Method of production of cross-linked spherical granules of divinylbenzene co-polymers

Abstract

Production of monodisperse spherical granules of divinylbenzene co-polymers, used as sorbents, utilizes precipitative polymerization of divinylbenzene with substituted styrenes or derivatives of acrylic acid in the environment of acetonitrile in presence of an initiator and a stabilizer at the temperature ranging from 50 ° C. to 82 ° C. and mixing. Amides of aliphatic carbonic acids are used as low-molecular stabilizers, with the common formula: ##STR00001##
where R.sub.1 is an alkyl with 5 to 10 carbon atoms, an aryl alkyl with 7 to 10 carbon atoms; R.sub.2 R.sub.3 is an alkyl with 1 to 4 carbon atoms, or biradical with 3 to 5 carbon atoms; m ia a total number of carbon atoms in the direct or branched chain ranging from 2 to 14; the concentration of the stabilizer in the reaction mixture is from 2.Math.10.sup.−3 to 0.2 mole/1; the size of the monodisperse microspheres ranges between 0.2 and 4.0 micron.

Claims

1. A method of producing monodisperse cross-linked spherical granules of divinylbenzene co-polymers, the method comprising precipitately polymerizing divinylbenzene with substituted styrenes or derivatives of acrylic acid in an environment of acetonitrile in the presence of an initiator and a stabilizer at a temperature during mixing; and using a low-molecular stabilizer of amides of aliphatic carbonic acids as the stabilizer in the co-polymerization process, the amides of aliphatic carbonic acids having a common formula I and/or II: ##STR00004## where radical R.sub.1, is an alkyl with a number of carbon atoms from 5 to 10, an aryl alkyl with a total number of carbon atoms from 7 to 10; radicals R.sub.2, R.sub.3 are an alkyl with a number of carbon atoms from 1 to 4, or a biradical with a number of carbon atoms from 3 to 5, m—a total number of carbon atoms in a direct of branched chain being from 2 to 14; and wherein a concentration of the stabilizer ranges from 2.Math.10.sup.−3 to 0.2 mole/1.

2. The method according to the claim 1, wherein N, N-dimethyl hexanamide, N.sup.1,N.sup.1,N.sup.10,N.sup.10 -tetramethyl decandiamide N.sup.1,N.sup.1,N.sup.12,N.sup.12-tetramethyl dodekandiamide or N,N-dimethyl octanamide are used as the stabilizer.

3. The method according to the claim 1 carried out at the temperature selected from a range from 50° C. to 82° C.

Description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(1) According to the present invention, its stated and other objects are reached by the precipitative polymerization of divinylbenzene and its co-polymerization with other monomers at the temperature of 50-82° C. in the environment of acetonitrile with shaking in presence of an initiator and low-molecular stabilizer.

(2) The method of the present invention uses amides of aliphatic carbonic acids of the common formula (I) and (II) as stabilizers, because they are low-molecular surfactant stabilizers

(3) ##STR00002##

(4) where

(5) radical R.sub.1—alkyl with the number of carbon atoms 5-10,aryl alkyl with common number of carbon atoms 7-10;

(6) radicals R.sub.2, R.sub.3—alkyl with the number of carbon atoms 1-4,or biradical with the number of carbon atoms 3-5.

(7) m—total number of carbon atoms in the direct or branched chain equal to 2-14.

(8) Amides containing 8-14 carbon atoms are the most effective stabilizers. The effect of the stabilizer is to a large extent determined by its chemical nature and depends mainly on the ratio of polar and non-polar parts of a molecule. The microspheres' size is in the bell-shaped dependence on the concentration of the stabilizer, as it is the result of the effect of two factors: inturgescence of the microspheres and increase of colloidal stability of the system. According to the present invention, the concentration of low-molecular stabilizer in the reaction mixture is between 2.Math.10.sup.−3 mole/l and 0.2 mole/l at concentrations higher than 0.2 mole/l the microspheres with bimodal size distribution are formed.

(9) According to this method, technology divinylbenzene containing 50 to 80% of isomeric meta- and para-divinylbenzenes mixed with meta- and para-ethylstyrenes can be used as monomer. It is also possible to produce co-polymers containing at least 45% of divinylbenzene, where the derivatives of acrylic acid, such as alkyl acrylates, alkyl metacrylates, in particular, glicidyl acrylate, substituted styrenes, such as alkyl styrenes, vinylbenzyl chloride, vinylbenzyl glicidyl ether, vinylbenzyl acetate can be used as co-monomers.

