阅读说明：本技术 一种桦木醇基耐水解阻燃性聚酯多元醇及其制备方法 (Birch alcohol-based hydrolysis-resistant flame-retardant polyester polyol and preparation method thereof ) 是由 管兵 夏峰 熊治海 于 2020-07-10 设计创作，主要内容包括：本发明提供了一种桦木醇基耐水解阻燃性聚酯多元醇及其制备方法,属于化工合成技术领域；本发明中通过将己二酸、间苯二甲酸、桦木醇和丙二醇脱水反应,然后加入催化剂反应,接着加入高分子量环氧化合物反应得到所述桦木醇基耐水解阻燃性聚酯多元醇；制备得到的聚酯多元醇具有良好的耐水解性和阻燃性,并且具有很好的物理、机械和化学性能。(The invention provides birch alcohol-based hydrolysis-resistant flame-retardant polyester polyol and a preparation method thereof, belonging to the technical field of chemical synthesis; in the invention, adipic acid, isophthalic acid, betulin and propylene glycol are subjected to dehydration reaction, then a catalyst is added for reaction, and then a high molecular weight epoxy compound is added for reaction to obtain the betulin-based hydrolysis-resistant flame-retardant polyester polyol; the prepared polyester polyol has good hydrolysis resistance and flame retardance, and has good physical, mechanical and chemical properties.)

1. A preparation method of birch alcohol-based hydrolysis-resistant flame-retardant polyester polyol is characterized by comprising the following steps:

(1) putting dibasic acid and dihydric alcohol into a reaction kettle, performing dehydration reaction for 2 hours at 135-140 ℃, then heating to 200 ℃, and continuing to dehydrate for 3 hours; the dibasic acid is a mixture of adipic acid and isophthalic acid, and the dihydric alcohol is a mixture of betulin and propylene glycol;

(2) adding catalyst and charging N₂Reacting in the reaction kettle, and cooling after the reaction is finished; then adding a high molecular weight epoxy compound, and stirring to obtain the betulin-based hydrolysis-resistant flame-retardant polyester polyol.

2. The preparation method of the birch alcohol-based hydrolysis-resistant flame-retardant polyester polyol as claimed in claim 1, wherein in the step (1), the molar ratio of the dihydric alcohol to the dibasic acid is 1.1-1.3: 1-1.07.

3. The method for preparing birch alcohol-based hydrolysis-resistant flame-retardant polyester polyol according to claim 1, wherein the molar ratio of adipic acid to isophthalic acid is 1.19: 1; the mol ratio of the betulin to the propylene glycol is 0.8-1.2: 3.5-4.1.

4. The method for preparing birch alcohol-based hydrolysis-resistant flame-retardant polyester polyol according to claim 1, wherein in the step (1), the temperature rise rate is 5 ℃ min^-1。

5. The preparation method of the birch alcohol-based hydrolysis-resistant flame-retardant polyester polyol according to claim 1, wherein in the step (2), the catalyst is tetrabutyl titanate, and the amount of the catalyst is 10-200 ppm.

6. The method for preparing birch alcohol-based hydrolysis-resistant flame-retardant polyester polyol according to claim 1, wherein in the step (2), the N is charged₂The pressure of (a) is 200-400 Pa, and the reaction temperature is 200 ℃.

7. The preparation method of the birch alcohol-based hydrolysis-resistant flame-retardant polyester polyol according to claim 1, wherein in the step (2), the temperature reduction condition is as follows: when the acid value of the polyester polyol in the reaction kettle is lower than 0.5mg KOH/g, the temperature is reduced to 135 ℃.

8. The method for preparing a birch alcohol-based hydrolysis-resistant flame-retardant polyester polyol according to claim 1, wherein in the step (2), the stirring is performed until the acid value of the polyester polyol is less than 0.1 mg KOH/g.

9. The birch alcohol-based hydrolysis-resistant flame-retardant polyester polyol prepared by the method according to any one of claims 1 to 8, wherein the polyester polyol is prepared by firstly carrying out dehydration reaction on adipic acid, isophthalic acid, birch alcohol and propylene glycol, then adding a catalyst for polycondensation reaction, and finally adding a high-molecular-weight epoxy compound for reaction.

10. The birch alcohol-based hydrolysis resistant flame retardant polyester polyol of claim 9, wherein the acid value of the polyester polyol is less than 0.1 mg KOH/g.

Technical Field

The invention belongs to the technical field of chemical synthesis, and particularly relates to birch alcohol-based hydrolysis-resistant flame-retardant polyester polyol and a preparation method thereof.

