Recovery method of N-methylpyrrolidone solvent in polyphenylene sulfide synthesis slurry

A technology of methylpyrrolidone and a recovery method is applied in the field of recovery of N-methylpyrrolidone solvent in polyphenylene sulfide synthesis slurry, and can solve the problems of complex process, high equipment cost, large power consumption and the like

Active Publication Date: 2016-08-31
LANZHOU UNIVERSITY OF TECHNOLOGY +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although the purity of NMP recovered by this method is higher than that of the solvent extraction method, it needs to set up a special flash tank, which has the disadvantages of high equipment cost, complicated process, large power consumption, and high recovery cost.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044] Add 500ml of N-methylpyrrolidone, 160g of p-dichlorobenzene, 78g of anhydrous sodium sulfide, 7g of lithium chloride and 4g of sodium hydroxide in a 1000ml titanium autoclave, install the device, and heat up to 185°C under stirring. The stirring rate was controlled to 150 r / min, and the reaction was stopped after 7.5 hours of reaction to obtain a synthetic slurry of polyphenylene sulfide.

Embodiment 2

[0046] Get 200ml of the polyphenylene sulfide synthesis slurry obtained in Example 1, centrifuge for 10min under the condition of 6000rpm at a rotating speed, add 600mL of water to the centrifuged liquid obtained by centrifugation, and let it settle for 20min to make the water-insoluble PPS low molecular weight The polymer is precipitated, and centrifuged again under the condition of 6000rpm for 10min to remove the PPS particles and PPS oligomers in the liquid to obtain a solution mainly containing water, NMP, sodium hydroxide and inorganic salts, and then use 20% mass concentration Adjust the pH of the solution to 6.5 with hydrochloric acid. Under the protection of nitrogen, keep the vacuum degree of 0.090MPa and conduct the first rectification under reduced pressure at a temperature of 70°C. The rectification time is 30min to remove water and dichloride. Benzene (DCB) to obtain a solution mainly containing NMP and inorganic salts. After the first rectification, the rectificat...

Embodiment 3

[0049] Get 200ml of the polyphenylene sulfide synthesis slurry obtained in Example 1, centrifuge for 20min under the condition of 8000rpm at a rotating speed, add 1000mL of water to the centrifuged liquid obtained by centrifugation, and let it settle for 20min to make the water-insoluble PPS low molecular weight The polymer is precipitated, and centrifuged again under the condition of 8000rpm for 20 minutes to remove the PPS particles and PPS oligomers in the liquid to obtain a solution mainly containing water, NMP, sodium hydroxide and inorganic salts, and then use 30% mass concentration Adjust the pH of the solution to 7.5 with hydrochloric acid. Under the protection of nitrogen, keep the vacuum degree of 0.1MPa and conduct the first rectification under reduced pressure at a temperature of 70°C. The rectification time is 20 minutes to remove water and p-dichloride. Benzene (DCB) to obtain a solution mainly containing NMP and inorganic salts. After the first rectification, the...

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Abstract

The invention relates to a recovery method of an N-methylpyrrolidone (NMP) solvent in polyphenylene sulfide (PPS) synthesis slurry. The process includes: subjecting the produced PPS synthesis slurry centrifugal separation, carrying out water precipitation, centrifugation and other steps on the obtained centrifugate to remove PPS particles and PPS oligomers, then using diluted hydrochloric acid to perform treatment, adjusting the pH to 6.5-7.5, under the protection of nitrogen, maintaining a vacuum degree of 0.090-0.10MPa and a temperature of 70-90DEG C, performing pressure reduced rectification, at the same time using a thermal insulation material to conduct thermal insulation on a rectification device, when water and p-dichlorobenzene are completely distilled off, conducting heating to 150-170DEG C, and performing rectification to obtain NMP. According to the method, the NMP recovery rate reaches 95%, and the purity reaches more than 99%.

Description

technical field [0001] The invention relates to the technical field of solvent recovery, in particular to a method for recovering N-methylpyrrolidone solvent in polyphenylene sulfide synthesis slurry. Background technique [0002] N-methylpyrrolidone (N-methylpyrrolidone) referred to as NMP, the molecular formula is C 5 h 8 ON, molecular weight 99.13, colorless transparent oily substance, slightly ammoniacal odor, miscible with water in any proportion, almost completely mixed with all solvents, with strong polarity, low viscosity, strong solvency, non-corrosive, low toxicity , strong biodegradability, low volatility and other advantages. Due to its many advantages, NMP is often used as an important chemical raw material. Among the many uses of NMP, in terms of usage, its usage is undoubtedly the largest when used as a solvent for polymer reactions, especially in recent years with the rise of the polyphenylene sulfide (PPS) industry, making the use of NMP The usage is lar...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08J11/02C08L81/02
CPCC08J11/02C08J2381/02
Inventor 欧玉静欧中亚朱亚龙李春雷
Owner LANZHOU UNIVERSITY OF TECHNOLOGY
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