Synthetic methods for preparing rheology-modifying polymers and their uses

Abstract

To provide terpolymers that can be used as aqueous rheological modifiers.SOLUTION: The invention relates to a UV-initiated RAFT-type polymerization for producing hydrophobically associative terpolymers in an aqueous solution. The terpolymers produced by this method can be used as aqueous rheological modifiers. Specifically, the invention relates to a hydrophobically associating terpolymers and a method to produce the same using a light initiated iniferter. The monomers used in the present invention are selected from: a monomer having a water-soluble monoethylenically unsaturated group; a monomer having an ionic water-soluble monoethylenically unsaturated group; and a monomer having a monoethylenically unsaturated monomer capable of forming hydrophobically associative bonds in aqueous medium. The iniferter is initiated with light of wavelength between 250 to 400 nm. The resultant terpolymer is produced in a cost-effective, simple, and one-step process and can be used to thicken aqueous mediums with less or equal amounts of polymer than currently available.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] Reference to Pending Application This application claims the benefit of previously filed US Provisional Patent Application No. 62 / 699,033. The present disclosure relates to novel UV-initiated RAFT-type polymerizations for producing hydrophobic associative terpolymers in an aqueous, facile synthetic method, and in particular to producing polymers for use as aqueous rheology modifiers. [Background technology]

[0002] The rheology modification of aqueous solutions to obtain a desired viscosity for a particular application has many industrially relevant applications. These rheology modifiers are often polymeric and can be used as additives in cosmetics, cleaning agents in wastewater treatment plants, retention agents in papermaking, and rheology modifiers in enhanced oil recovery, to name a few.

[0003] A common example of this is directed to fluids used in oil and gas well stimulation, designed to open fractures and transport proppant into the fractures. When water is used alone, its relatively low viscosity prevents efficient transport. Rheology modifiers are used to improve overall hydrocarbon capture within the reservoir. To achieve the desired rheological properties, polymers are often used to increase the viscosity of the fluid.

[0004] Various polymers have been used to increase the viscosity of aqueous media, typically polyacrylamide-based systems containing ionic moieties consisting of acrylate- or sulfate-based acrylamides. While these copolymers perform well in water with low total dissolved solids (TDS), their thickening properties are significantly reduced when high TDS wells are encountered, especially in the presence of divalent cationic salts. To counteract this effect, the introduction of hydrophobic groups into these polymers can increase the viscosity of high TDS wells. These polymers associate in solution based on intermolecular hydrophobic interactions, which act as pseudo-crosslinkers in aqueous solutions. Viscosity increases in freshwater and significantly improved in the presence of monovalent and divalent cations in solution have been observed.

[0005] Current technologies for polymers that increase the viscosity of a target solution require additives (i.e., surfactants, amphiphilic non-polymerizable compounds, RED / OX initiation systems) or several synthetic steps (i.e., synthesis of macroinitiators or macrochain transfer agents: macro-CTAs) to successfully achieve the final target physical properties. The present invention provides the synthesis of ultra-high molecular weight polymers (>1.0 × 10) in aqueous media without the need for additives or additional synthetic steps. 6 The goal is to produce 1000 mg / mol of PEG.

[0006] Currently, one of the most common methods to synthesize these hydrophobic associative water-soluble polymers (HAPs), also known as amphiphilic or associative polymers, is through controlled free radical polymerization, more specifically, reversible addition-fragmentation chain transfer / macromolecular design via xanthate exchange (RAFT / MADIX).

[0007] Prior art describing this process includes Taton et al., Macromol. Rapid Commun. 22, 1497-1503, 2001, in which a method was developed using MADIX technology to obtain well-defined copolymers based on acrylic acid and acrylamide monomer units. As an example, a typical experiment involved the use of 1.0 g (4.86 x 10 -3mol) xanthate 1{methyl 2-[(ethoxycarbonothioyl)thio]-propanoate}, 24.2 g (0.336 mol) acrylic acid, 0.250 g (9.66 × 10 -4 73 g of 4,49-azo(4-cyanopentanoic acid) and 73 g of a mixture of deionized water and isopropyl alcohol (4:1 v / v) were introduced into a degassed two-neck flask under nitrogen and heated at 70 °C for 8 h. The use of xanthates in the MADIX method has been described as an alternative route for the direct and facile synthesis of well-defined functional statistical diblock and triblock copolymers containing acrylamide and acrylic acid units. However, this polymerization only provided access to polymers with Mn values ​​of approximately 10,000 g / mol, and required the use of the organic solvent isopropyl alcohol.