(10) The total concentration of monomer in the solution is between 2 and 15%. The application of concentrations lower than 2% is not efficient as the outcome of the polymer is reduced due to the increase of possibility of radicals recombination and ineffective use of the initiator. The stability of the colloidal system is decreased as the concentration of monomer increases, and at the concentration of more than 15% the microspheres coagulation in the whole volume of the system is observed.

(11) The initiators of azo-type, AIBN in the concentration of 0-10% of the monomer weight, mainly 2-4% of the monomer weight, are used as the initiators.

(12) The mixing of the reaction mass is performed by a few methods: by boiling the reaction mass or by using upper-driving mechanic mixer or shaker. Application of mixing methods of low intensity allows to use higher concentrations of the monomer, which allows to increase the outcome of the product from the volume unit of the reaction mixture.

(13) The substantial difference of the suggested method of production of monodisperse cross-linked spherical granules of divinylbenzene co-polymers is the performance of the process in presence of low-molecular stabilizer, which is an amide of an aliphatic acid of the common formula

(14) ##STR00003##

(15) where

(16) radical R.sub.1—alkyl with the number of carbon atoms 5-10,aryl alkyl with the total number of carbon atoms 7-10;

(17) radicals R.sub.2, R.sub.3—alkyl with the number of carbon atoms 1-4,or biradical with the number of carbon atoms 3-5.

(18) m—total number of carbon atoms in the direct or branched chain equal to 2-14.

(19) The inventive method allows to produce monodisperse microspheres of divinylbenzene co-polymers of the required size between 0.2 and 4.0 micron and containing at least 45% of linking agent under conditions, providing the maximum outcome of the target product per volume unit of the reaction mixture. According to this invention, the outcome of the polymer is 18-65 g per 1 l of the mixture at the total outcome in the reaction of 47-73%, which is determined only by the concentration of the components in the source solution.

(20) The industrial applicability of the inventive method is proved by the following examples.

EXAMPLE 1

(21) Acetonitrile, monomer with the concentration of the required percent of the total volume of the reaction mass, the initiator (AIBN) in the amount of 2% of monomer weight and the stabilizer sample weight are placed into the three-necked reaction vessel equipped with a reverse cooler and a capillary down to the bottom. The content of the reactor is blown off during 30 minutes with nitrogen to remove oxygen. The reaction mass is further placed into the oil bath, heated beforehand, and heat to the temperature of 50-82° C. After finishing the reaction and cooling the reaction mass the polymer is filtered, washed by tetrahydrofurane and dried to the stationary mass. The experimental results with the said stabilizers and their concentration in the reaction mixture are shown in the Table.

(22) TABLE-US-00001 Concentration in Average micro- the mixture wt. Concentration, sphere size, N Stabilizer %. Monomer vol. %. micron. PDI.sup.1 Outcome, % 1 N.sup.1,N.sup.1,N.sup.10,N.sup.10-Tetramethyl dekan- 0.5 DVB-80 4 0.9 1.05 48 2 diamide, (IIa) 1 2.2 1.04 47 3 1.75 2.4 1.08 47 4 2.5 1.6 1.03 49 5 N,N-dimethyl hexanamide, (Ia) 0.5 DVB-80 4 1.6 1.06 46 6 1 2.6 1.03 48 7 1.75 3.2 1.09 50 8 2.5 — .sup.2 — 47 9 N.sup.1,N.sup.1,N.sup.12,N.sup.12-tetramethyl dodekan- 1 DVB-80 4 1.2 1.04 49 diamide, (IIb) 10 IIa 0.5 DVB-55 4 2.9 1.08 49 11 Ia 1.78 DVB-80 and EA.sup.3 4 0.8 1.11 46 12 IIa 0.5 DVB-80 and 4 2.9 1.07 48 VBGE.sup.4 13 Mixture Ia and IIa 0.1% and 0.3% DVB-80 6 2.8 1.1  56 14 Mixture Ia and IIb 0.8% and 0.1% DVB-80 4 2.7 1.02 .sup. 73.sup.5 15 Absent — DVB-80 4 3.5 1.12 47 .sup.1Polydispersion index. .sup.2 Bimodal distribution. .sup.3Ethyl acrylate; Monomer ratio 3.35/1 (wt.) respectively. .sup.4Vinyl benzyl glicidyl ether; monomer ratio 3.75/1 (wt.) respectively. .sup.54% AIBN of monomer weight is loaded.