Method for preparing linear high molecular weight polyphenylene sulfide by utilizing pre-desalting method

A high-molecular-weight, polyphenylene sulfide technology, which is applied in the field of preparing linear high-molecular-weight polyphenylene sulfide by pre-desalination method, can solve the problems of poor product quality, wide molecular weight distribution, and insufficient environmental protection of the production process.

Active Publication Date: 2013-09-04
SHANDONG MINGHUA NEW MATERIAL CO LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The main problems of this method are: firstly, the controllability and reproducibility of the process is poor, and the product quality is unstable, so it can only be classified by subsequent analysis; secondly, the quality of the product is poor, and the molecular weight distribution is wide, so it is difficult to meet high-demand applications The third is that polyphenylene sulfide wraps the inorganic salt impurities in the reaction system during the polymerization process, especially the large amount of sodium chloride precipitated, which makes it difficult to remove these impurities, resulting in its presence in polyphenylene sulfide products. The content of sodium chloride is high, which causes serious corrosion of eq

Method used

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  • Method for preparing linear high molecular weight polyphenylene sulfide by utilizing pre-desalting method

Examples

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Effect test

Embodiment 1

[0022] 424g of lithium chloride was fully stirred and dissolved in 3000g of N-methylpyrrolidone, and then 560g of sodium hydrosulfide was added to fully stir and suspend. 2 Under atmospheric conditions, slowly heat to 80° C., react for 3 hours, and filter to obtain a solution of lithium hydrosulfide in N-methylpyrrolidone. The filter cake of sodium chloride was washed three times with 1000 g of hot N-methylpyrrolidone at 45° C. to obtain 570 g of high-purity white sodium chloride crystals.

[0023] in N 2 Under atmospheric conditions, heat the N-methylpyrrolidone solution of lithium hydrosulfide obtained above to 150° C., react until no hydrogen sulfide gas escapes in the system, and obtain a N-methylpyrrolidone suspension of lithium sulfide. Tail gas is absorbed with lye.

[0024] Add 735g of p-dichlorobenzene and 36g of lithium hydroxide to the N-methylpyrrolidone suspension of lithium sulfide obtained above, raise the temperature to 220°C, and generate by self-vaporizatio...

Embodiment 2

[0028] 445g of lithium chloride was fully stirred and dissolved in 4000g of N-methylpyrrolidone, and then 560g of sodium hydrosulfide was added to fully stir and suspend. 2 Under atmospheric conditions, slowly heat to 80° C., react for 3 hours, and filter to obtain a solution of lithium hydrosulfide in N-methylpyrrolidone. The filter cake of sodium chloride was washed twice with 1500 g of 30° C. hot N-methylpyrrolidone to obtain 560 g of high-purity white sodium chloride crystals.

[0029] in N 2 Under atmospheric conditions, heat the N-methylpyrrolidone solution of lithium hydrosulfide obtained above to 190° C., react until no hydrogen sulfide gas escapes in the system, and obtain a N-methylpyrrolidone suspension of lithium sulfide. Tail gas is absorbed with lye.

[0030]735g of p-dichlorobenzene and 30g of lithium hydroxide were added to the above-mentioned suspension of lithium sulfide in N-methylpyrrolidone, and the temperature was raised to 190°C for pre-polymerization ...

Embodiment 3

[0032] 430g of lithium chloride was fully stirred and dissolved in 5000g of N-methylpyrrolidone, and then 560g of sodium hydrosulfide was added to fully stir and suspend. 2 Slowly heated to 80° C. under atmospheric conditions, reacted for 3 hours, and filtered to obtain a solution of lithium hydrosulfide in N-methylpyrrolidone. The filter cake of sodium chloride was washed three times with 1000 g of hot N-methylpyrrolidone at 50° C. to obtain 565 g of high-purity white sodium chloride crystals.

[0033] in N 2 Under atmospheric conditions, heat the above-mentioned N-methylpyrrolidone solution of lithium hydrosulfide to 170° C., react until no hydrogen sulfide gas escapes in the system, and prepare a suspension of lithium sulfide in N-methylpyrrolidone. Tail gas is absorbed with lye.

[0034] 735g of p-dichlorobenzene and 40g of lithium hydroxide were added to the above-mentioned suspension of lithium sulfide in N-methylpyrrolidone, the temperature was raised to 220°C, and th...

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Abstract

The invention relates to a method for preparing linear high molecular weight polyphenylene sulfide by utilizing a pre-desalting method. The method comprises the steps of adding sodium sulfhydrate into NMP (N-methyl-2-pyrrolidone) dissolved with lithium chloride under the inert gas shielding, separating solid sodium chloride after reacting under the heating condition of 70-110 DEG C, obtaining an NMP solution of lithium hydrogen sulfide, continuing to heat to 150-190 DEG C till no hydrogen sulphide escapes, obtaining an NMP suspension of lithium sulfide, adding p-dichlorobenzene and a catalyzing amount of lithium hydroxide at a molar ratio of (0.95-1.1):1, performing and accomplishing polymerization reaction for generating a target product at 190-280 DEG C and 0.1-0.5 MPa, and collecting a precipitation product after cooling. The product is 284-289 DEG C in melting point, 50000-52000 in weight-average molecular weight, 2-3 in molecular weight distribution index, and less than 300ppm in chloride ion content. Since a great deal of sodium chloride is removed before the polymerization reaction, the method solves the problems that a product produced by the traditional method is high in sodium chloride content, and sodium chloride is difficult to remove to result in low quality of the product.

Description

technical field [0001] The invention relates to an improvement to the preparation method of linear high molecular weight polyphenylene sulfide. Background technique [0002] Polyphenylene sulfide (PPS) is polyphenylene sulfide, also known as polyphenylene sulfide, which is an important chemical engineering plastic, following polyoxymethylene (POM), polycarbonate (PC), polyamide (PA ), polybutylene terephthalate (PBT), and the sixth largest engineering plastic after modified polyphenylene oxide (MPPO), with excellent high temperature resistance, corrosion resistance, radiation resistance, flame retardancy, and balanced physical machinery Performance and excellent dimensional stability and excellent electrical properties, etc., are widely used as structural polymer materials, widely used as special engineering plastics after filling and modification, and can also be made into various functional films, Coatings and composite materials have been successfully applied in the fie...

Claims

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Application Information

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IPC IPC(8): C08G75/02C08G75/0259
Inventor 李晶晶杨琴罗芩李朝祥
Owner SHANDONG MINGHUA NEW MATERIAL CO LTD
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