[0008] Read et al., Polym. Chem. 5, 2202-2207, 2014, 10 5 ~10 6 p(AM-stat-AMPS) statistical copolymers in the g / mol range were successfully prepared. The polymerizations were carried out using a low molar mass hydrophilic macro-RAFT / MADIX agent (DP), synthesized from a hydrophobic O-ethyl-S-(1-methoxycarbonyl)ethyl dithiocarbonate agent (Rhodixan A1® from Solvay), which was used as a mediator. n The synthesis was carried out in purely aqueous media with an oligo(acrylamide) of approximately 7 (denoted P7-XA1). The synthesis relied on low-temperature redox initiation based on ammonium persulfate / sodium formaldehyde sulfoxylate dihydrate (APS / NaFS, 50 / 50, w / w) as the oxidant / reductant pair.

[0009] Cadix et al., SPE-174210-MS, describes a micellar solution of surfactants prepared by solubilizing a fixed amount of the surfactant sodium dodecyl sulfate (SDS) in water. Next, a hydrophobic monomer (typically containing an acrylamide group, a hydrophobic component, and a polymerizable component consisting of a linkage between the two) was added to the micellar solution, and the mixture was stirred at ambient temperature or in a warm water bath (35 °C). Next, a solution of hydrophilic monomers (AM and AMPS) was prepared in water with the required monomer composition and a solids content typically ranging from 10 to 35 wt%. To this solution, the micellar solution of hydrophobic monomers was added, the amount added calculated to achieve the required theoretical composition of hydrophobic monomers in the final polymer (M n theoretical =2.0×10 6 g / mol). The reaction mixture was stirred at ambient temperature until a homogeneous solution was obtained, after which Rhodixan A1 O-ethyl-S-(1-methoxycarbonylethyl) xanthate (MADIX transfer agent) was added in an amount calculated from the target theoretical molecular weight. The reaction mixture was then initiated using an aqueous-based RED / OX type initiation system and polymerized overnight under "quasi-adiabatic" conditions.

[0010] U.S. Patent Application Publication No. 2012 / 0129739A1 described a water-soluble HAP containing a monoethylenically unsaturated, water-soluble, surface-active monomer (a) and a monoethylenically unsaturated, hydrophilic monomer (b) different from monomer (a). The copolymer was prepared in the presence of a non-polymerizable surfactant and has significant thickening properties in aqueous systems. However, the system requires a non-polymerizable additive to achieve significant thickening behavior.

[0011] Carmean et al., Chem 2, 93-101, 2017, describe a method for producing ultra-high molecular weight (UHMW) polymers using mild UV irradiation of thiocarbonylthio and xanthate compounds in the presence of acrylamide monomers. They use aqueous conditions, resulting in well-defined UHMW polymers for controlled radical polymerization (i.e., RAFT polymerization). This light-mediated RAFT polymerization approach has been shown to produce polymers with a degree of polymerization exceeding 85,000, yielding 8x106 The number-average molecular weights exceeding 1000 g / mol are reached. This disclosure specifically addresses the synthesis of poly(dimethylacrylamide) (PDMA). The light-mediated polymerization described uses a RAFT agent to produce polymers in the UHMW range, even at low temperatures and relatively fast reaction times. However, this methodology does not describe the synthesis of polymers other than poly(dimethylacrylamide).

[0012] RAFT / MADIX polymerization methods have been used to create a variety of hydrophobic associative copolymers and terpolymers to improve the rheological performance of fluids in hydrocarbon capture. However, these polymerizations require the use of RED / OX-mediated initiation, high temperatures (e.g., 70 °C), and the use of macro-CTAs or surfactants to create micelles necessary for polymer molecular weight control. These methods require more steps and greater costs for polymer preparation.

