阅读说明：本技术 一种硼化型呋喃树脂的制备方法 (Preparation method of boronized furan resin ) 是由 刘萌 孙志勇 潘月宝 侯学臻 孙笃新 于 2020-06-30 设计创作，主要内容包括：本发明公开了一种硼化型呋喃树脂的制备方法,它属于呋喃树脂生产技术领域,以呋喃树脂为碳源,添加硼酸进行硼化,得到硼化型呋喃树脂,掺杂硼酸可以有效的提高呋喃树脂的石墨化度,从而提高了呋喃树脂的耐磨性能、热抗冲击性能及吸震性,且抗疲劳和抗蠕变、耐腐蚀、耐磨损性能也更好,热膨胀系数更小,使其具有更优异的耐高温性、很高的固化活性,且本发明通过改进原料及生产工艺,生产过程更加温和易控,不易凝胶固化,合成路线简洁、易操作,不需脱水,无废水产生。(The invention discloses a preparation method of boronized furan resin, which belongs to the technical field of furan resin production, wherein furan resin is used as a carbon source, boric acid is added for boronizing to obtain the boronized furan resin, and the boric acid is doped to effectively improve the graphitization degree of the furan resin, so that the wear resistance, thermal shock resistance and shock absorption of the furan resin are improved, the fatigue resistance, creep resistance, corrosion resistance and wear resistance are better, the thermal expansion coefficient is smaller, and the furan resin has more excellent high temperature resistance and higher curing activity.)

1. The preparation method of the boronized furan resin is characterized by comprising the following steps of:

(1) adding solid formaldehyde and part of furfuryl alcohol into a reaction kettle, stirring and mixing, adding boric acid, and adjusting the pH value to 4.5-6 by using benzoic acid;

(2) adding a catalyst of zinc acetate under the acidic condition, carrying out catalytic reaction at the temperature of 130-150 ℃, and keeping the temperature for 2 hours to obtain a polymer;

(3) adding the rest furfuryl alcohol, benzoic acid and maleic anhydride, adjusting the pH to 3.0-3.5, reacting at 130-135 ℃, and preserving the temperature for 2.5 hours;

(4) adding sodium hydroxide solution to adjust the pH value to 7-8, cooling, adding methanol, an aldehyde removing agent and a coupling agent, and stirring and mixing uniformly;

(5) adjusting the pH value to be neutral, continuously stirring and discharging to obtain the product.

2. The method for preparing boronized furan resin according to claim 1, wherein the raw materials in each reaction stage comprise, by weight: 15 parts of solid formaldehyde, 75-80 parts of furfuryl alcohol, 0.1-0.5 part of benzoic acid, 2-5 parts of boric acid, 0.2-0.5 part of maleic anhydride, 0.3 part of aldehyde removing agent, 3-5 parts of methanol and 0.4-0.8 part of coupling agent.

3. The method for preparing boronized furan resin according to claim 2, wherein the raw materials in each reaction stage comprise, by weight: 15 parts of solid formaldehyde, 76 parts of furfuryl alcohol, 0.1 part of benzoic acid, 5 parts of boric acid, 0.2 part of maleic anhydride, 0.3 part of aldehyde removing agent, 3 parts of methanol and 0.4 part of coupling agent.

4. The method for preparing a boronized furan resin of claim 1, wherein the furfuryl alcohol is added in a ratio of 1:1 in the steps (1) and (3).

5. The method for preparing boronized furan resin of claim 1, wherein the solid formaldehyde is paraformaldehyde with low degree of polymerization, and the content is 90.0-99.9%.

6. The method for preparing boronized furan resin of claim 1, wherein the coupling agent is N- (β -aminoethyl) - γ -aminopropylmethyldimethoxysilane.

7. The method for preparing boronized furan resin of claim 1, wherein said maleic anhydride is a 13% aqueous solution of maleic anhydride.

8. The method for preparing boronized furan resin of claim 1, wherein the concentration of said sodium hydroxide solution is 20-30%.

Technical Field

The invention relates to the technical field of furan resin production, and particularly relates to a preparation method of boronized furan resin.

Background

The furan resin has the characteristics of high normal temperature strength, good toughness and low toxicity, and the raw materials are easy to obtain and low in price, so that the furan resin is one of the resins with the largest application amount. In the production process of furan resin, raw materials comprise formaldehyde, furfuryl alcohol, urea and auxiliary additives, and process links in the production process have obvious influence on the utilization rate and the polymerization state of the raw materials and also have obvious influence on the service performance of products, including the adhesive strength and collapsibility of molding sand and the protection of casting environment.

Furan resin is widely used for high-temperature resistant anticorrosive coatings, high-temperature resistant insulating coatings, high-temperature resistant fireproof heat-insulating flame-retardant coatings and the like, but the furan resin has poor adhesion to a base material and reduces the mechanical strength of a paint film at higher temperature, so that the application of the furan resin is limited to a certain extent, and in addition, the wear resistance, the high-temperature resistance, the curing activity, the corrosion resistance, the wear resistance and the like of the furan resin still need to be further improved. The modification and doping of organic resins by using inorganic materials having excellent temperature resistance and insulation properties is a new research direction in recent years, and can effectively improve various properties of furan resins.

