salt is added, and then the flower-shaped manganese dioxide is obtained through high-temperature hydrothermal reaction for a plurality of hours in a reaction kettle.

2. The preparation method of claim 1, wherein potassium permanganate, manganese carbonate and a small amount of metal salt are weighed according to a proportion, transferred to a polytetrafluoroethylene reaction kettle, added with a proper amount of water, the reaction kettle is placed in an oven, the temperature is kept between 60 ℃ and 180 ℃, after reaction for 4h to 18h, cooled to room temperature, the obtained precipitate is subjected to suction filtration to obtain a black manganese dioxide solid filter cake and a clear filtrate, the filter cake is washed with water for multiple times, placed in the oven, and dried at 60 ℃ to obtain black manganese dioxide powder; putting the manganese dioxide powder into a ball mill, adding a small amount of silane coupling agent, and ball-milling to obtain the high-activity flower-shaped manganese dioxide.

3. The preparation method according to claim 1, wherein the ratio of the amounts of the potassium permanganate and the manganese carbonate is 1: 0.8-1: 3.

4. The preparation method of claim 1, wherein the metal salt is one or more of sodium silicate, sodium chloride, sodium metaaluminate, calcium carbonate, magnesium carbonate, sodium chloride, ferric chloride, zinc sulfate, cobalt nitrate and nickel chloride.

5. The method according to claim 1, wherein the metal salt is added in an amount of 1 to 4 wt% based on the total mass of the raw materials.

6. The process according to claim 1, wherein the silane coupling agent is one or more selected from the group consisting of KH-550, KH-560, KH-570, KH-580, KH-590, KH-902, KH-903, KH-792, DL-602, A-150, A-151, A-171, A-172, A-1100, A-187, A-174, A-1891, A-189, and A-1120.

7. The method according to claim 1, wherein the silane coupling agent is added in an amount of 0.2 to 2 wt% based on the mass of the manganese dioxide powder.

8. The high-activity flower-shaped manganese dioxide for vulcanizing polysulfide sealant prepared by the preparation method of any one of claims 1-7 is flower-shaped manganese dioxide.

Technical Field

The invention relates to the field of inorganic chemical materials, in particular to high-activity flower-shaped manganese dioxide for vulcanizing polysulfide sealant and a preparation method thereof.

Background

The polysulfide sealant is the most common sealing material on an airplane, the common polysulfide sealant is two components, the component A is base paste, and the component B is a vulcanizing agent. The vulcanizing agent most commonly used today is activated manganese dioxide. The domestic production process of manganese dioxide for polysulfide sealing mainly comprises the step of carrying out liquid-phase reaction on potassium permanganate and soluble manganous salt. However, this method produces toxic gases and acidic waste liquid, and even if soda ash is used, the treatment effect is poor, the cost is high, the energy consumption is high, and the pollution is serious. And the manganese dioxide produced by the method is beta-type manganese dioxide, and the vulcanization efficiency is low when the manganese dioxide is used for vulcanizing polysulfide sealant. The vulcanization process of polysulfide rubber requires that the active period (i.e. the construction period) is large in the total vulcanization time, and the faster the total vulcanization rate is, the better.

Disclosure of Invention

The invention provides high-activity manganese dioxide for polysulfide sealant vulcanization and a preparation method thereof aiming at the defects of the prior art.

The invention adopts the following technical scheme:

a preparation method of high-activity flower-shaped manganese dioxide for polysulfide sealant vulcanization adopts spherical manganese carbonate as a precursor template, potassium permanganate as an oxidant, and a small amount of metal salt is added to perform high-temperature hydrothermal reaction in a reaction kettle for a plurality of hours to obtain the flower-shaped manganese dioxide.

The preparation method comprises the steps of weighing potassium permanganate, manganese carbonate and a small amount of metal salt according to a proportion, transferring the potassium permanganate, the manganese carbonate and the small amount of metal salt into a polytetrafluoroethylene reaction kettle, adding a proper amount of water, placing the reaction kettle into a drying oven, keeping the temperature between 60 ℃ and 180 ℃, cooling to room temperature after reacting for 4h to 18h, carrying out suction filtration on obtained precipitates to obtain a black manganese dioxide solid filter cake and clear filtrate, washing the filter cake for multiple times, placing the filter cake into the drying oven, and drying at 60 ℃ to obtain black manganese dioxide powder; putting the manganese dioxide powder into a ball mill, adding a small amount of silane coupling agent, and ball-milling to obtain the high-activity flower-shaped manganese dioxide.

According to the preparation method, the mass ratio of the potassium permanganate to the manganese carbonate is 1: 0.8-1: 3.

In the preparation method, the metal salt is one or more of sodium silicate, sodium chloride, sodium metaaluminate, calcium carbonate, magnesium carbonate, sodium chloride, ferric chloride, zinc sulfate, cobalt nitrate and nickel chloride.

In the preparation method, the addition amount of the metal salt is 1-4 wt% of the total mass of the raw materials.

The preparation method is characterized in that the silane coupling agent is one or a mixture of more of KH-550, KH-560, KH-570, KH-580, KH-590, KH-902, KH-903, KH-792, DL-602, A-150, A-151, A-171, A-172, A-1100, A-187, A-174, A-1891, A-189 and A-1120.

In the preparation method, the adding amount of the silane coupling agent is 0.2-2 wt% of the mass of the manganese dioxide powder.

The high-activity flower-shaped manganese dioxide for vulcanizing the polysulfide sealant prepared by any preparation method is flower-shaped manganese dioxide.

The invention has the following advantages:

1. spherical manganese carbonate is used as a template agent and reacts with potassium permanganate to obtain spherical manganese dioxide, because the spherical manganese carbonate is insoluble in water and has slow nucleation when reacting with potassium permanganate to generate manganese dioxide, and potassium ions in potassium permanganate can be fully embedded into a tunnel of the manganese dioxide to play a supporting role so as to generate the spherical manganese dioxide. However, spherical manganese dioxide is easy to agglomerate, the activity of the spherical manganese dioxide can be influenced, and the morphology of the manganese dioxide can be regulated and controlled by adding a certain amount of special metal cations. The manganese dioxide prepared by the invention is flower-shaped manganese dioxide, is not easy to agglomerate, solves the problem and has better sulfuration performance.

2. MnO formed₂Is flower-shaped, is not easy to agglomerate, and has a vulcanization rate 3 times that of a commercial product.

3. The preparation method generates less waste gas, waste liquid and waste residue, and has extremely low pollution.

Drawings

FIG. 1 is a Scanning Electron Micrograph (SEM) of spheric manganese carbonate;

FIG. 2 is an X-ray diffraction pattern (XRD) of manganese dioxide prepared in example 1;

FIG. 3 is a Scanning Electron Micrograph (SEM) of manganese dioxide prepared according to example 1;

FIG. 4 is an X-ray diffraction pattern (XRD) of manganese dioxide prepared in example 2;

FIG. 5 is a Scanning Electron Micrograph (SEM) of manganese dioxide prepared according to example 2;

FIG. 6 is an X-ray diffraction pattern (XRD) of manganese dioxide prepared in example 3;

FIG. 7 is a Scanning Electron Micrograph (SEM) of manganese dioxide prepared according to example 3;

Detailed Description

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