[0013] Despite all the prior art in the field of HAP and RAFT polymerization, certain challenges remain with regard to increasing the molecular weight of HAP without the need for complex micellar systems, RED / OX initiators, or macro-CTAs. In particular, the present invention proposes polymers and methodologies that offer a novel combination of elements for producing terpolymers in a one-pot aqueous reaction that achieves excellent thickening properties through hydrophobic associative interactions, processability, ease of synthesis, and a single iniferter that performs the initiation / propagation of the terpolymer system.

[0014] The contents of all referenced documents are incorporated herein by reference in their entirety for all purposes. Summary of the Invention

[0015] It is an object of the present invention to provide a synthetic method for making terpolymers for rheology modification of aqueous solutions.

[0016] According to one embodiment of the present invention, a water-soluble monoethylenically unsaturated group-containing monomer A, an ionic water-soluble monoethylenically unsaturated group-containing monomer B, C and a monomer having a monoethylenically unsaturated monomer capable of forming hydrophobic associative bonds in an aqueous medium and suitable for aqueous polymerization conditions. B Terpolymers are provided which result from the polymerization of a mixture of monomers selected from:

[0017] According to a further aspect of the present invention, there is provided a process for preparing a terpolymer, comprising the steps of: i. The following groups: a water-soluble monomer A having a monoethylenically unsaturated group; Ionic water-soluble monoethylenically unsaturated monomers C , and Monomers capable of forming hydrophobic associative bonds in aqueous media and having monoethylenically unsaturated monomers suitable for aqueous polymerization conditions B a mixture of monomers selected from R 1’ -(C=S)-SZ 1 or R 2’ -S-(C=S)-SZ 2 (In the formula, R 1’ is methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, t-butoxy, benzyl, phenyl, N-methylaniline, Z 1 is propanoic acid, propanoate, phenylpropan-2-yl, cyanomethyl, cyanopropan-2-yl, R 2’ is a straight or branched alkyl chain (C1 to C12 carbon length), benzyl, phenyl, isobutyronitrile, propanoate, propanoic acid, benzyl isobutyrate, 2-(pyridin-2-yldisulfanyl)ethyl propionate; Z 2propanoate, propanoic acid, methyl, ethyl, propyl, butyl, pentyl, hexyl, phenyl, benzyl, benzyl isobutyrate, PEGylated 2-cyanopropanoic acid to form a reaction mixture; ii. sparging the reaction mixture with an inert gas; and iii. Initiating the iniferter with light of wavelengths between 250 and 400 nm A process is provided, including:

[0018] According to an additional aspect of the present invention, there is provided a method of thickening an aqueous solution by adding to the aqueous solution a terpolymer according to an aspect of the present invention in an amount sufficient to thicken the aqueous solution.

[0019] According to a further embodiment of the present invention, there is provided a method of using the aqueous solution of the present invention to transport a proppant, typically sand, treated sand, or engineered ceramic material, such that the proppant functions to hold open induced hydraulic fractures.

[0020] According to a further aspect of the present invention, there is provided use of a terpolymer according to an aspect of the present invention for enhancing oil recovery by injecting an aqueous solution comprising the terpolymer at a concentration of 0.01 to 5 wt % into a mineral oil deposit through at least one injection well, and for removing crude oil from the deposit through at least one production well.

[0021] According to a further embodiment of the invention, monomer A is present in an amount of 25.0 to 99.9 mol %, each based on the total molar amount of all components in the copolymer, and monomer C is present in an amount of 25.0 to 99.9 mol %, and the monomer B is present in an amount of 0.1 to 5.0 mole percent.

[0022] According to a further embodiment of the present invention, there is provided a process for the preparation of terpolymers, wherein the preparation is carried out in a solvent system consisting of water and a polar protic or polar aprotic solvent in a ratio ranging from 100 / 0 to 51 / 49 from water to the polar protic or polar aprotic solvent.

[0023] According to yet another embodiment of the present invention there is provided the use of a terpolymer according to an aspect of the present invention for adjusting the viscosity of a cosmetic preparation or a pharmaceutical excipient or a pharmaceutical formulation.

