阅读说明：本技术 一种合成聚甲基膦酸乙二醇酯的方法 (Method for synthesizing poly (ethylene glycol methyl phosphonate) ) 是由 秦善宝 吴多坤 单宝娜 郑伟欣 袁美 刘宝峰 杨金花 于 2021-09-06 设计创作，主要内容包括：一种合成聚甲基膦酸乙二醇酯的方法,向三口瓶中加入一定量的甲基膦酸二甲酯和乙二醇,同时加入复合催化剂磷钨酸铈和离子液体,复合催化剂的物质的量比为2：(1～4)；搅拌下滴加封端剂B-OH,进行封端处理；磁力搅拌下缓慢加热蒸馏,控制体系缓慢升温,当在确定温度下不再有馏分时,停止反应,趁热过滤；滤液先节pH值至3.0～4.0,温度设为75～100℃,保温降解,得到目标产物。本发明避免了单一催化剂或者金属催化剂引起的聚甲基膦酸乙二醇酯产品粘度过大和过低,产品酸度值过高等问题,节省了产品后加工的时间和成本。(A method for synthesizing poly (ethylene glycol methyl phosphonate) comprises the steps of adding a certain amount of dimethyl methyl phosphonate and ethylene glycol into a three-necked bottle, and simultaneously adding a composite catalyst of cerium phosphotungstate and ionic liquid, wherein the mass ratio of the composite catalyst is 2: (1-4); dropping end-capping reagent B-OH under stirring for end-capping treatment; slowly heating and distilling under magnetic stirring, controlling the system to slowly raise the temperature, stopping the reaction when no fraction is available at a certain temperature, and filtering while the reaction is hot; and (3) firstly adjusting the pH value of the filtrate to 3.0-4.0, setting the temperature to be 75-100 ℃, and preserving the heat for degradation to obtain a target product. The invention avoids the problems of overlarge and overlow viscosity, overhigh acidity value and the like of the poly (ethylene glycol methyl phosphonate) product caused by a single catalyst or a metal catalyst, and saves the time and the cost for post-processing the product.)

1. A method for synthesizing poly (ethylene glycol methyl phosphonate), which is characterized by comprising the following steps: the method comprises the following steps: adding a certain amount of dimethyl methylphosphonate and ethylene glycol into a three-necked bottle, and simultaneously adding a composite catalyst of cerium phosphotungstate and ionic liquid, wherein the mass ratio of the composite catalyst is 2: 1-4; dropping end-capping reagent B-OH under stirring for end-capping treatment; slowly heating and distilling under magnetic stirring, controlling the system to slowly raise the temperature, stopping the reaction when no fraction is available at a certain temperature, and filtering while the reaction is hot; and adjusting the pH value of the filtrate to 3.0-4.0, setting the temperature to 75-100 ℃, and performing heat preservation and degradation to obtain a target product.

2. The method for synthesizing poly (ethylene glycol methyl phosphonate) according to claim 1, wherein: the mass ratio of dimethyl methylphosphonate to ethylene glycol is 1: 1-2.

3. The method for synthesizing poly (ethylene glycol methyl phosphonate) according to claim 1, wherein: the reaction temperature is 160-165 ℃, and the reaction time is 4-6 hours.

4. The method for synthesizing poly (ethylene glycol methyl phosphonate) according to claim 1, wherein: the addition amount of the blocking agent B-OH is 1 percent of the mass of the dimethyl methylphosphonate.

5. The method for synthesizing poly (ethylene glycol methyl phosphonate) according to claim 1, wherein: the pH was adjusted using cerium phosphotungstate.

6. The method for synthesizing poly (ethylene glycol methyl phosphonate) according to claim 1, wherein: the thermal insulation degradation time is 4-8 hours, and the target product is light yellow viscous liquid poly (ethylene glycol methyl phosphonate).

Technical Field

The invention relates to a method for synthesizing poly (ethylene glycol methyl phosphonate), belonging to the technical field of flame retardant preparation.

Background

The poly (ethylene glycol methyl phosphonate) is a P-C bond-containing polymeric phosphonate flame retardant with high phosphorus content, and the molecular contains polar hydroxyl, phosphonate and nonpolar ethylene, so that the flame retardant has good compatibility with most polar or nonpolar high polymer materials. Meanwhile, hydroxyl contained in the poly (ethylene glycol methyl phosphonate) can participate in the polymerization reaction of epoxy resin, or can perform ester exchange reaction with high molecular compounds such as esters, and can also be dehydrated into ether with C-6 hydroxymethyl of cellulose, and can be used as a reactive phosphorus-containing flame retardant of the high molecular materials. The reaction of dimethyl methylphosphonate and glycol to produce polyethylene glycol methylphosphonate belongs to ester exchange reaction and can be catalyzed by acid, alkali, heteropoly acid and other catalysts. The catalyst has influence on the viscosity of the product, the viscosity of the product is too low, the fluidity is too high, and the catalyst is inconvenient to use as a flame retardant; too high viscosity, difficult dispersion and influence on use. The catalyst also has influence on the acid value of the product, and the problems of easy moisture absorption, easy migration and the like can occur due to the excessively high acid value. Therefore, the selection of a good catalyst is crucial to the production of poly (ethylene glycol methyl phosphonate). The ionic liquid has extremely low vapor pressure, is not easy to volatilize, has strong solubility, not only is a good chemical solvent, but also is a good catalyst for a plurality of reactions. The cerium phosphotungstate is a heavy metal complex and has good catalytic performance on ester exchange reaction.

