JPS5815491B2 - Powdered cationic polymer electrolyte based on acrylamide and quaternized or chlorinated dimethylaminoethyl acrylate and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to acrylamide and quaternized or salt-forming (s)
The present invention relates to a powdered cationic polymer electrolyte based on dimethylaminoethyl acrylate and a method for producing the same.

Pollution, anti-pollution campaign The treatment of municipal wastewater at purification stations within the area produces muds, which are advantageously dewatered in preparation for their landfilling or incineration.

This dewatering is essentially done by p-filtration or centrifugation and requires the addition of flocculants to the sludge, either mineral materials (aluminum sulfate, ferric chloride) or organic materials (polyelectrolytes). It is said that

Mineral flocculants have several drawbacks, among them the often improper formation of agglomerates and the low mechanical strength of the agglomerates which makes these flocculants useless for centrifugation. , may have residual turbidity, and may require large doses to be used.

Also, organic flocculants, ie, polyelectrolytes, especially high molecular weight water-soluble synthetic polymers, are becoming increasingly preferred.

The latter include nonionic, anionic, and cationic types.

It is generally accepted that cationic polyelectrolytes are the only ones capable of flocculating sludge derived from municipal wastewater.

Among cationic polyelectrolytes, copolymers of acrylamide and cationic monomers are highly recommended, especially copolymers of acrylamide and quaternized or salt-formed aminoalkyl acrylates or methacrylates. ing.

In fact, the patent literature provides many formulas for copolymers of this type, but the examples are very limited to copolymers of acrylamide and quaternized or salt-formed aminoalkyl methacrylates.

In fact, it is difficult to find aminoalkyl acrylates on the market.

The only one that has been proposed is diethylaminoethyl acrylate, which has the disadvantage that acrylates are generally much more sensitive to hydrolysis than methacrylates, so it is difficult to copolymerize them in aqueous media.

It is an object of the present invention to provide an improved water-soluble cationic polyelectrolyte in powder form so as to minimize the above-mentioned disadvantages.

Another object of the present invention is to provide a method for producing such an improved cationic polymer electrolyte.

Other objects and advantages of the invention will become apparent from the description below.

Intrinsic viscosity and cationicity
It is here that the copolymer of acrylamide and quaternized or salt-formed dimethylamine ethyl acrylate is significantly superior to acrylamide and quaternized or salt-formed amino alcohol methacrylate. Therefore, they were found to be excellent flocculants for the treatment of municipal sludge.

The cationic water-soluble polyelectrolytes in powder form according to the invention contain acrylamide and quaternized or salt-formed cationic units with a molar ratio of 10 to 50% regularly distributed in the copolymer territory. It is characterized by being composed of a copolymer of dimethylaminoethyl acrylate, and having an intrinsic viscosity of more than 6 dl/g and a measured cationic degree greater than the 90th factor of the theoretical cationic degree, and is expressed by the following formula: In the formula, R represents a hydrogen atom or an alkyl group, X○ represents an anion, and mi, ni and pl are ml, m2.
m3………………m1 nl, n2. n3......n1 pl, p2. p3......represents integers that are the same or have little difference taken from the system of pi, where .

The dimethylamine ethyl acrylate used can be obtained, for example, by reacting ethyl acrylate with dimethylaminoethanol in the presence of an alkyl titanate (
(U.S. Pat. No. 2,822,348).

Quaternization is carried out in known manner with dimethyl sulfate or methyl chloride or any other alkyl halide.

Salt formation is carried out by the action of a strong mineral acid, preferably hydrochloric acid.

By this method, the following cationic monomers are obtained.

CH2=CH-C00CH2-CH2-N+(CH3)
3°SO*CH3- or MSA.

CH2=CH-C00CH2-CH2-N+(CH3)
3°C1-i.e. CMA.

CH2=CH-C00H-CH2CH2-N1H(CH
3) 2°C1 - ie CAH.