Disclosure of Invention

In order to solve the technical problems, the invention provides a preparation method of boronized furan resin, which is characterized in that furan resin is used as a carbon source, boric acid is added for boronizing to obtain the boronized furan resin, the graphitization degree of the furan resin can be effectively improved, so that the performances of the furan resin in various aspects such as high temperature resistance, curing activity and the like are improved, the synthesis process is mild and easy to control, gel curing is not easy to occur, the synthesis route is simple and easy to operate, and no wastewater is generated.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a preparation method of boronized furan resin comprises the following steps:

(1) adding solid formaldehyde and part of furfuryl alcohol into a reaction kettle, stirring and mixing, adding boric acid, and adjusting the pH value to 4.5-6 by using benzoic acid;

(2) adding a catalyst of zinc acetate under the acidic condition, carrying out catalytic reaction at the temperature of 130-150 ℃, and keeping the temperature for 2 hours to obtain a polymer;

(3) adding the rest furfuryl alcohol, benzoic acid and maleic anhydride, adjusting the pH to 3.0-3.5, reacting at 130-135 ℃, and preserving the temperature for 2.5 hours;

(4) adding sodium hydroxide solution to adjust the pH value to 7-8, cooling, adding methanol, an aldehyde removing agent and a coupling agent, and stirring and mixing uniformly;

(5) adjusting the pH value to be neutral, continuously stirring and discharging to obtain the product.

Preferably, the raw materials in each reaction stage are as follows in parts by weight: 15 parts of solid formaldehyde, 75-80 parts of furfuryl alcohol, 0.1-0.5 part of benzoic acid, 2-5 parts of boric acid, 0.2-0.5 part of maleic anhydride, 0.3 part of aldehyde removing agent, 3-5 parts of methanol and 0.4-0.8 part of coupling agent.

Further preferably, the weight parts of the raw materials in each reaction stage are as follows: 15 parts of solid formaldehyde, 76 parts of furfuryl alcohol, 0.1 part of benzoic acid, 5 parts of boric acid, 0.2 part of maleic anhydride, 0.3 part of aldehyde removing agent, 3 parts of methanol and 0.4 part of coupling agent.

Preferably, the adding amount of the furfuryl alcohol in the step (1) and the step (3) is 1: 1.

Preferably, the solid formaldehyde is paraformaldehyde with low polymerization degree, and the content is 90.0-99.9%.

Preferably, the coupling agent is N- (beta-aminoethyl) -gamma-aminopropylmethyldimethoxysilane.

Preferably, the maleic anhydride is maleic anhydride aqueous solution with the concentration of 13%.

Preferably, the concentration of the sodium hydroxide solution is 20-30%.

The beneficial effects of the invention are as follows:

1. according to the invention, the furan resin is used as a carbon source, the boric acid is used as a doping agent for promoting graphitization and improving electrochemical performance, and the doped boric acid can effectively improve the graphitization degree of the furan resin and improve the appearance and the electrochemical performance of the furan resin, so that the wear resistance, the thermal shock resistance and the shock absorption of the furan resin are improved, the fatigue resistance, the creep resistance, the corrosion resistance and the wear resistance are better, and the thermal expansion coefficient is smaller;

2. the raw material furfuryl alcohol is added twice, so that the boron adding reaction is more thorough, the effect is better, the first time of adding furfuryl alcohol is to ensure that boric acid is excessively reacted, the content of boron element in resin is increased, the second time of adding furfuryl alcohol is to reduce residual formaldehyde in reaction resin, the content of free formaldehyde is reduced, and the resin is more environment-friendly;

3. the pH value is adjusted by each process, so that the smooth reaction is facilitated, and the reaction efficiency is increased;

4. according to the invention, by improving the raw materials and the production process, the production process is milder and easier to control, the gel is not easy to cure, the synthetic route is simple and easy to operate, dehydration is not required, no wastewater is generated, the raw materials are easy to obtain, and the furan resin which contains boron, has good fluidity, low free formaldehyde, low viscosity, lower cost, energy conservation, environmental protection and higher strength is obtained and can be directly used for the production of steel castings and used as an intermediate of carbon-carbon composite materials;

5. in the invention, under an acidic condition, benzoic acid is used as a catalyst, the full reaction is ensured, boric acid is added for boronization to obtain boronized furan resin, boron is doped to ensure that the boronized furan resin has more excellent high temperature resistance and very high curing activity, a coating film can be dried at 100 ℃ for 5-10min and at room temperature for 30-60min, and the problem of adhesive reversion of the cured coating film is completely overcome;

6. the coupling agent is added in the preparation process, so that the strength of the resin is greatly improved.

Detailed Description

To facilitate understanding of those skilled in the art, the present invention will be further described with reference to specific examples: