SU1481236A1 - Method of producing copolymers with moisture-retaining and thickening properties - Google Patents

Abstract

The invention relates to the production of crosslinked copolymers of acrylic acid or acrylic acid and acrylamide, which have an increased water-holding and thickening ability. The invention makes it possible to obtain a copolymer of acrylic acid or acrylic acid with acrylamide and a crosslinking polyfunctional reagent with high water retention (degree of swelling in water is 1460-3300 g / g, in a 1% aqueous solution of NACL 126-163 g / g) while maintaining good thickening ability. The effect is achieved by using as a cross-linking polyfunctional reagent 0.05-0.12 wt.% From the reaction mixture of water-soluble allyl ether (allyl carboxymethylcellulose, allyloxyethylcellulose, allyloxypropylcellulose, allylmethylcellulose, allyloxyethylcellulose, allyloxypropylcellulose, and the allylmethylcellulose), and a mixture of allylmethylcellulose; , concentration / s / monomers 25-35 wt.% from the reaction mixture. As an initiator, the reaction mixture containing cobalt (0.30-1.00) is used ^. 10 ^-3 mol / l, and as a reaction mixture - the product of the electrolytic oxidation of cobalt acetate / p / in concentrated acetic acid. 1 tab.

Description

one

The invention relates to the chemistry of high-molecular compounds, specifically to the preparation of crosslinked copolymers of acrylic acid or acrylic acid and acrylamide, which have an increased water-retaining and thickening ability, which can be used in garden and agriculture to create means that retain water for a long time in soil and improve its structure soil, in medicine as a basis for the preparation of physiological and sanitary napkins, in the paint and varnish industry for thickening in, in the pharmaceutical industry for the preparation of creams and pastes, as well as compositions for extinguishing ingredient, as a dehydrating agent, etc.

The purpose of the invention is to increase water holding with a high level of thickening ability.

Acrylamide (DAM) CH2 CH-CONH2 5 polyacrylamide (PAAM) is a polymer with the formula

Ј CH - CHJ

Uz | -J P

CONH2

acrylic acid (AK) - CH2 CI-COOH {polyacrylic acid (PAA) - polymer with the formula of Even

{CH2-CH.J,

I soon

water-soluble allylcarboxymethylcellulose (ACMC) r - Aormyou link

{C6H702 (OH) v- (0-CH2 COONa} -2 - 0-CH2-CH CH2) L

where x is the degree of substitution by carboxyl groups is 0.60-0.76;

y — the degree of substitution in the allyl groups is 0.05-0.40; p - the degree of polymerization SP,

equal to 400-500,

water soluble allyloxyethylcellulose (AOEC) with the formula of the link

{

s & h7o2 (he) o-ch2 sn2on) h- (o-cng-sn

SNL} P

where x is the degree of substitution by hydroxyethyl groups, is equal to. 0.5-2.0;

y, the degree of substitution in the allyl groups is 0.05-0.40;

n - the degree of polymerization, equal to 1000-1200,

water soluble apyloxypropylcellulose (AOC) with the formula

CH

s6n7o2 (he) 3.- (o-sn2-sn x - o-sn2-sn

he

-

x

The degree of substitution by hydroxypropyl groups is 1.45-2.50; the degree of substitution in allylic groups is 0.05-0.40;

n - the degree of polymerization, equal to 175-324,

water soluble allymethylcellulose (AMC) with the formula link

{с6н7о2 (he) з - (o-cHj-ci

-.} „

where x is the degree of substitution in methyl groups equal to 1.0-2.0;

y - the degree of substitution by allyl groups is 0.05-0.35 ;.

n - the degree of polymerization, equal to 1000-1200,

water soluble allyl sulfoethylcellulose (AECC) with the formula of the link

0

J

five

0

five

0

five

0

five

С6Н 702 (ОН),.,. ОННг СН2 S03 Na tusser) Лъ

where x is the degree of substitution by sulfoethyl groups is 0.5-1.35;

y — the degree of substitution in the allyl groups is 0.06-0.30;

n - degree of polymerization, equal to 200-400.

The method is carried out as follows.

Radical copolymerization of AK or AK and AAM is carried out with a cross-linking polyfunctional reagent. As the latter, water-soluble allyl ether of cellulose derivatives from the series including AKMC, AOEC, AOFC, AC, AECC with a degree of substitution on allyl groups of 0.30- is taken. 0.40, the concentration of agshyl ether 0.05-0.12 May., The total concentration of (co) monomers 25-35 wt.%.

The polymerization is carried out in aqueous solutions in the presence of atmospheric oxygen when initiated by a catalyst obtained by electrolytic oxidation of divalent cobalt acetate in concentrated acetic acid. The concentration of the catalyst in the polymerized mixture (0.30-1.00) mol / l Co (III).

The synthesized copolymers are characterized by the degree of equilibrium swelling (water retention) in distilled water and in 1% aqueous NaCl solution.

Deformation and strength properties of the swollen polymer are determined at

uniaxial compression of the samples maximally swollen in water. The viscosities of 0.25 and 0.10% dispersions obtained by swelling dry polymers of powders with a particle size of 125 to 250 µm are measured.

The deformation-strength characteristics of hydrogels are given for comparison with known data, since the strengths of hydrogels determine, in a number of cases, the effectiveness of their practical use. To determine the deformation-strength characteristics, the maximum swollen polymer gel is cut into cylindrical samples with a diameter of 20-50 mm and a height of 20-30 mm. The value of compressive strength (30 calculated on the initial sample cross-sectional area and the value of the Young's modulus E is determined from the uniaxial compression diagrams obtained at 1- & 295 K on a universal tensile machine with a traverse speed of 5 mm / min. dried copolymer, with a particle size of 1-2 mm. A portion of 0.1 g of this fraction is poured into 1 liter of distilled water. A portion of 0.50 g is poured into 200 ml of 1% aqueous NaCi solution with stirring. After 24 hours, the gel is separated from phase of the water phase. Is defined as the ratio of the masses of the swollen gel in g per 1 g of dry copolymer.

The viscosities of the swollen polymer dispersions are determined on a rotary viscometer using a cylindrical measuring device, shear rates X1,12, and t - 20 ° C. °

Measurements of the 0.10- and 0.25% dispersions of the said copolymer are also carried out under similar conditions.

Ix

According to the basic method, viscosity measurements are carried out on a Brookfield viscometer, which is characterized by a dependence not only on the speed of rotation, but also on the number of the spindle used. When the dispersion concentration changes, it becomes necessary to change the spindle, which makes the results incomparable. In this regard, the use of a Reotest type viscometer is more appropriate.

812366

Example 1. Synthesis of a copolymer based on AK. To 3 g of freshly distilled AA in vacuum, was added 4.2 ml of 8 M NaOH solution, thus neutralizing with 80% AA. To the mixture was added 2.4 ml of water, 0.50 ml of a 1% aqueous solution of ACMC with a degree of substitution in the allyl group of Pam 0.40, a degree of substitution in kar-. bauxomethyl groups 0.76, polymerization band 400, 0, P5 ml of a Co (III) solution in concentrated acetic acid are added with stirring.

The reaction mixture with a total volume of 10 ml contains 30% by weight of AA, 0.05% by weight of AKSH and 0.63-KG3 mol / l Co (III). Mixture is poured into three about 20 tags (f5 mm, height 180 mm).

The tubes are placed in a thermostat and heated at 50 ° C for 5 hours. Induction period 15 mn. Polymerization is carried out in the presence of oxygen.

25 air. After the completion of the reaction, the gel is removed by the test tubes and a part (1/3) of the gel is placed in water to determine the deformation and strength characteristics.

30 To the remaining gel is added

50 ml of water and ground with stirring. After 30 minutes, the water-soaked gel is filled with an excess of acetone (30 ml). Sediment sugat in vacuum

35 over P20f at 20 ° C.

The polymer has a moisture content of 3300 g / g in water and 153 g / g in 1% NaCl solution. Compressive strength 1.6 kPa, mod. No. of lo E 2.0 kPa.

40 Viscosity of aqueous 0.25- and 0.10% dispersions of 5920 and 2220 mP-s (spP), respectively. Examples 2-П and 16-21 are made under conditions of example I and are presented in the table.

45

Example 14. Synthesis of crosslinked

copolymer based on AK and AAM.

To 1.5 g of AK, 2.1 ml of 8 M NaOH are added and thus neutralized.

-80% AK.

2.75 ml of a 55% acrylamide solution in water are added to the mixture, then 0.50 ml of a 1% solution of allylcarboxymethylcellulose with a degree of 0.40 substituted by allyl groups, and a carboxymethyl substitution degree groups of 0.76 and a degree of polymerization of 400, after which 2.5 ml of water and 0.05 ml of solution are poured

pa Co (III) in concentrated acetic acid.

The reaction mixture with a total volume of 10 ml contains 15 mol.% AA, 15 wt.% 5 DAM, 0.05 wt.% AKMC and 0 mol / l Co (III).

The polymerization and the subsequent operations are carried out under the conditions of Example 1.

Examples 12-15. Completed under the conditions of example 14 and presented in the table.

Example 23. Getting the initiator.

40.16 g Co () g - 4H2015

(0.185 mol) is dissolved in concentrated IP of UNA, while the total volume of the solution is 500 ml with a concentration of 0.37 mol / l.

The resulting solution is poured

an electrolytic cell, which is a ceramic cup with an inner diameter of 125 mm, in which a ceramic porous cup with an outer diameter of 120 mm and an inner 100 mm is placed; Height of glasses is 170 mm. The porous glass in the lower part of the outer diameter is covered by a cathode made of copper foil with a thickness of 0.2 mm and a width of e®

50 mm. The cylindrical anode with a diameter of 80 mm and a width of 50 mm is made of platinum foil with a thickness of 0.15 mm and placed inside a porous glass.

A solution of cobalt diacetate is poured into a porous ceramic beaker. At the same time, the solution fills the volume between the glasses. The electrolysis is carried out at a current density of 200 A / m (5A) and a temperature of 20 C to the maximum attainable Co (III) concentration (20 h).