Hereinafter, the percentage proportions of each monomer in a mixture or copolymer are always expressed in molar units;
A copolymer obtained from 0% acrylamide (AAM) and 30% MSA is designated as 70/30 AAM/MSA.

When quaternized or salt-formed dimethylamine ethyl acrylate or methacrylate is copolymerized with acrylamide, two different methods are used to demonstrate that the difference lies in the regularity of the alternation of the cationic units in the chain. (
Vyskmol, 5oyed A11(8), 1670
(1969) A, 1. Yezr-ielev, E, L
J, Am, Chem, Soc, 66J9, modified by , Brokhina and Y, E, Roskin.
44 F, R, Mayo and F, M, Lewis method and J, Polm, sci, 5259 (1950
acrylamide/methyl chloride quaternized dimethylaminoethyl acrylate (AAM/CMA) and acrylamide/dimethyl sulfate quaternized dimethylaminoethyl methacrylate (AAM /MSM) reactivity ratios r1 and r2 were determined for the pair.

The following values were obtained.

Pair AAM/CMA r1=0.72 r2=0.66 Pair AAM/MSM r1=o, 23 r2-2.15 Here, for Pair AAM/CMA, rl and r2 are smaller than 1 and approximate. It can be seen that a more regular alternating distribution of cationic units along the chain is obtained using this pair than when using the pair AAM/MSM where rl is less than 1 and r2 is more than 1. It is estimated that there is no.

Experiments have shown that for mixtures of monomers of various compositions of the two above-mentioned pairs, the average deviation and conversion ratio function of the copolymer is calculated for the copolymer with respect to the composition of the mixture of monomers. A composition curve was established.

The results are shown in the table below. . Here, it is well established that in the case of the pair AAM/CMA, the composition of the copolymer deviates less from the initial composition of the monomer mixture than in the case of the pair AAM/MSM.

Therefore, the copolymer obtained from the pair AAM/CMA is;
It has a more regular distribution of cationic units than the copolymers obtained from AM/MSM.

To illustrate the difference, an AAM/MSM copolymer obtained from a monomer mixture with 10% MSM has 36 chains of it containing less than 2% cationic units, whereas the corresponding AAM/CMA copolymer has cationic units 2
It has only one section of its chain containing less than %.

The copolymers according to the invention always have both an intrinsic viscosity greater than 6 dl/g and a measured cationic degree greater than 90% of the theoretical cationicity, as shown below, the corresponding acrylamide/quaternized or chlorinated dimethylaminoethyl methacrylate. Copolymers do not have these two properties at the same time.

Regarding the intrinsic viscosity [η], the latter is measured in a 1 molar solution of NaCl at 30° C. by a conventional method.

Further, the theoretical degree of cation of a copolymer is expressed by the number of milliequivalents of cations theoretically present in the copolymer per gram of the copolymer.

For a copolymer of x moles of acrylamide having a molecular weight A and y moles of a cationic monomer having a molecular weight B, that is, for a copolymer in which the average molecular weight M of the unit is , the theoretical cation degree is given by:

The measured cationicity of the copolymers according to the invention [Barry City, Masson and Cie eds., J.A.

Gautier and P. Malangeau, Mi
seau point de chimie anal
ytique organi-que, pharmac
eutique et bromatologiq-u
17, page 83 of the anionic surfactant sodium dioctyl sulfosuccinate in a buffered water-chloroform medium in the presence of methyl yellow.
．． It is measured by a method consisting of quantifying cationic units in a 004M aqueous solution.

The measured cationic degree is expressed in milliequivalents/g.

The copolymers according to the invention always have a measured cationicity very close to the theoretical cationicity, whereas the corresponding copolymers with methacrylates instead of acrylates have a high content of cationic units. only has a measured cationicity close to the theoretical cationicity.