[0024] According to a further embodiment of the present invention there is provided the use of a terpolymer according to an aspect of the present invention in the treatment of water, wastewater to remove unwanted impurities from the solution.

[0025] According to a further embodiment of the present invention there is provided the use of a terpolymer according to an aspect of the present invention as a retention aid and strengthening agent in papermaking.

[0026] The foregoing additional aspects and embodiments of the present disclosure will become apparent to those skilled in the art in view of the detailed description of various embodiments and / or aspects, a brief description of which is provided below, taken with reference to the drawings.

[0027] These and other advantages of the present disclosure will become apparent upon reading the following detailed description and upon reference to the drawings. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is an example of a synthetic method for producing hydrophobic associative terpolymers.

[0029] [Figure 2] 1H-NMR of polymerization in deuterated water showing the kinetics of the reaction.

[0030] [Figure 3] Pseudo first order kinetic plot showing nearly linear behavior up to 120 min (98% conversion).

[0031] [Figure 4] 1 is a GPC trace of RI response displaying the molecular weight of polymers with different target weight average molecular weights for Examples 5, 6, and 7.

[0032] [Figure 5] (A) Frequency sweep tests, (B) flow curves, and (C) strain sweep tests of all aqueous terpolymer solutions. Squares and circles represent 25°C and 70°C, respectively. The polymers analyzed include Example 9, Example 2, Example 8, and Example 4. All rheological tests were performed three or four times for each solution, and the average of each result is presented in this study. For values ​​on a log-log scale, the error is within the data point markers and cannot be observed. DETAILED DESCRIPTION OF THE INVENTION

[0033] While the present disclosure is susceptible to various modifications and alternative forms, specific embodiments or implementations have been shown by way of example in the drawings and are described in detail herein. It should be understood, however, that the present disclosure is not intended to be limited to the particular forms disclosed. Rather, the present disclosure is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

[0034] An object of embodiments of the present invention is to provide hydrophobic associative terpolymers in a cost-effective, simple, one-step process that can thicken aqueous media with less or equal amounts of polymer than currently available.

[0035] The objective is to use water-soluble UV-initiated iniferters in a one-pot synthesis at ambient temperature to obtain the following, typically within 2 hours: a water-soluble monomer A having a monoethylenically unsaturated group; Ionic water-soluble monomer having a monoethylenically unsaturated group, different from monomer A C , and Monomers capable of forming hydrophobic associative bonds in aqueous media and having monoethylenically unsaturated monomers that are soluble under aqueous polymerization conditions B , This is achieved by providing a UHMW polymer consisting of: Monomer A is R 1 -(C=C)-(C=O)-OR 2 or R 1 -(C=C)-(C=O)-N-(R 3 )-R 4 and Monomer B is R 1 -(C=C)-(C=O)-OR 5 or R 1 -(C=C)-(C=O)-N-(R 6 )-R 7 or R 1 -(C=C)-(C=O)-R 8 and Monomer C is R 1 -(C=C)-(C=O)-OR 9 or R 3 -(C=C)-(C=O)-N-(R 10 )-R 11 or R 1 (C=C)-R 12 and R 1 is H or methyl, R 2 are methyl, ethyl, propyl, butyl, epoxymethyl, methanol, ethanol, N,N-dimethylethyl, PEG (molecular weight: 50 to 1000 g / mol), benzyl, and phenyl. R 3 is H, methyl, or ethyl, R 4 is H, methyl, ethyl, isopropyl, propan-2-ol, R 5 is H, methyl, ethyl, propyl, butyl, pentyl, hexyl, C9 to C24 linear or branched chain, R 6 is poly(ethylene glycol) n(n is 2 to 20 units), PEGylated hydrocarbon, N-methoxyisobutyl, wherein the hydrocarbon is an aromatic group having a linear or branched alkyl chain of 4 to 20 carbons in length; R 7 teeth, H、 Poly(ethylene glycol) n (n is 2 to 20 units), PEGylated hydrocarbon, N-methoxyisobutyl, wherein the hydrocarbon is an aromatic group having a linear or branched alkyl chain of 4 to 20 carbons in length; R 8 is poly(ethylene glycol) n (n is 2 to 20 units), PEGylated hydrocarbon, N-methoxyisobutyl, wherein the hydrocarbon is an aromatic group having a linear or branched alkyl chain of 4 to 20 carbons in length; R 9 O - , OH, NH3 + , 2-amino-2-methylpropane-1-sulfonic acid in sodium salt or neutral form, poly(ethylene glycol) n (n is 2 to 20 units), PEGylated hydrocarbon, N-methoxyisobutyl, wherein the hydrocarbon is an aromatic group having a linear or branched alkyl chain of 4 to 20 carbons in length; R 10 H, O - , OH, NH3 + , sodium salt or neutral form of 2-amino-2-methylpropane-1-sulfonic acid , sodium salt of 2-methylpropane-1-sulfonic acid and R 11 teeth, Doesn't exist or O - , OH, NH3 + , 2-amino-2-methylpropane-1-sulfonic acid in sodium salt or neutral form, R 12 is poly(ethylene glycol) n (n is 2 to 20 units), PEGylated hydrocarbon, N-methoxyisobutyl, where the hydrocarbon is an aromatic group having a linear or branched alkyl chain of 4 to 20 carbons in length.