The concentration of Co (III) is monitored spectrophotometrically according to the concentration of Te (III) obtained by adding an excess of FedD 45 solution to the electrolyzate. (2.88 + 0.03) - 10E

The target product obtained by electrolysis contains 0.16 mol / l Co (III) and 0.21 mol / l Co (I) in a concentrated solution. The electrolysis product is stable when stored for a long time.

five

five

0

®

50

five

l about rm at l. the invention

The method of obtaining copolymers with a water-holding and thickening ability by radical copolymerization of acrylic acid or acrylic acid with acrylamine and a cross-linking polyfunctional reagent in an aqueous medium, is different from the fact that, in order to increase water retention at a high level of thickening ability, use a concentration of (co) monomers of 25- 35 wt.%, as the initiator use the reaction mixture obtained by electrolytic oxidation of bivalent cobalt acetate in concentrated acetic acid when the content in the polymerized mixture of cobalt (III) (0.30-1.00) is 10 mol / l, and the reaction mixture is the product of the electrolytic oxidation of cobalt (II) acetate in concentrated acetic acid, and as a cross-linking polyfunctional of the i reagent, 0.05-0.12 wt.% of the reaction mixture of the compound selected from the group consisting of allylcarboxymethylcellulose with a degree of substitution in allylic groups of 0.40, and a degree of substitution in carboxymethyl groups of 0.60-0 are used. , 76 and polymerization degree 400-500, allyloxyethylcellulose with heat of substitution in allyl groups of 0.35, degree of substitution in hydroxyethyl groups of 1.2 and degree of polymerization of 1100, allkshxypropylcellulose with a degree of substitution in allyl groups of 0.40, degree of substitution in hydroxypropyl groups of 2.0 and degree of polymerization 320, allyl methylcellulose with a degree of substitution in the allyl groups of 0.35, a degree of substitution in the methyl groups of 2.0 and a degree of polymerization of 1100, allyl sulfoethyl cellulose with a degree of substitution in the allyl groups of 0.30, a degree of substitution in the sulfoethyl groups of 1.2 and a degree olimerizatsii 400.

Claims (1)

Claim A method of producing copolymers with a water-holding and thickening ability by radical copolymerization of acrylic acid or acrylic acid with acrylamine and a cross-linking multifunctional reagent in an aqueous medium, characterized in that, in order to increase water retention at a high level of thickening ability, a concentration of (co) monomers of 2535 wt. %, the reaction mixture obtained by electrolytic oxidation of cobalt acetate in concentrated acetic acid at keeping cobalt (III) (0.30-1.00) · 10 ' ³ mol / l in the polymerized mixture, and as a reaction mixture the product of electrolytic oxidation of cobalt (II) acetate in concentrated acetic acid, and as a cross-linking multifunctional reagent 0.05 0.12% by weight of the reaction mixture of a compound selected from the group consisting of allyl carboxymethyl celluloe with a degree of substitution of allyl groups of 0.40, a degree of substitution of carboxymethyl groups of .0,600.76 and a degree of polymerization of 400,500, allyloxyethyl cellulose with a degree of substitution are used I for allyl groups 0.35, degree of substitution for hydroxyethyl groups 1.2 and degree of polymerization 1100, allyloxypropyl cellulose with degree of substitution for allyl groups 0.40, degree of substitution for hydroxypropyl groups 2.0 and degree of polymerization 320, allylmethyl cellulose with degree of substitution for allyl groups of 0.35, a degree of substitution for methyl groups of 2.0 and a degree of polymerization of 1100, allyl sulfoethyl cellulose with a degree of substitution of allyl groups of 0.30, a degree of substitution of sulfoethyl groups of 1.2 and a degree of polymerization of 400. G * " Hhh <P w with w cho ah Joint venture CHG 0 tn tn <P Joint venture tn 40 about about Ό <P 43 <n tn tn tn * 0 mid 40 about tn tn tn 40 tn <A in 40 tn with A • * A • A A A A A A A A mid mid sch mid <h mid mid mid mid mid Joint venture mid mid mid mid mid mid mid mid mid 40 about ° 2 about about about about about about about about about about about about about about about about about cm cc about about Joint venture Joint venture 40 04 about AM 40 cn 0 mid with g * about mid tn * 0 about mid g * o ACh 1O σ \ <P 40 tn 04 AN mid 04 mid 04 40 cho mid Joint venture η mid - Joint venture w mid mid mid m Joint venture mid Joint venture mid AM Joint venture Joint venture 40 about about about about about about about from about about Q about from about I'm about about about 0 40 Joint venture 40 r> about about g * 0 about 10 about about about mid tn about g- cn Joint venture 00 0 04 w 40 gh 04 00 with 40 g * - .0 tn tn * 0 cn and oo with cp • m ** · “ ** g *. Joint venture ** 40 · - · with ~ 40 mid Joint venture 0 to * - 1 X 1 <0 about. A X "s a: X X Ϊ h ABOUT) Oh x 2 * and from with £ S l 'slowness is small to measure