The measured cationicity, which is close to the theoretical cationicity, indicates a good distribution of the cationic units along the chain; in fact, when the cationic units are divided into groups instead of being regularly distributed, the chain is The system units have a tendency to form clusters which are not achieved by the analytical reaction components and no longer properly fulfill their role.

The table below shows MSM, CMM (methacrylate of dimethylamine ethyl quaternized with methyl chloride), CMA or C
The values of intrinsic viscosity [η], theoretical cationic degree, and measured cationic degree are shown for several copolymers based on HA (acrylate of dimethylamine ethyl salt-formed with HCI).

The copolymers according to the invention have both an intrinsic viscosity greater than 6 dl/9 and a measured cationicity greater than 90% of the theoretical cationicity, which is not the same for copolymers containing methacrylates. The results are indeed clear and demonstrate the good results obtained with the copolymers according to the invention in the treatment of municipal sludge.

These results were established by two tests: the agglutination test and the p excess test.

The first test is to flocculate the sludge by stirring with a certain amount of polyelectrolyte and to measure the half-decantation time, i.e., the decantation section until half of the initial total height of the slurry or sludge is reached. It consists of measuring the time to take out half of the

This test, in which sludge from the Ashle purification station at Barrie City Center was 8 g/l and each polymer was used at a rate of 2 ky/l (2 kg per ton of dry sludge), gave the following results in terms of half-decantation time: was gotten.

AAM/CHA-70/30 22 seconds AAM/CHE-70/30 58 seconds AA, M/MSM-70/30 8 minutes 30 seconds AAM/C
MA-80/20 45 seconds AA, M/CMM-80/20 4 minutes 30 seconds (OHE=
Acrylate of diethylamine ethyl salt formed with HC1) The clear superiority of the cohesive strength of the products according to the invention over the corresponding products based on diethylamine ethyl acrylate or methacrylate can be seen.

The second test consists of measuring the capillary suction time of the flocculated sludge, which can be related to the resistivity of the sludge to filtration.

The device, handcrafted by Triton Electric, consists of a filtration tank with a hollow metal cylinder covered with Whatman No. 17P paper and a recording device, each with a radius of 32 mm.
and the migration time of the aqueous phase (after filling the cylinder with flocculated sludge) between two circles marked on a 45 mm filter can be measured.

Polyelectrolyte according to the invention and comparative polyelectrolyte 4k
The comparative results for Asure sludge at 8 g/l containing g/l are shown in the table below, expressed in seconds.

AAM/CHE-80/20399 seconds AAM/CHA-80/2028 seconds AAM/CHE-70/30364 seconds AAM/MSM-70/30163 seconds AAM/MSA-70/3049 seconds AAM/CMA-70/3021 seconds AAM/ CHA-70/3030 seconds There is a very clear superiority for the copolymer according to the invention over both the copolymer based on dimethylamine ethyl methacrylate and the copolymer based on diethylaminoethyl acrylate. It was observed that

Polyelectrolytes according to the invention are therefore particularly suitable for use in the flocculation of municipal sludge.

They range from 1 to 1 ton of dried sludge depending on the type of sludge.
Can be used at a rate of 5 kg.

As mentioned above, dimethylaminoethyl acrylate can be hydrolyzed much more easily than the corresponding methacrylate.

By simply dissolving these products in water giving a solution pH of around 11, at 20°C the methacrylates are very little hydrolyzed (6 parts in 30 minutes), while in the same time the acrylates are 50% hydrolyzed. do.

At pH 5.5-6, the hydrolysis of acrylate is very small, in 1 hour it is 0.8% at 40°C and 3.0% at 60°C.
8, but it is still 4 times the speed of methacrylate.
~5 times faster.

Therefore, there is a problem in controlling the copolymerization of quaternized or salt-formed dimethylaminoethyl acrylate, especially in order to obtain a powdered polymer.