[0036] Iniferters are: R 1’-(C=S)-SZ 1 :In the formula, R 1’ is methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, iso-butoxy, t-butoxy, benzyl, phenyl, N-methylaniline, Z 1 is propanoic acid, propanoate, phenylpropan-2-yl, cyanomethyl, cyanopropan-2-yl, and R 2’ -S-(C=S)-SZ 2 :In the formula, R 2’ is a straight or branched alkyl chain (C1 to C12 carbon length), benzyl, phenyl, isobutyronitrile, propanoate, propanoic acid, benzyl isobutyrate, 2-(pyridin-2-yldisulfanyl)ethyl propionate; Z 2 are propanoates, propanoates, methyl, ethyl, propyl, butyl, pentyl, hexyl, phenyl, benzyl, benzyl isobutyrate, PEGylated 2-cyanopropanoic acid (PEG 50-1000g / mol), is selected from the group consisting of:

[0037] The iniferter is initiated with light of wavelength between 250 and 400 nm, preferably 365 nm.

[0038] The polymerization concentration is 0.5 to 4.0M.

[0039] The general experimental procedure is as follows.

[0040] The reaction involves 10-98% molar ratio of monomer A, 5-90% molar ratio of monomer B, C and monomers with a molar ratio of 0.05 to 10% BThe reaction mixture includes a UV-initiated iniferter combination and a water-soluble UV-initiated iniferter. The reaction mixture is sparged with an inert gas (i.e., nitrogen, argon, helium) for approximately 5-60 minutes prior to initiation. The initiation light source is 250-400 nm, the temperature is 5-95°C, and the solvent mixture is preferably a water to organic solvent ratio of 100:0 to 1:99, with the secondary solvent being highly to somewhat miscible with water and either polar protic or polar aprotic. Depending on the type and ratio of monomers, the reaction typically takes 1-12 hours.

[0041] The following should be considered as non-limiting examples of terpolymer synthesis according to embodiments of the present invention.

[0042] See FIG. 1 for an example of a synthetic method for preparing hydrophobic associative terpolymers.

[0043] Example 1:

[0044] Monomer A is 74.5 mmol, C is 25.0 mmol, monomer B 0.5 mmol of acrylamide (5.30 g), more specifically, acrylamide (2.42 g), sodium acrylate (2.42 g), and N-(isobutoxymethyl)acrylamide (0.08 g) were used for the synthesis of the terpolymer. The monomers were dissolved in 50 mL of HO in a 100 mL Schlenk flask. An initiator stock solution (416 μL of 1 mg / mL in DMSO) was added to the monomer solution. The reaction mixture was sparged with N for 30 minutes, then irradiated with 365 nm light to initiate the reaction and stirred for 6 hours. After 15 minutes, the mixture became a clear, viscous gel.

