阅读说明：本技术 一种二氧化碳-环氧丙烷共聚物中催化剂的脱除方法 (Method for removing catalyst in carbon dioxide-propylene oxide copolymer ) 是由 李雅静 娄哲翔 蒋瑶 王笛 刘明亮 王业翔 宋立新 应利诚 聂琦 王献红 周庆海 于 2020-05-12 设计创作，主要内容包括：本发明公开了一种二氧化碳-环氧丙烷共聚物中催化剂的脱除方法,特点是包括以下步骤：(1)将环氧丙烷-二氧化碳共聚物和溶剂送入PPC溶解罐中溶解后得到环氧丙烷-二氧化碳共聚物混合液,溶剂包括二氯甲烷、三氯甲烷、四氯化碳、甲苯和二甲苯中的至少一种；(2)将环氧丙烷-二氧化碳共聚物混合液送入静态混合器中与酸液混合均匀后,再送入高速混合罐中进一步共混形成乳液；(3)将乳液送入油水分离器中分层,将得到的底部油相洗涤至中性,干燥后即得到催化剂完全脱除且残余重金属含量低于110ppm的环氧丙烷-二氧化碳共聚物,优点是产品中重金属含量低、产品纯度高。(The invention discloses a method for removing a catalyst in a carbon dioxide-epoxypropane copolymer, which is characterized by comprising the following steps of: (1) feeding the epoxypropane-carbon dioxide copolymer and a solvent into a PPC dissolving tank to dissolve to obtain an epoxypropane-carbon dioxide copolymer mixed solution, wherein the solvent comprises at least one of dichloromethane, trichloromethane, carbon tetrachloride, toluene and xylene; (2) sending the epoxypropane-carbon dioxide copolymer mixed solution into a static mixer to be uniformly mixed with acid liquor, and then sending into a high-speed mixing tank to be further blended to form emulsion; (3) sending the emulsion into an oil-water separator for layering, washing the obtained bottom oil phase to be neutral, and drying to obtain the epoxypropane-carbon dioxide copolymer with the catalyst completely removed and the residual heavy metal content lower than 110 ppm.)

1. A method for removing a catalyst in a carbon dioxide-propylene oxide copolymer is characterized by comprising the following steps:

(1) feeding the epoxypropane-carbon dioxide copolymer and a solvent into a PPC dissolving tank, controlling the temperature in the PPC dissolving tank to be 45-70 ℃ and the pressure to be 0.2-0.5MpgG, and dissolving to obtain an epoxypropane-carbon dioxide copolymer mixed solution, wherein the solvent comprises at least one of dichloromethane, trichloromethane, carbon tetrachloride, toluene and xylene;

(2) sending the epoxypropane-carbon dioxide copolymer mixed solution into a static mixer to be uniformly mixed with acid solution, and then sending the mixture into a high-speed mixing tank to be further blended to form emulsion, wherein the acid solution is an aqueous solution containing at least one of sulfuric acid, hydrochloric acid and benzenesulfonic acid;

(3) and (3) delivering the emulsion into an oil-water separator for layering, washing the obtained bottom oil phase to be neutral by using deionized water, and drying to obtain the propylene oxide-carbon dioxide copolymer product with the catalyst completely removed and the residual heavy metal content of less than 110 ppm.

2. The method for removing the catalyst from the carbon dioxide-propylene oxide copolymer according to claim 1, wherein: a PPC polymer feeding hole and a solvent feeding hole are formed in the top of the PPC dissolving tank in the step (1), a porous plate is communicated with the bottom of the PPC polymer feeding hole, and a nozzle is communicated with the bottom of the solvent feeding hole; the PPC dissolving tank is provided with a hot water jacket at the periphery and a stirrer in the axial direction.

3. The method for removing the catalyst from the carbon dioxide-propylene oxide copolymer according to claim 1, wherein: the feeding mass of the solvent in the step (1) is 0.3 to 0.9 time of that of the propylene oxide-carbon dioxide copolymer.

4. The method for removing the catalyst from the carbon dioxide-propylene oxide copolymer according to claim 1, wherein: the mass concentration of the acid component in the acid liquor in the step (2) is 0.5-5%, and the feeding mass of the acid liquor is 34-60% of that of the propylene oxide-carbon dioxide copolymer.

5. The method for removing the catalyst from the carbon dioxide-propylene oxide copolymer according to claim 1, wherein: and (3) a mixing stirrer is arranged in the high-speed mixing tank in the step (2), and the rotating speed of the mixing stirrer is 30-120 rpm.

Technical Field

The invention relates to a method for removing a catalyst, in particular to a method for removing a catalyst in a carbon dioxide-epoxypropane copolymer.