Background

Polyester polyols are polyols widely used in polyurethane systems, and are widely used in the preparation of polyurethane elastomers, polyurethane foams, coatings, adhesives, rigid sponges, sealants and the like. The polyester polyol molecules contain more ester groups, amino groups and other polar groups, and the polyester polyol has strong cohesive strength and adhesive force, high strength and wear resistance; meanwhile, the polyester polyol also has good oil resistance and solvent resistance. However, polyester polyols still have the disadvantages of poor hydrolysis resistance and flammability. Under the high temperature condition, the residual acid in the polyester polyol can catalyze the hydrolysis of the polyester polyol, and the prepared product is easy to burn at a certain temperature. At present, the flame retardant property of polyester polyol is improved by adding halogen, but the halogen flame retardant may generate toxic and harmful gas.

Process control is also a critical factor affecting product performance during the preparation of polyester polyols. The heating rate of esterification, the amount of catalyst used, the dehydration time, the post-treatment and the like all affect the hydroxyl acid value, the chromaticity, the activity and the molecular weight distribution of the polyester polyol, and further affect the performance of the polyester polyol.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides birch alcohol-based hydrolysis-resistant flame-retardant polyester polyol and a preparation method thereof. According to the invention, adipic acid, isophthalic acid, betulin and propylene glycol are subjected to dehydration reaction, then a catalyst is added for reaction, and then a high molecular weight epoxy compound is added for reaction to obtain the betulin-based hydrolysis-resistant flame-retardant polyester polyol.

The invention provides a birch alcohol-based hydrolysis-resistant flame-retardant polyester polyol, which is prepared by firstly carrying out dehydration reaction on adipic acid, isophthalic acid, birch alcohol and propylene glycol, then adding a catalyst for polycondensation reaction, and finally adding a high-molecular-weight epoxy compound for reaction; the acid value of the polyester polyol is less than 0.1 mg KOH/g.

The invention also provides a preparation method of the birch alcohol-based hydrolysis-resistant flame-retardant polyester polyol, which comprises the following steps:

(1) putting dibasic acid and dihydric alcohol into a reaction kettle, performing dehydration reaction for 2 hours at 135-140 ℃, then heating to 200 ℃, and continuing to dehydrate for 3 hours; the dibasic acid is a mixture of adipic acid and isophthalic acid, and the dihydric alcohol is a mixture of betulin and propylene glycol;

(2) adding catalyst and charging N₂After the reaction is finished, the reaction is carried out in a reaction kettleCooling; then adding a high molecular weight epoxy compound, and stirring to obtain the betulin-based hydrolysis-resistant flame-retardant polyester polyol.

Further, in the step (1), the molar ratio of the dihydric alcohol to the dibasic acid is 1.1-1.3: 1-1.07.

Further, the molar ratio of adipic acid to isophthalic acid is 1.19: 1; the mol ratio of the betulin to the propylene glycol is 0.8-1.2: 3.5-4.1.

Further, in the step (1), the temperature rise rate is 5 ℃ min^-1。

Further, in the step (2), the catalyst is tetrabutyl titanate, and the dosage of the catalyst is 10-200 ppm.

Further, in the step (2), the charging is carried out by N₂The pressure of the reaction kettle is 200-400 Pa, and the temperature in the reaction kettle is 200 ℃.

Further, in the step (2), the temperature reduction condition is as follows: when the acid value of the polyester polyol in the reaction kettle is lower than 0.5mg KOH/g, the temperature is reduced to 135 ℃.

Further, in the step (2), the stirring is performed until the acid value of the polyester polyol becomes 0.1 mg KOH/g or less.

The invention has the beneficial effects that:

in the invention, betulin is added in the preparation process of polyester polyol to improve the flame retardant property of the polyester polyol. Betulin has high carbon content, and can generate a layer of carbon with enough thickness during combustion, and the carbon can cover the surface of combustible materials to isolate air and prevent the combustible materials from further combustion, thereby achieving the flame-retardant effect. Moreover, the betulin is extracted from the birch, has wide raw material source, is green and has no pollution.

When the polyester polyol is prepared, the epoxy compound with high molecular weight is added into a reaction system, and the ring opening of the epoxy compound is reacted with unreacted acid, so that the acid value of the polyester polyol is further reduced, the polyester polyol is prevented from being hydrolyzed by the catalysis of residual acid in the polyester polyol, and the hydrolysis resistance of the polyester polyol is further improved.

The invention has strict requirements on the dosage and the adding time of the catalyst by controlling the process. In the invention, the catalyst is added after most of water is removed from the polyol system, so that the catalyst can be prevented from being hydrolyzed, and the catalytic efficiency is improved; in addition, the addition amount of the catalyst added in the invention is only 10-200 ppm, the synthesis time of the polyester polyol in which a small amount of the catalyst is added can be reduced, the risk of yellowing of the polyester polyol due to long-time heating is reduced, the molecular weight distribution of the polyester polyol is narrower, and the improvement of the physical mechanical and chemical properties of the polyester polyol is facilitated.

Detailed Description

The present invention is further illustrated by the following specific examples, but the scope of the invention is not limited thereto.