[0045] Example 2:

[0046] Monomer A is 74.0 mmol, C is 25.0 mmol, monomer B is 1.0 mmol, and monomer A is acrylamide (5.26 g), monomer CSodium acrylate (2.42 g) and N-(isobutoxymethyl)acrylamide (0.016 g) were used to synthesize the terpolymer. The monomers were dissolved in 50 mL of HO in a 100 mL Schlenk flask. An initiator stock solution (416 μL of 1 mg / mL in DMSO) was added to the monomer solution. The reaction mixture was sparged with N for 30 minutes, then irradiated with 365 nm light to initiate the reaction and stirred for 6 hours. After 30 minutes, the mixture became a clear, viscous gel.

[0047] Example 3:

[0048] Monomer A is 73.0 mmol, C is 25.0 mmol, monomer B 2.0 mmol of acrylamide (5.19 g), more specifically, sodium acrylate (2.42 g), and N-(isobutoxymethyl)acrylamide (0.324 g) were used for the synthesis of the terpolymer. The monomers were dissolved in 50 mL of HO in a 100 mL Schlenk flask. An initiator stock solution (416 μL of 1 mg / mL in DMSO) was added to the monomer solution. The reaction mixture was sparged with N for 30 minutes, then irradiated with 365 nm light to initiate the reaction and stirred for 6 hours. After 15 minutes, the mixture became a clear, viscous gel.

[0049] Example 4:

[0050] Monomer A is 71.0 mmol, C is 25.0 mmol, monomer B 4.0 mmol of acrylamide (5.05 g), more specifically, sodium acrylate (2.42 g), and N-(isobutoxymethyl)acrylamide (0.065 g) were used for the synthesis of the terpolymer. The monomers were dissolved in 50 mL of HO in a 100 mL Schlenk flask. An initiator stock solution (416 μL of 1 mg / mL in DMSO) was added to the monomer solution. The reaction mixture was sparged with N for 30 minutes, then irradiated with 365 nm light to initiate the reaction and stirred for 6 hours. After 30 minutes, the mixture became a clear, viscous gel.

[0051] Figure 2 shows the kinetics of the reaction according to Example 4. 1 See H-NMR. The reaction progresses from bottom to top at time intervals of 0, 30, 60, 120, and 180 minutes.

[0052] Example 5:

[0053] Monomer A is 37.25 mmol, C is 12.5 mmol, monomer B 0.25 mmol of acrylamide (2.65 g), 2-acrylamido-2-methylpropanesulfonic acid sodium salt (4.75 mL of a 50% aqueous solution), and N-(isobutoxymethyl)acrylamide (0.041 g) were used for the synthesis of the terpolymer. The monomers were dissolved in 50 mL of HO in a 100 mL Schlenk flask. An initiator stock solution (416 μL of 1 mg / mL in DMSO) was added to the monomer solution. The reaction mixture was sparged with N for 30 minutes, then irradiated with 365 nm light to initiate the reaction and stirred for 6 hours. After 30 minutes, the mixture became a clear, viscous gel.

[0054] Example 6:

[0055] Monomer A is 74.5 mmol, C is 25.0 mmol, monomer B 0.5 mmol of acrylamide (2.65 g), 2-acrylamido-2-methylpropanesulfonic acid sodium salt (4.78 mL of a 50% aqueous solution), and N-(isobutoxymethyl)acrylamide (0.405 g), respectively, were used for the synthesis of the terpolymer. The monomers were dissolved in 50 mL of HO in a 100 mL Schlenk flask. An initiator stock solution (416 μL of 1 mg / mL in DMSO) was added to the monomer solution. The reaction mixture was sparged with N for 30 minutes, then irradiated with 365 nm light to initiate the reaction and stirred for 6 hours. After 30 minutes, the mixture became a clear, viscous gel.