It is relatively easy to obtain copolymers of acrylamide and quaternized or salt-formed dimethylamine ethyl acrylate in the form of solutions in water by carrying out the copolymerization at suitable pH, but thus even at low concentrations A gel is obtained which is almost impossible to convert into powder.

For industrial use, it is preferred for polyelectrolytes to be in powder form, which is easier to transport and cheaper than aqueous solutions.

The invention therefore also includes an advantageous method for producing the polyelectrolyte according to the invention in powder form.

According to an advantageous method for producing polyelectrolytes in powder form according to the invention, the copolymerization of the monomers takes place at a pH of 3 to 6.
, preferably from 4.5 to 6, using an initiator, in an inverted water-in-oil emulsion (i.e. in water in the presence of a water-immiscible organic solvent), and then at temperatures below 80°C to avoid hydrolysis. Dehydration is carried out at temperature.

Dehydration is carried out, when a solvent is available, by azeotropic distillation of the water with said solvent to a moisture content of not less than 10 parts, followed by drying in a fluidized bed at a temperature below 75°C.

If the solvent does not allow azeotropic dehydration, the copolymer can be separated by decanting and washed with a solvent such as acetone before drying.

The organic solvent for polymerization used is hebutane, branched CIO to C1
A mixture of two aliphatic hydrocarbons or an aliphatic or cyclic hydrocarbon such as cyclohexane.

Heptane and cyclohexane are preferred because they enable azeotropic dehydration of the copolymer.

The concentration of monomers in the aqueous phase can vary from 40 to 70% and, as mentioned above, the monomer mixture can contain from 10 to 50 parts of cationic monomerity, expressed in moles.

As initiators, customary initiation systems such as photoinitiators in the presence of light, azo compounds, peroxides, organic hydroperoxides (benzoyl peroxide, cumene hydroperoxide) and alkali persulfates, alone or in combination, can be used. It can be used as

These include tertiary amines (dimethyl paratoluidine, triethanolamine) as activators, organic salts and complex salts of transition metals (cobalt (■) octoate, iron (1) acetylacetonate), sulfites, thiosulfates and alkali Can be used with metabisulfite etc.

The emulsifier used is essentially of low HLB (hydrophilic-lipophilic balance) and is preferably a fatty acid ester of sorbitan, such as sorbitan monooleate.

The following examples are given for illustrative purposes only and should not be considered as limiting the invention.

Example 1 A solution of 4.29 kg of sorbitan monooleate in 409 ky cyclohexane was placed in an 80/20-AAM/CMA copolymer reaction vessel, then the air was evacuated, nitrogen was added, and the temperature was heated to 20° C. without stirring. So 127
．． 4 kg acrylamide and 86.8 kg CMA
(acrylate of dimethylaminoethyl quaternized with methyl chloride) was charged and the pH was brought to 5 with 20% ammonia to form an emulsion.

Heat to 30 °C with exclusion of air through nitrogen and then add an initiator mixture consisting of 91.8 y of 70% cumene hydroperoxide in 21 g of cyclohexane and 406.5 g of iron acetylacetonate in 61 g of acetone. Introduced.

It was then gradually heated until polymerization started, and then the reaction was allowed to continue until boiling under reflux.

6.4 in 5 kg of cyclohexane at 45°C
A solution of 3 kg of sorbitan monooleate was introduced.

It was kept at boiling point for 1 hour and then the water was removed by azeotropic distillation.

When the water content of the solid was close to 10 parts, it was cooled, drained, and drying was completed in a fluidized bed at 75°C, which was sieved and ground.

In this way a granular product of less than 1 mm was obtained with a dry extractability of 96%.

A 1% aqueous solution was measured at 20°C using a Brookfield RVT viscometer.
It had a viscosity of 3000 cp as measured at .

The intrinsic viscosity [η] at 30°C in a 11 molar NaC solution is 7.
．． 2 dl/g, and the measured cationic degree was 2.0, that is, 96 times the theoretical cationic degree.

