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Polyacrylonitrile particles by surfmer polymerization and sodium removal by chemical exchange

A technology of polyacrylonitrile and particles, which is applied in the field of polyacrylonitrile particle synthesis, can solve the problems of harmful carbonization, lack of shape uniformity, etc., and achieve an easy-to-control effect

Inactive Publication Date: 2004-04-28
SOLUTIA INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In this carbonization method, in order to obtain good results, the uniformity of particle shape is necessary. However, in the prior art, acrylic microparticles are prepared simply by crushing larger particles, so uniformity in shape cannot be obtained.
And sodium ions are detrimental to this carbonation

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0040] The following is an example of continuous aqueous phase dispersion polymerization, a continuously stirred (2 layers are 45 degree angle 6 blade agitator, rotating speed is 600rpm) 3.5 liter tank reactor, kept at 55 ° C, a certain amount of The feed added into the reactor is 60 minutes to control the average residence time, and the pH value is controlled at about 3, and the total feed composition is listed in Table 2.

[0041] The aqueous solution of sodium persulfate (oxidant, initiator), sodium bisulfite (reductant, activator), ferrous or ferric iron (redox catalyst) and sulfuric acid (controlling PH value) is added to initiate the polymerization reaction. Under these conditions, the conversion rate of monomer into polymer reaches 86.5%, and finally polymer contains 3.1wt% sodium methallyl sulfonate (sulfonate ion 200meq / kg polymer), 3.9wt% Vinyl acetate and others are all acrylonitrile, with an average particle size of 2.8 microns and a bell-shaped size distribution c...

Embodiment 2

[0054] The following is an example of continuous aqueous phase dispersion polymerization containing different ionic monomers, a continuously stirred (2 layers of 45-degree angle 6-blade stirrer, rotating speed of 400rpm) 3.5 liter tank reactor maintained at 50 ° C, with A certain amount of feed is added to the reactor at a certain rate to control the average residence time to be 75 minutes, and the pH value is controlled at about 3.15. The total material composition is listed in Table 3.

[0055] The conversion rate of the monomer obtained under these conditions into polymer is 82.7%, containing 5.0wt% p-sulfophenyl methallyl ether sodium (sulfonate ion 200meq / kg polymer), 4.2% in the final polymer The wt% vinyl acetate and others are acrylonitrile. The average particle size was 28 microns, and the particle size distribution curve was bell-shaped, wherein 10 wt% of the particles were smaller than 11 microns and 10 wt% of the particles were larger than 56 microns. Although usi...

Embodiment 3

[0067] The following are examples of continuous aqueous phase dispersion polymerization with different surfactant monomers. A continuously stirred (2-layer 6-blade stirrer at a 45-degree angle at 600 rpm) 3.5-liter tank reactor maintained at 50°C with a certain amount of feed added to the reactor at a rate to control the average residence time The time is 75 minutes, the pH value is controlled at about 3.0, and the total material composition is listed in Table 4.

[0068] Table 4 total material composition

[0069] compound quantity unit

[0070] Acrylonitrile monomer 97.0 parts

[0071] Vinyl acetate monomer 0.0 parts

[0072] Itaconic acid 3.0 servings

[0073] Water 250.0 parts

[0074] Sodium persulfate (initiator) 0.33 % relative to monomer

[0075] Sodium bisulfite such as sulfur dioxide (activator) 0.74 % relative to the monomer

[0076] Iron (ferrous iron or ferric iron) 1.6 PPM content relative to the monomer

[0077] sulfuric acid trace

[0078] Th...

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Abstract

The present invention relates to an acrylic polymer particle which is consistently and substantially spherical in shape and which has a mean diameter that can be predetermined from about 30 microns in diameter to about 5 microns or less. Polyacrylonitrile is synthesized in an aqueous dispersion polymerization with an ionic monomer or ''surfmer'' to attain a narrow particle size distribution with a mean diameter as low as approximately 3+ / -1.5 microns which is characteristic of an emulsion polymerization. The polymer comprises the ionic monomer and, optionally, a neutral comonomer. The mean particle size is dependent on the concentration of the ionic monomer present, the particular ionic monomer or monomers selected, and the counterion associated with the ionic monomers, the persulfate initiator, and the bisulfite activator. The counterions, often sodium ions, can be removed from the polymer particles by ion exchange with quarternary ammonium compounds.

Description

technical field [0001] The present invention generally relates to a process for the synthesis of polyacrylonitrile particles. Background technique [0002] Acrylonitrile and its comonomers can be polymerized by a number of well known free radical methods. All industrial methods are based on free-radical polymerization, because free-radical polymerization has an easy-to-control polymerization rate, including whiteness, molecular weight, linearity, required comonomers and in most cases the ability to bind dye sites, etc. performance balance. The most widely used polymerization method in the acrylic fiber industry is aqueous phase dispersion polymerization or suspension polymerization. Aqueous dispersion polymerization as a variation of suspension polymerization is the most commonly used industrial method. Water is the continuous phase, water acts as a convenient heat transfer medium and cooling medium, and the polymer can be easily recovered by filtration or centrifugation....

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08F4/06C08F4/34C08F8/44C08F212/14C08F220/44C08F228/02
CPCC08F220/44C08F8/44
Inventor B·E·瓦德G·J·卡波尼
Owner SOLUTIA INC