[0056] Example 7:

[0057] Monomer A is 74.9 mmol, C is 5.0 mmol, monomer B 0.1 mmol of acrylamide (10.60 g), 2-acrylamido-2-methylpropanesulfonic acid sodium salt (19 mL of a 50% aqueous solution), and N-(isobutoxymethyl)acrylamide (0.162 g), respectively, were used in the synthesis of the terpolymer. The monomers were dissolved in 50 mL of HO in a 100 mL Schlenk flask. An initiator stock solution (416 μL of 1 mg / mL in DMSO) was added to the monomer solution. The reaction mixture was sparged with N for 30 minutes, then irradiated with 365 nm light to initiate the reaction and stirred for 6 hours. After 30 minutes, the mixture became a clear, viscous gel.

[0058] Example 8:

[0059] Monomer A is 73.0 mmol, C is 25.0 mmol, monomer B 2.0 mmol of acrylamide (5.19 g), more specifically, acrylamide (1.80 g), acrylic acid (1.80 g), and N-(isobutoxymethyl)acrylamide (0.324 g) were used for the synthesis of the terpolymer. The monomers were dissolved in 50 mL of HO in a 100 mL Schlenk flask. An initiator stock solution (416 μL of 1 mg / mL in DMSO) was added to the monomer solution. The reaction mixture was sparged with N for 30 minutes, then irradiated with 365 nm light to initiate the reaction and stirred for 6 hours. After 15 minutes, the mixture became a clear, viscous gel.

[0060] Example 9:

[0061] Monomer A is 74.5 mmol, C is 25.0 mmol, monomer B0.5 mmol of acrylamide (5.30 g), more specifically, acrylamide (5.18 g), 2-acrylamido-2-methylpropanesulfonic acid (5.18 g), and N-(isobutoxymethyl)acrylamide (0.081 g), respectively, were used in the synthesis of the terpolymer. The monomers were dissolved in 50 mL of HO in a 100 mL Schlenk flask. An initiator stock solution (416 μL of 1 mg / mL in DMSO) was added to the monomer solution. The reaction mixture was sparged with N for 30 minutes, then irradiated with 365 nm light to initiate the reaction and stirred for 3 hours. After 30 minutes, the mixture became a clear, viscous gel.

[0062] Example 10:

[0063] Monomer A is 74.9 mmol, C is 25.0 mmol, monomer B 0.1 mmol, more specifically acrylamide (5.33 g), 2-acrylamido-2-methylpropanesulfonic acid (5.18 g), and poly(oxyethylene) 12 Nonylphenyl ether acrylate (0.109 g) was used for each terpolymer synthesis. The monomer was dissolved in 50 mL of HO in a 100 mL Schlenk flask. Initiator stock solution (416 μL of 1 mg / mL in DMSO) was added to the monomer solution. The reaction mixture was sparged with N for 30 minutes, then irradiated with 365 nm light to initiate the reaction and stirred for 3 hours. After 30 minutes, the mixture became a clear, viscous gel.

[0064] Surprisingly, embodiments of the present invention were able to address all of the desired properties of hydrophobic associative terpolymers.

[0065] [Table 1]

[0066] in deuterated water 1 By monitoring the reaction rate with H-NMR, the reactivity profile could be determined (Figure 2 and Table 1 ).

[0067] The present invention demonstrates 98% conversion of monomer to polymer within 2 hours of reaction time. The total consumption of monomer based on moles in the reaction medium when plotted in pseudo-first order kinetics style shows approximately linear behavior ( Figure 3 )

[0068] Figure 3 shows a pseudo-first-order kinetic plot showing nearly linear behavior up to 120 min, with the reaction approaching completion at 180 min (93%) and reaching full conversion at 300 min. The deviation from linearity is most likely due to the lack of diffusion-limited reaction after the viscous gel is formed.

[0069] After 120 minutes, the reaction deviated from linearity, likely due to the loss of diffusion control within the reaction medium due to the viscosity of the polymer being synthesized. These results suggest that the RAFT reaction behaves as a controlled radical polymerization, allowing for control of the polymer molecular weight and its tailoring to meet the viscosity requirements of a specific application.