Background

One of the main raw materials for synthesizing carbon dioxide-propylene oxide copolymer (PPC) is carbon dioxide, which is a greenhouse gas having the greatest effect on global warming, and thus it is a common consensus that the control of carbon dioxide emissions has been achieved worldwide. The carbon dioxide-propylene oxide copolymer (PPC) can consume more than 40 percent of carbon dioxide in the total mass in the synthetic process, and can reduce the emission of a large amount of carbon dioxide. On the other hand, the carbon dioxide-propylene oxide copolymer (PPC) is a fully-degradable polymer, has the advantages of low cost, good transparency and gas barrier property, excellent processing performance and the like, can be widely applied to the field of films and packaging materials, replaces non-degradable plastic products, and has revolutionary significance for solving 'white pollution'.

The existing carbon dioxide-propylene oxide copolymer is directly synthesized by placing carbon dioxide (CO 2) and Propylene Oxide (PO) in a synthesis reaction kettle and reacting under the action of a catalyst, but the catalyst is not completely removed in a synthesized product, the heavy metal content is high, and the product performance is influenced. At present, no relevant research report about a method for removing a catalyst in a carbon dioxide-propylene oxide copolymer is published at home and abroad.

Disclosure of Invention

The invention aims to solve the technical problem of providing a method for removing a catalyst in a carbon dioxide-propylene oxide copolymer with low heavy metal content and high product purity.

The technical scheme adopted by the invention for solving the technical problems is as follows: a method for removing a catalyst in a carbon dioxide-propylene oxide copolymer comprises the following steps:

(1) feeding the epoxypropane-carbon dioxide copolymer and a solvent into a PPC dissolving tank, controlling the temperature in the PPC dissolving tank to be 45-70 ℃ and the pressure to be 0.2-0.5MpgG, and dissolving to obtain an epoxypropane-carbon dioxide copolymer mixed solution, wherein the solvent comprises at least one of dichloromethane, trichloromethane, carbon tetrachloride, toluene and xylene; the material viscosity is prevented from being too high after the temperature is too low and the pressure is too low, and the temperature and the pressure in the range ensure that the material has reliable fluidity;

(2) sending the epoxypropane-carbon dioxide copolymer mixed solution into a static mixer to be uniformly mixed with acid solution, and then sending the mixture into a high-speed mixing tank to be further blended to form emulsion, wherein the acid solution is an aqueous solution containing at least one of sulfuric acid, hydrochloric acid and benzenesulfonic acid;

(3) and (3) delivering the emulsion into an oil-water separator for layering, washing the obtained bottom oil phase to be neutral by using deionized water, and drying to obtain the propylene oxide-carbon dioxide copolymer product with the catalyst removed and the residual heavy metal content in the product lower than 110 ppm.

A PPC polymer feeding hole and a solvent feeding hole are formed in the top of the PPC dissolving tank in the step (1), a porous plate is communicated with the bottom of the PPC polymer feeding hole, and a nozzle is communicated with the bottom of the solvent feeding hole; the PPC dissolving tank is provided with a hot water jacket at the periphery and a stirrer in the axial direction. The polymer has high viscosity and is difficult to dissolve, and the PPC polymer is dissolved in the solvent by arranging a polymer dispersing device, a nozzle, a stirrer and a hot water jacket.

The feeding mass of the solvent in the step (1) is 0.3 to 0.9 time of that of the propylene oxide-carbon dioxide copolymer. If the amount of the solvent is too small, the catalyst cannot be completely removed, and if too much, the load of the subsequent devolatilization section is too large.

The mass concentration of the acid component in the acid liquor in the step (2) is 0.5-5%, and the feeding mass of the acid liquor is 34-60% of that of the propylene oxide-carbon dioxide copolymer. The zinc-based catalyst reacts with the acid liquor and then enters the water phase to achieve the purpose of removing the catalyst, wherein the acid liquor is added in an excessive amount.

And (3) a mixing stirrer is arranged in the high-speed mixing tank in the step (2), and the rotating speed of the mixing stirrer is 30-120 rpm. The acid liquor and the PPC solution are uniformly mixed, so that the aim of thoroughly removing the catalyst is fulfilled.

Compared with the prior art, the invention has the advantages that: the invention discloses a method for removing a catalyst from a carbon dioxide-propylene oxide copolymer for the first time, wherein the copolymer is subjected to static mixing, high-speed mixing and layering by a layering device in sequence to obtain the catalyst-removed copolymer, and the product obtained by the method has low heavy metal content, high product purity and is more environment-friendly.

Drawings

FIG. 1 is a schematic flow chart of the apparatus for removing the catalyst from the carbon dioxide-propylene oxide copolymer according to the present invention.

Detailed Description