POLYMER OF 2-ACRYLAMIDO-2-METHYLPROPANE SULFONIC ACID OR THE SALTS THEREOF

Abstract

The present invention relates to a polymer obtained at least from a quantity A of 2-acrylamido-2-methylpropane sulfonic acid, in acid and/or salified form, characterized in that the quantity A of 2-acrylamido-2-methylpropane sulfonic acid contains 250 to 20,000 ppm by weight of 2-methyl-2-propenyl-sulfonic acid, in acid and/or salified form. The present invention also relates to the use of this polymer as a flocculant, viscosity reducing agent, thickener, absorbent, friction reducing agent or plasticizer or superplasticizer, in particular in a field chosen from among oil and gas recovery, water treatment, sludge treatment, paper manufacture, construction, mining, cosmetic product formulation, detergent formulation, textile manufacture and agriculture.

Claims

1. A polymer obtained at least from a quantity A of 2-acrylamido-2-methylpropane sulfonic acid, in acid and/or salified form, characterized in that quantity A of 2-acrylamido-2-methylpropane acid sulfonic acid contains 250 to 20,000 ppm by weight of 2-methyl-2-propenyl-sulfonic acid, in acid and/or salified form.

2. The polymer according to claim 1, characterized in that quantity A of 2-acrylamido-2-methylpropane sulfonic acid, in acid and/or salified form, contains 300 to 20,000 ppm of 2-methyl-2-propenyl-sulfonic, in acid and/or salified form.

3. The polymer according to claim 1, characterized in that quantity A of 2-acrylamido-2-methylpropanesulfonic acid, in acid and/or salified form, contains 300 to 10,000 ppm of 2-methyl-2-propenylsulfonic acid, in acid and/or salified form.

4. The polymer according to claim 1, characterized in that the polymer is further obtained from a quantity B of 2-acrylamido-2-methylpropane sulfonic acid, in acid and/or salified form, containing strictly less than 200 ppm by weight of 2-methyl-2-propenyl sulfonic acid, in acid and/or salified form.

5. The polymer according to claim 1, characterized in that the polymer is a water-soluble polymer or a superabsorbent polymer.

6. The polymer according to claim 1, characterized in that the polymer is water-soluble and has a weight-average molecular weight greater than 100,000 g/mol and less than or equal to 40 million g/mol.

7. The polymer according to claim 1, characterized in that the polymer is a homopolymer of 2-acrylamido-2-methylpropane sulfonic acid, in acid and/or salified form, or a copolymer of 2-acrylamido-2-methylpropane sulfonic acid, in acid and/or salified form, further comprising at least one monomer chosen from the group comprising nonionic monomers, anionic monomers, cationic monomers, zwitterionic monomers, and mixtures thereof.

8. The polymer according to claim 1, characterized in that the polymer is obtained at least from 2-acrylamido-2-methylpropane sulfonic acid, in acid and/or salified form, the total quantity of which contains strictly less than 20,000 ppm by weight of 2-methyl-2-propenyl sulfonic acid, in acid and/or salified form.

9. The polymer according to claim 1, characterized in that the polymer is water-soluble and in that the proportion D of quantity A relative to the total quantity of 2-acrylamido-2-methylpropane sulfonic acid, in acid and/or salified form, is determined from the ratio R defined according to the following equation (1): $\begin{array}{cc}R=\frac{{10}^{14}}{{\left[\mathrm{IBSA}\right]}^2*C^2\mathrm{Mw}}& \left(1\right)\end{array}$ wherein, [IBSA] is the concentration in ppm by weight in quantity A of 2-methyl-2-propenyl-1-sulfonic acid; Mw is the weight-average molecular weight of the polymer expressed in g/mol; C is a coefficient equal to 0.2 when Mw is less than or equal to 1 million, equal to 0.6 when Mw is strictly greater than 1 million and less than or equal to 10 million, and equal to 0.8 when Mw is strictly greater than 10 million; when R is strictly greater than 100, D is between 1 and 100%; when R is strictly greater than 50 and less than or equal to 100, D is between 1 and 90%; when R is strictly greater than 10 and less than or equal to 50, D is between 1 and 80%; when R is strictly greater than 5 and less than or equal to 10, D is between 1 and 60%; when R is strictly greater than 1 and less than or equal to 5, D is between 1 and 50%; when R is strictly greater than 0.1 and less than or equal to 1, D is between 1 and 30%; when R is strictly greater than 0.01 and less than or equal to 0.1, D is between 1 and 10%; when R is less than or equal to 0.01, D is between 1 and 5%.

