Method for recycling NMP (N-Methyl Pyrrolidone) and LiCl in production of polyphenylene sulfide by using solvent extraction process

A polyphenylene sulfide and extraction process technology, applied in the field of NMP and LiCl, can solve problems such as lack of NMP and LiCl recovery methods, and achieve the effect of being conducive to large-scale industrial application, reasonable design, and efficient separation

Inactive Publication Date: 2018-04-20
ZHUHAI CHANGXIAN CHEM TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] In summary, the prior art still lacks an efficient and environmentally fri

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] In a 10-liter reactor, add Na 2 S·3H 2 O 1000g, lithium chloride 380g and NMP 3600g for dehydration reaction; after dehydration, add p-dichlorobenzene 1200g, NMP 1400g, fill with nitrogen, airtight, pre-polymerize at a low temperature of 220°C for 3 hours, and then heat up to 260°C for reaction After 3h, the reaction was completed and the temperature was lowered.

[0035] (1) The reaction mixture is filtered through a 1000-mesh precision filtration system to obtain 5116g filtrate 1 and 2465g filter residue 1, and the filtrate 1 is purified by rectification to obtain 4451g NMP;

[0036] (2) Add 1000 g of ethanol to the filter residue 1 obtained in step (1), dissolve the filter residue 1 by ultrasonic waves of 10KHz, then stir the mixed solution by magnetic force, and then filter the mixed solution to obtain the filter residue 2 and the filtrate 2;

[0037] (3) Repeat step (2) to filter 4 times, add 1000g of ethanol to each filter, collect the filtrate obtained by each ...

Embodiment 2

[0041] In a 10-liter reactor, add Na 2 S·3H 2 O 1000g, lithium chloride 380g and NMP 3600g for dehydration reaction; after dehydration, add p-dichlorobenzene 1200g, NMP 1400g, fill with nitrogen, airtight, pre-polymerize at a low temperature of 220°C for 3 hours, and then heat up to 260°C for reaction After 3h, the reaction was completed and the temperature was lowered.

[0042] (1) The reaction mixture is filtered through a 1500-mesh precision filtration system to obtain 4825g filtrate 1 and 2465g filter residue 1, and the filtrate 1 is purified by rectification to obtain 4421g NMP;

[0043] (2) Add 1000 g of dimethylformamide (DMF) to the filter residue 1 obtained in step (1), dissolve the filter residue 1 by 2KHz ultrasonic waves, then stir the mixed solution by magnetic force, and then filter the mixed solution to obtain filter residue 2 and filtrate 2 ;

[0044] (3) Repeat step (2) to filter 4 times, add 1000g of DMF to each filter, collect the filtrate obtained by eac...

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PUM

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Abstract

The invention discloses a method for recycling NMP (N-Methyl Pyrrolidone) and LiCl in production of polyphenylene sulfide by using a solvent extraction process. The method comprises the following steps: after polyphenylene sulfide production reactions are completed, filtering a reaction mixture through a precise filtering system, adding a certain amount of a solvent into filter residues, performing ultrasonic dissolution, filtering repeatedly, performing distillation on filtrate, respectively recycling the solvent, the NMP and the LiCl, washing the filter residues with a detergent, and respectively collecting a polyphenylene sulfide product and NaCl. Due to adoption of the precise filtering system, cleaning and filtration are implemented for multiple times with the solvent, a polyphenylenesulfide reaction mixed liquid is efficiently separated, the operation is simple, and large-scale industrial application is facilitated.

Description

technical field [0001] The invention relates to the technical field of polymer material synthesis and material recovery, in particular to a method for recovering NMP and LiCl in polyphenylene sulfide production through solvent extraction technology. Background technique [0002] Polyphenylene sulfide is a new polymer material, its English abbreviation is PPS. PPS has excellent heat resistance, flame retardancy, corrosion resistance and balanced mechanical and electrical properties, and is widely used in electronics, automobiles, machinery and chemical fields. [0003] At present, the relatively mature synthesis methods of polyphenylene sulfide commonly used at home and abroad generally use p-dichlorobenzene and aqueous sodium sulfide as reaction raw materials, and synthesize polyphenylene sulfide through steps such as dehydration and polycondensation. The production and synthesis process requires the action of solvents and catalysts, and the commonly used solvents and catal...

Claims

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Application Information

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IPC IPC(8): C08J11/02C08G75/0204C08G75/0281C01D15/04
CPCC01D15/04C08G75/0204C08G75/0281C08J11/02
Inventor 周鸿文杨伟明张德明
Owner ZHUHAI CHANGXIAN CHEM TECH
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