Example 2 An 88/12-AAM/CMA copolymer reaction vessel was charged with a solution of 3.61 kg of sorbitan monooleate in 467 kg of cyclohexane, evacuated of air, and charged with nitrogen, followed by a solution of 3.61 kg of sorbitan monooleate in 220 kg of deionized water. 48.
A solution of 76 kg of CMA and 131.3 kg of acrylamide adjusted to pH 4.4 was charged.

This was brought to 30°C and then 77.1 g of 70% cumene hydroperoxide of 21 and F of 61
e(■) A mixture of 341.6 g of acetylacetonate was added.

This was heated gradually, and as soon as polymerization started, heating was stopped and the temperature was allowed to rise.

At 60° C. 5.42 kg of sorbitan monooleate in 5 kg of cyclohexane were added.

After boiling and refluxing, the mixture was kept at 70 to 72°C for 1 hour, and then cyclohexane was added to maintain a sufficient volume in the reaction vessel, and water was dehydrated by azeotropic distillation.

Distillation was stopped when approximately 188 kg of water had been removed, ie, when the copolymer still contained 15 parts of water.

It was then cooled, drained, dried in a fluidized bed at 70°C, sieved and ground.

The product obtained had a particle size of less than 1 mm, and its dry extract was 97 mm.

The viscosity of a 1% solution in distilled water was 2000 cp at 20°C.

The intrinsic viscosity [η] at 30°C in a 1 molar solution of NaCl is 7
．． 6 dl/g, and the measured degree of cation was 1.5, ie 107% of theory.

Example 3 70/30 and 50150-AAM/CMA Copolymers Using the same procedure as Example 1, C
A copolymer containing MA 30% and 50% was made.

The product obtained had the following properties.

70/30-AAM/CMA copolymer: The viscosity of a monochrome solution at 20°C is 2900 Cp.

50150-AAM/CMA copolymer: The viscosity of a monochrome solution at 20°C is 3300 Cp.

(Intrinsic viscosity [η)>6ax/g).

Example 4 The procedure of Example 1 was carried out for copolymerization using an acrylamide/HCI salted dimethylamine ethyl acrylate (CHA) mixture.

The following products were obtained depending on the molar ratio of CHA.

Example 5 80/20-AAM/CMA and AAM/CMM Copolymers To a solution of 22 g of sorbitan monooleate in 820 g of cyclohexane is added a solution of 255 g of acrylamide and 1749 CMA with stirring under nitrogen. Ta.

After passing nitrogen through for 30 minutes, 313 m9 of iron (■) acetylacetonate dissolved in 5 m6 of acetone and 184 mg of 70 cumene hydroperoxide were introduced at 30°C.

After a few minutes the temperature rose to 70°C.

After 1 hour at this temperature, water was removed by azeotropic distillation.

When 480g of water is harvested annually, separate it into a furnace and boil it for 30 minutes at 80
After drying with pulsating air at 0.degree. C., the product obtained was ground and sieved.

The viscosity of a 1% solution of this product was 3750 cp at 20° C. and [η] was >6 dI/g.

The measured cationic degree was 20 meq/g, which was 96 times the theoretical cationic degree.

The half-decant time for Ashle sludge at 89/l containing 2ky/l of product was 45 seconds.

CMA is replaced by CMM to obtain the same molar proportion of monomers, i.e. 2
Tests were conducted under the same conditions using 48 g of acrylamide and 181 g of CMM.

The viscosity of a solution of the obtained product in water at 20°C is 65
0 cp, the measured cation degree is 1.3 meq/g,
That is, it was 64% of the theoretical cation degree.

The half-decantation time for Ashle sludge containing 2 kg/l product was 4 minutes 30 seconds at 8 g/l.

Substitution of acrylate with methacrylate resulted in very low viscosity and cationicity and very long half-decantation time.