10. The polymer according to claim 9, characterized in that when R is strictly greater than 100, D is between 25 and 95%; when R is strictly greater than 50 and less than or equal to 100, D is between 25 and 85%; when R is strictly greater than 10 and less than or equal to 50, D is between 25 and 75%; when R is strictly greater than 5 and less than or equal to 10, D is between 2 and 50%; when R is strictly greater than 1 and less than or equal to 5, D is between 2 and 40%; when R is strictly greater than 0.1 and less than or equal to 1, D is between 2 and 25%; when R is strictly greater than 0.01 and less than or equal to 0.1, D is between 1 and 8%; when R is less than or equal to 0.01, D is between 1 and 4%.

11. The polymer according to claim 9, characterized in that when R is strictly greater than 100, D is between 50 and 90%; when R is strictly greater than 50 and less than or equal to 100, D is between 50 and 80%; when R is strictly greater than 10 and less than or equal to 50, D is between 50 and 70%; when R is strictly greater than 5 and less than or equal to 10, D is between 5 and 40%; when R is strictly greater than 1 and less than or equal to 5, D is between 4 and 30%; when R is strictly greater than 0.1 and less than or equal to 1, D is between 3 and 20%; when R is strictly greater than 0.01 and less than or equal to 0.1, D is between 1 and 6%; when R is less than or equal to 0.01, D is between 1 and 3%.

12. The polymer according to claim 1, characterized in that quantity A of 2-acrylamido-2-methylpropane sulfonic acid, in acid and/or salified form, additionally contains between 300 and 10,000 ppm by weight 2-methylidene-1,3-propylenedisulfonic acid.

13. Use of the polymer of claim 1 in a field selected from oil and gas recovery, water treatment, sludge treatment, papermaking, construction, mining, cosmetic formulation, detergent formulation, textile manufacturing, and agriculture.

14. Use of the polymer according to claim 1 as a flocculant, viscosity-reducing agent, thickening agent, absorbing agent, friction-reducing agent or plasticizer or superplasticizer.

15. The polymer according to claim 3, characterized in that the polymer is further obtained from a quantity B of 2-acrylamido-2-methylpropane sulfonic acid, in acid and/or salified form, containing strictly less than 200 ppm by weight of 2-methyl-2-propenyl sulfonic acid, in acid and/or salified form.

16. The polymer according to claim 15, characterized in that the polymer is water-soluble and has a weight-average molecular weight greater than 100,000 g/mol and less than or equal to 40 million g/mol.

17. The polymer according to claim 16, characterized in that the polymer is a homopolymer of 2-acrylamido-2-methylpropane sulfonic acid, in acid and/or salified form, or a copolymer of 2-acrylamido-2-methylpropane sulfonic acid, in acid and/or salified form, further comprising at least one monomer chosen from the group comprising nonionic monomers, anionic monomers, cationic monomers, zwitterionic monomers, and mixtures thereof.

18. The polymer according to claim 17, characterized in that the polymer is obtained at least from 2-acrylamido-2-methylpropane sulfonic acid, in acid and/or salified form, the total quantity of which contains strictly less than 20,000 ppm by weight of 2-methyl-2-propenyl sulfonic acid, in acid and/or salified form.

19. The polymer according to claim 18, characterized in that the proportion D of quantity A relative to the total quantity of 2-acrylamido-2-methylpropane sulfonic acid, in acid and/or salified form, is determined from the ratio R defined according to the following equation (1): $\begin{array}{cc}R=\frac{{10}^{14}}{{\left[\mathrm{IBSA}\right]}^2*C^2\mathrm{Mw}}& \left(1\right)\end{array}$ wherein, [IBSA] is the concentration in ppm by weight in quantity A of 2-methyl-2-propenyl-1-sulfonic acid; Mw is the weight-average molecular weight of the polymer expressed in g/mol; C is a coefficient equal to 0.2 when Mw is less than or equal to 1 million, equal to 0.6 when Mw is strictly greater than 1 million and less than or equal to 10 million, and equal to 0.8 when Mw is strictly greater than 10 million; when R is strictly greater than 100, D is between 1 and 100%; when R is strictly greater than 50 and less than or equal to 100, D is between 1 and 90%; when R is strictly greater than 10 and less than or equal to 50, D is between 1 and 80%; when R is strictly greater than 5 and less than or equal to 10, D is between 1 and 60%; when R is strictly greater than 1 and less than or equal to 5, D is between 1 and 50%; when R is strictly greater than 0.1 and less than or equal to 1, D is between 1 and 30%; when R is strictly greater than 0.01 and less than or equal to 0.1, D is between 1 and 10%; when R is less than or equal to 0.01, D is between 1 and 5%.