Disclosure of Invention

The invention provides a method for synthesizing poly (ethylene glycol methyl phosphonate) in order to solve the problems that the viscosity of poly (ethylene glycol methyl phosphonate) products is too high and too low, the acidity value of the products is too high, and the like. The specific technical scheme is as follows: adding a certain amount of dimethyl methylphosphonate and ethylene glycol into a three-necked bottle, and simultaneously adding a composite catalyst of cerium phosphotungstate and ionic liquid, wherein the mass ratio of the composite catalyst is 2: (1-4); dropping end-capping reagent B-OH under stirring for end-capping treatment; slowly heating and distilling under magnetic stirring, controlling the system to slowly raise the temperature, stopping the reaction when no fraction is available at a certain temperature, and filtering while the reaction is hot; firstly, adjusting the pH value of the filtrate to 3.0-4.0, setting the temperature to 75-100 ℃, and performing heat preservation and degradation to obtain a target product; the mass ratio of dimethyl methylphosphonate to ethylene glycol is 1 (1-2); the reaction temperature is 160-165 ℃, and the reaction time is 4-6 hours; the addition amount of the end-capping reagent B-OH is 1 percent of the mass of the dimethyl methylphosphonate; adjusting the pH value by using cerium phosphotungstate; the thermal insulation degradation time is 4-8 hours, and the target product is light yellow viscous liquid poly (ethylene glycol methyl phosphonate).

The principle of the invention is as follows:

acid catalysis is needed for synthesizing the poly (ethylene glycol methyl phosphonate), and Lewis acid has the capability of accepting electrons and can accommodate pi electrons of P = O or lone pair electrons on an O atom, so that P shows more electropositivity and can easily perform nucleophilic reaction with nucleophilic groups such as alcoholic hydroxyl and the like. There are many common Lewis acid catalysts, such as ionic liquid, cerium phosphotungstate, aluminum chloride, gamma-Al 2O3, zinc oxide, etc.

Compared with the prior art, the invention has the beneficial effects that:

the invention provides a method for synthesizing poly (ethylene glycol methyl phosphonate), which takes dimethyl methyl phosphonate and ethylene glycol as raw materials, adopts cerium phosphotungstate and ionic liquid as composite catalysts, adopts a blocking agent B-OH to reduce the acidity value of the poly (ethylene glycol methyl phosphonate), and simultaneously utilizes the adjustment of pH and temperature to reduce the viscosity of the poly (ethylene glycol methyl phosphonate), thereby solving the problems of over-high viscosity or over-low viscosity and over-high acidity value of the poly (ethylene glycol methyl phosphonate) product caused by a single catalyst or a metal catalyst.

Detailed Description

The technical solutions of the present invention are further described below with reference to the following examples, but the present invention is not limited thereto, and any modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

A method for synthesizing poly (ethylene glycol methyl phosphonate) comprises the steps of adding a certain amount of dimethyl methyl phosphonate and ethylene glycol into a three-necked bottle, and simultaneously adding a composite catalyst of cerium phosphotungstate and ionic liquid, wherein the mass ratio of the composite catalyst is 2: (1-4); dropping end-capping reagent B-OH while stirring, and performing end-capping treatment to reduce the acidity value; slowly heating and distilling under magnetic stirring, controlling the system to slowly raise the temperature, stopping the reaction when no fraction is available at a certain temperature, and filtering while the reaction is hot; adjusting the pH value of the filtrate to 3.0-4.0, setting the temperature to 75-100 ℃, and preserving the heat to degrade high molecular compound poly (ethylene glycol methyl phosphonate) to obtain a target product; the mass ratio of dimethyl methylphosphonate to ethylene glycol is 1 (1-2); the reaction temperature is 160-165 ℃, and the reaction time is 4-6 hours; the addition amount of the end-capping reagent B-OH is 1 percent of the mass of the dimethyl methylphosphonate; adjusting the pH value by using cerium phosphotungstate; the thermal insulation degradation time is 4-8 hours, and the target product is light yellow viscous liquid poly (ethylene glycol methyl phosphonate).

The invention provides a method for synthesizing poly (ethylene glycol methyl phosphonate), which takes dimethyl methyl phosphonate and ethylene glycol as raw materials, adopts cerium phosphotungstate and ionic liquid as composite catalysts, adopts a blocking agent B-OH to reduce the acidity value of the poly (ethylene glycol methyl phosphonate), and simultaneously utilizes the adjustment of pH and temperature to reduce the viscosity of the poly (ethylene glycol methyl phosphonate), thereby solving the problems of over-high viscosity or over-low viscosity and over-high acidity value of the poly (ethylene glycol methyl phosphonate) product caused by a single catalyst or a metal catalyst.

The invention and its embodiments have been described above, without this being limitative. In summary, those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiments as a basis for designing or modifying other structures for carrying out the same purposes of the present invention without departing from the spirit and scope of the invention as defined by the appended claims.