Example 6 To a solution of 21.5 g of sorbicun monooleate in 1060 g of a C1o-01□ branched hydrocarbon mixture stirred under a nitrogen atmosphere was added a solution of 116 g of CMA and 313 g of acrylamide (cationic) in 524y of water. A monomer mixture containing 12 moles of monomer was added.

This was heated to 30°C, and 184 kg of Cumenhide D Kei-oxide of 70 and 813 mg of Kessaku acetylacetonate dissolved in 5 ml of acetone were introduced. Heating was stopped immediately after the polymerization started, and the temperature was kept at 70°C. and then held at this temperature for 1 hour.

After cooling, the copolymer was precipitated, the organic solvent was removed, and the copolymer particles were washed twice by shaking with 11 acetone;
Filtered, dried at 80° C. for 1 hour, ground and sieved, the resulting product had a measured cation group of 1.6 meq/g.
, that is, 114% of the theoretical cation group.

Copolymerization was carried out under the same conditions using 252 g of acrylamide and 177 g of MSM (ie, 15 parts of cationic monomer).

The product obtained had a measured cation family of 0.9 meq/g (62% of the theoretical cation family).

Finally 283g acrylamide and 146g CM
M (i.e., a cationic monomer with a coefficient of 15) and copolymerized under the same conditions to obtain 0.9 meq/g (theoretical coefficient of 55).
A product with a measured cation group of .

Therefore, the copolymer using the 15 methacrylate had a significantly smaller cationic group than the cationic group of the copolymer according to the invention, which used only 12% of cationic monomer.

Claims (1)

[Claims] - Formula 1 (in the formula, R represents a hydrogen atom or an alkyl group, XO represents an anion, mi, ni and pi are ml, m2
．． m3………………m1 nl, n2. n3......n1 pl, p2. p3 represents the same or very similar integers taken from the system of pi, where Quaternized or chlorinated dimethyl containing 10 to 50% molar proportion of cationic units regularly distributed along the copolymer silver, having an intrinsic viscosity of more than 6 dl/g when measured in A water-soluble powdered cationic polyelectrolyte that can be used to flocculate municipal sludge, consisting of a copolymer of aminoethyl acrylate and acrylamide. 2. The polymer electrolyte according to claim 1, wherein dimethylamine ethyl acrylate is quaternized with a quaternizing agent selected from the group consisting of dimethyl sulfate and methyl chloride. 3. The polymer electrolyte according to claim 1, wherein dimethylamine ethyl acrylate is salt-formed with hydrochloric acid. 4 pH 3 in the presence of a water-immiscible organic solvent and an initiator.
~6, in the form of an inverted water-in-oil emulsion, copolymerizing acrylamide with quaternized or salt-forming dimethylaminoethyl acrylate, and dehydrating it at a temperature of 80°C or less (in the formula R represents a hydrogen atom or an alkyl group, Xe represents an anion, mi, ni
and pi is ml, m2. m3......field...m1 nl, n2. n3......n1 p12p2. p3 represents the same or almost similar integers taken from the system of pi, with the proviso that the measured cationicity is greater than the 90th factor of the theoretical cationicity and in a 1 molar solution of sodium chloride. A quaternized or salt-forming dimethylamino acid having an intrinsic viscosity of more than 6 dl/g when measured at A method for producing an aqueous powder cationic polymer electrolyte consisting of a copolymer of ethyl acrylate and acrylamide. 5. The method of claim 4, wherein the copolymerization is carried out at a pH of 4.5 to 6. 6. The method of claim 4, wherein the oil phase is constituted by a hydrocarbon selected from the group consisting of aliphatic hydrocarbons and cyclic hydrocarbons. 7. The method of claim 6, wherein the oil phase is comprised of hebutane or cyclohexane. 8. The method according to claim 6, wherein the dehydration is carried out by azeotropic distillation of water so that the water content of the copolymer does not become less than 10%, and the drying is completed in a fluidized bed at a temperature of 75° C. or lower. .