20. The polymer according to claim 19, characterized in that quantity A of 2-acrylamido-2-methylpropane sulfonic acid, in acid and/or salified form, additionally contains between 300 and 10,000 ppm by weight 2-methylidene-1,3-propylenedisulfonic acid; and when R is strictly greater than 100, D is between 50 and 90%; when R is strictly greater than 50 and less than or equal to 100, D is between 50 and 80%; when R is strictly greater than 10 and less than or equal to 50, D is between 50 and 70%; when R is strictly greater than 5 and less than or equal to 10, D is between 5 and 40%; when R is strictly greater than 1 and less than or equal to 5, D is between 4 and 30%; when R is strictly greater than 0.1 and less than or equal to 1, D is between 3 and 20%; when R is strictly greater than 0.01 and less than or equal to 0.1, D is between 1 and 6%; when R is less than or equal to 0.01, D is between 1 and 3%.

Description

EXAMPLES

Example 1 (comparative): Preparation of a Homopolymer of 2-acrylamido-2-methylpropane sulfonic acid

[0080] To a 2000 mL beaker are added 390.5 g of deionized water, 262 g of 50% lye (by weight in water) and 847.5 g of 2-acrylamido-2-methylpropane sulfonic acid crystals containing 132 ppm IBSA.

[0081] The solution thus obtained is cooled to between 5 and 10° C. and transferred to an adiabatic polymerization reactor, nitrogen bubbling is carried out for 30 minutes in order to eliminate any trace of dissolved oxygen.

[0082] The following are then added to the reactor: [0083] 0.45 g of 2,2′-azobisisobutyronitrile, [0084] 1.5 mL of an aqueous solution at 2.5 g/L of 2,2′-Azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride, [0085] 1.5 mL of an aqueous solution at 1 g/L of sodium hypophosphite, [0086] 1.5 mL of an aqueous solution at 1 g/L of tert-butyl hydroperoxide, [0087] 1.5 mL of an aqueous solution containing 1 g/L of ammonium sulfate and iron(II) hexahydrate (Mohr's salt).

[0088] After a few minutes, the nitrogen inlet is closed, and the reactor is closed. The polymerization reaction takes 4 hours to reach a peak temperature. The resulting rubbery gel is chopped and dried to obtain a coarse powder which is then ground and sieved to obtain the 2-acrylamido-2-methylpropane sulfonic acid homopolymer in powder form.

Example 2 (comparative): Preparation of an acrylamide/2-acrylamido-2-methylpropane sulfonic acid copolymer (75/25 mol %)

[0089] 549.55 g of deionized water, 520.5 g of acrylamide in 50% solution (by weight in water), 97.6 g of 50% sodium hydroxide solution (by weight in water) and 316.2 g of 2-acrylamido-2-methylpropane sulfonic acid crystals containing 132 ppm of IBSA are added a 2000 mL beaker. The same polymerization and gel processing procedures as in Example 1 are carried out. A polymer in powder form is obtained.

Example 3 (comparative): Preparation of an acrylamide/2-acrylamido-2-methylpropane sulfonic acid copolymer (75/25 mol %)

[0090] The same preparation as in Example 2 is carried out, with the only difference being that 0.5 mL of a 1 g/L aqueous solution of sodium hypophosphite is used instead of 1.5 mL. A polymer in powder form is obtained.

Example 4 (Invention)

[0091] The same preparation as in Example 1 is performed with the only difference being that 53% by weight of the 2-acrylamido-2-methylpropane sulfonic acid, or 449.175 g, are substituted with 2-acrylamido-2-methylpropane sulfonic acid containing 1042 ppm IBSA. Proportion D is 53%.

Example 5 (Invention)

[0092] The same preparation as in Example 2 is performed with the only difference being that 55% of the 2-acrylamido-2-methylpropane sulfonic acid, or 173.91 g, are substituted with 2-acrylamido-2-methylpropane sulfonic acid containing 715 ppm IBSA. Proportion D is 55%.

Example 6 (Invention)

[0093] The same preparation as in Example 3 is performed with the only difference being that 23% of the 2-acrylamido-2-methylpropane sulfonic acid, or 72.726 g, are substituted with 2-acrylamido-2-methylpropane sulfonic acid containing 1210 ppm IBSA. Proportion D is 23%.

Example 7 (Invention)

[0094] The same preparation as in Example 1 is performed with the only difference being that 58% by weight of the 2-acrylamido-2-methylpropane sulfonic acid, or 491.55 g, are substituted with 2-acrylamido-2-methylpropane sulfonic acid containing 1042 ppm IBSA. Proportion D is 58%.

Example 8 (Invention)

[0095] The same preparation as in Example 2 is performed with the only difference being that 60% of the 2-acrylamido-2-methylpropane sulfonic acid, or 189.72 g, are substituted with 2-acrylamido-2-methylpropane sulfonic acid containing 715 ppm by weight of 2-methyl-2-propenyl-1-sulfonic acid. Proportion D is 60%.

Example 9 (Invention)

[0096] The same preparation as in Example 3 is performed with the only difference being that 30% of the 2-acrylamido-2-methylpropane sulfonic acid, or 94.86 g, are substituted with 2-acrylamido-2-methylpropane sulfonic acid containing 1210 ppm IBSA. Proportion D is 30%.

