Synthesis method for poly-N-vinylcaprolactam

A technology of vinyl caprolactam and synthesis method, applied in the synthesis field of obtaining poly-N-vinyl caprolactam, can solve the problems of long time, toxic solvent and the like

Inactive Publication Date: 2012-06-27
GANSU RES INSTION OF CHEM IND GRICI +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] The purpose of the present invention is to provide a synthetic method of poly-N-vinyl capro

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] Distill N-vinylcaprolactam (NVCL) under reduced pressure, then add it to VA-044 and absolute ethanol at a mass ratio of 1:0.1:15 into a three-necked flask, protect it with nitrogen, start stirring, and raise the temperature to 65°C. The reaction was stopped after 7 hours of reaction.

[0020] The solvent was distilled off under reduced pressure at 0.08 MPa at a temperature of 50 °C to obtain a colorless viscous liquid. Add tetrahydrofuran in an amount 4 times the volume of N-vinylcaprolactam to dissolve, and precipitate with n-hexane. Stand still, discard the supernatant, add ether to wash the precipitate, filter, and dry at 30°C to obtain the white powder product polyvinylcaprolactam (PNVCL). The average molecular weight is 31400.

Embodiment 2

[0022] Distill N-vinylcaprolactam (NVCL) under reduced pressure, then add it to VA-044 and water at a mass ratio of 1:0.1:7 into a three-necked flask, protect it with nitrogen and start stirring, raise the temperature to 65°C, and react for 7h After stopping the reaction.

[0023] The solvent was distilled off under reduced pressure at 0.08 MPa at a temperature of 50 °C to obtain a colorless viscous liquid. Add tetrahydrofuran in an amount 4 times the volume of N-vinylcaprolactam to dissolve, and precipitate with n-hexane. Stand still, discard the supernatant, add ether to wash the precipitate, filter, and dry at 30°C to obtain the white powder product polyvinylcaprolactam (PNVCL). The average molecular weight is 23400.

Embodiment 3

[0025] Distill N-vinylcaprolactam (NVCL) under reduced pressure, then add it to VA-044 and water at a mass ratio of 1:0.5:15 into a three-necked flask, protect it with nitrogen and start stirring, raise the temperature to 65°C, and react for 7h After stopping the reaction.

[0026] The solvent was distilled off under reduced pressure at 0.08 MPa at a temperature of 50 °C to obtain a colorless viscous liquid. Add tetrahydrofuran in an amount 4 times the volume of N-vinylcaprolactam to dissolve, and precipitate with n-hexane. Stand still, discard the supernatant, add diethyl ether to wash the precipitate, filter, and dry at 30°C to obtain the white powder product PNVCL. The average molecular weight is 12500.

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PUM

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Abstract

The invention is aimed at providing a synthesis method for poly-N-vinylcaprolactam, so as to solve the problems of long time and toxic solvent in the present polymerization process. The method comprises the following steps of: A, reaction: performing reduced pressure distillation on N-vinylcaprolactam, then adding the N-vinylcaprolactam, an initiator azodiisobutyl imidazoline hydrochloride and a solvent in a three-neck flask, charging nitrogen to protect and starting to stir, and heating to 65-80 DEG C, wherein the solvent is one of absolute ethyl alcohol and water, and the usage amount of the initiator is 0.1-0.5 folds of the mass of the N-vinylcaprolactam; and B, post-treatment: steaming away the solvent at 50 DEG C and under a reduced pressure of 0.08 MPa to obtain a colourless sticky liquid, adding tetrahydrofuran to dissolve, and separating out by n-hexane, standing, removing the supernatant, adding ethyl ether to precipitate, filtering, and drying at 30 DEG C to obtain the product poly-N-vinylcaprolactam. The synthesis method provided by the invention eliminates the harm on environment by the utilization of toxic solvent; and the average molecular weight detected by GPC (gel permeation chromatography) is greater than 10000-30000.

Description

technical field [0001] The invention relates to a synthesis method for obtaining poly-N-vinyl caprolactam from N-vinyl caprolactam monomers. Background technique [0002] Natural gas hydrate is an ice-like white solid substance formed by natural gas and water at low temperature and high pressure. Because most of the natural gas components are methane, it is also called methane hydrate. The formation of hydrates in the medium is very harmful to oil and gas production, storage and transportation. There are three crystal structures of natural gas hydrates that have been discovered so far, which are customarily called type I, type II and type H. The water molecules that form hydrates are called hosts, and the other components that form hydrates are called guests. The host water molecules are connected by hydrogen bonds to form some polyhedral cage holes, and the guest molecules of appropriate size can be filled in these cages to make them thermodynamically stable. [0003] Acc...

Claims

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Application Information

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IPC IPC(8): C08F126/06C08F6/00
Inventor 韩庆荣赵坤王琴张鹏云李春新
Owner GANSU RES INSTION OF CHEM IND GRICI
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