[0097] The weight-average molecular weight of the polymers of Examples 1 to 9 is measured according to the method described above, and the results are presented in Table 1.

TABLE-US-00001 TABLE 1 Weight-average molecular weight of polymers 1 to 9, R ratio and D proportion of polymers 4 to 9. Weight-average (IBSA) molecular weight (ppm with (in millions respect to Proportion Example of g/mol) C quantity A) R D 1 1.12 — — — 2 6.78 — — — 3 11.23 — — — 4 1.10 0.60 1042 232.6 53% 5 6.81 0.60 715 79.8 55% 6 11.22 0.80 1210 9.5 23% 7 1.05 0.60 1042 243.7 58% 8 6.72 0.60 715 80.9 60% 9 11.08 0.80 1210 9.6 30%

[0098] Thus, substitution of some of the ATBS of good purity (<200 ppm of IBSA) with ATBS of poor purity (250-20,000 ppm of IBSA) does not significantly impact the molecular weight of the polymers.

Example 10—Application Test 1

[0099] Polymers 2, 3, 5, 6, 8 and 9 are dissolved in tap water in order to obtain aqueous solutions having a concentration of 0.1% by weight of the polymer relative to the total weight of the solution. The solutions are stirred mechanically at 200 rpm until the complete solubilization of the polymers and clear and homogeneous solutions are obtained.

[0100] A series of flocculation tests are carried out on an aqueous effluent containing 30 g/L of Kaolin, 1 g/L of calcium chloride and 100 g/L of crushed ore.

[0101] The tests are carried out in Manual Jar Test according to the following protocol: [0102] tubes are filled with the effluent; [0103] different dosages of a polymeric solution are injected; [0104] 5 reversals of the Jar Test are carried out for incorporating the polymeric aqueous solution in the effluent suspension.

[0105] The results presented in Table 2 summarize the sedimentation rate according to the dosage of polymer used in relation to the quantity of effluent.

TABLE-US-00002 TABLE 2 Results of flocculation tests Polymer Dosage (g/ton) 4 8 12 16 Example Sedimentation Rate (m/h) 2 10 22 41 65 3 12 24 41 63 5 11 23 42 64 6 10 22 43 64 8 10 22 42 62 9 9 21 41 62

[0106] Thus, substitution of one part of the ATBS of good purity (<250 ppm of IBSA) with ATBS of poor purity (250-20,000 ppm of IBSA) does not significantly impact the molecular weight of the polymers.

Example 11: Application Test 2

[0107] Solutions of polymers 1, 4 and 7 are prepared at an active concentration of 1,000 ppm by weight in a brine containing water, 30,000 ppm by weight of NaCl and 3,000 ppm by weight of CaCl.sub.2.Math.2H.sub.2O. The polymers are tested in an enhanced oil recovery application by injection of polymer solutions. The filtration quotient (FR) is measured on filters having a pore size of 1.2 μm representative of low permeability deposits.

[0108] The term filtration quotient (or filter ratio denoted “FR”) is used in this document to designate a test used to determine the performance of the polymer solution under conditions approaching the permeability of the deposit consisting in measuring the time taken by given volumes/concentrations of solution to pass through a filter. The FR generally compares the filterability of the polymer solution for two consecutive equivalent volumes, which indicates the tendency of the solution to clog the filter. Lower FRs indicate better performance.

[0109] The test used to determine the FR consists of measuring the times it takes for given volumes of solution containing 1000 active ppm of polymer to flow through a filter. The solution is contained in a pressurized cell at two bars of pressure and the filter is 47 mm in diameter and of defined pore size. Generally, FR is measured with filters having a pore size of 1.2 μm, 3 μm, 5 μm or 10 μm. In the example, the pore size is 1.2 μm.

[0110] The times required to obtain 100 mL (t.sub.100mL); 200 mL (t.sub.200mL) and 300 mL (t.sub.300mL) of filtrate are therefore measured. The filtration quotient FR is defined by:

[00002]$\mathrm{FR}=\frac{t_{300\mathrm{mL}}-t_{200\mathrm{mL}}}{t_{200\mathrm{mL}}-t_{\mathrm{`100}\mathrm{mL}}}$

[0111] Times are measured to the nearest 0.1 second.

[0112] The FR thus represents the capacity of the polymer solution to clog the filter for two equivalent consecutive volumes.

[0113] The results are shown in Table 3 below.

TABLE-US-00003 TABLE 3 FR Results Example FR 1 1.16 4 1.16 7 1.17

[0114] Thus, substituting part of good purity ATBS (<300 ppm IBSA, or even <250 or <200 ppm IBSA) with ATBS of poor purity (250-20,0000 ppm IBSA or 300-20,0000) does not significantly impact polymer performance.