[0070] To characterize the molecular weight of these polymers, triple-detection gel permeation chromatography (TD-GPC) was used. A Tosoh ambient GPC model 8220 equipped with a refractive index (RI) detector and dual flow technology was used. Absolute molecular weights were measured using a Viscotek TDA302 with a viscometer, low-angle light scattering detector (LALS), and right-angle light scattering detector (RALS). The GPC was equipped with a TSKgel αM sample column and a TSKgel superH-RC reference column. The sample flow rate was set at 0.750 mL / min, the reference flow rate at 0.325 mL / min, and the temperature of all detectors was set at 30 °C. Terpolymer samples were prepared in 2% KCl, dissolved on a rocker for 24 hours, and filtered through a nylon 0.45 μm syringe filter. The TD-GPC was calibrated using a 20 kDa poly(ethylene oxide) narrow standard and a 72 kDa dextran broad standard.

[0071] Viscosity measurements were obtained by diluting the terpolymer samples with freshwater to a concentration of 3.5 g / L. The dissolution process was facilitated by mixing the solutions in a stand mixer for 1-5 minutes and allowing them to settle to remove air bubbles. The viscosity of the solutions was measured by rotational viscosimetry using a Brookfield viscometer equipped with a spindle appropriate for the relative viscosity of the polymer solution. Salt solutions of the polymer were prepared by adding 2% KCl or 2% seawater (w / w) to the dissolved freshwater solution.

[0072] For Example 1, the polymer was dissolved in 2% KCl aqueous solution at a concentration of 0.1 mg / mL and had the following absolute molecular weight parameters: Mw=2.20×10 6 g / mol, and D = 1.255, and injected into the TD-GPC system. Based on the GPC viscometric data, the intrinsic viscosity (IV) was determined to be 8.52 dl / g.

[0073] Prepared for TD-GPC analysis at a concentration of 0.1 mg / mL, the following absolute molecular weight parameters were obtained: M w =4.62×10 6 g / mol, and D = 1.059, giving a ratio of Monomer A to Monomer B. C versus monomer B A terpolymer having a molar ratio of 73.0:25.0:2.0 (Example 8). The IV of this terpolymer was measured to be 12.4 dl / g.

[0074] [Table 2]

[0075] As shown, an embodiment of the method of the present invention comprises a monomer A, a monomer B, a monomer C, a monomer D, a monomer E, a monomer F, a monomer G, a monomer H, a monomer H, a monomer I ... C ,monomer B Using specific combinations of reagents, including , and UV-active iniferters, and the conditions and concentrations described above, molecular weight can be controlled to be consistent with controlled radical polymerization.

[0076] The polymers of Examples 2, 9, 4, and 8 were analyzed for storage modulus (G'), loss modulus (G''), and flow curves. Samples were prepared by stirring the dry powder form of the polymer in water at a concentration of 4000 ppm for 48 hours. Rheological measurements were performed using an Anton Paar MCR302 rotational rheometer with a concentric cylinder geometry and Rheoplus / 32V3.62 software. Rotational rheometry allows samples to be subjected to either dynamic (sinusoidal) or steady shear deformation, and then the torque response to the applied deformation is measured. The radii of the measuring bob and measuring cup were 13.329 mm outer diameter and 14.463 mm inner diameter, respectively. All rheological measurements were performed at a fixed temperature (T = 25 °C). The temperature of the hot solution was T = 70 °C. Frequency sweep tests were performed within the linear viscoelastic region (LVR). For frequency sweep tests in the angular frequency range of 0.1 rad / s to 10 rad / s, the strain amplitude was set to 0.1%. The strain amplitude for the oscillatory experiments was selected so that the sample always remained in the LVR. Meanwhile, strain amplitude tests were conducted in both the LVR and nonlinear viscoelastic regions (non-LVR). The strain amplitude sweep tests were aimed at investigating the nonlinear viscoelasticity under large amplitude oscillatory shear (LAOS) flow. To avoid the effects of flow instability, torque overload, and wall slip, the angular frequency was set to 0.5 rad / s, and the strain amplitude was varied from 1% to 1000%. The local elastic and viscous responses of the material at small and large instantaneous strains and strain rates were collected after 5–7 cycles for each strain amplitude value to ensure that a steady-state viscoelastic response was achieved. The average of these measurements was reported by the rheometer software.

[0077] The data in Figure 5 for Examples 2, 9, 4, and 8 show that at high frequencies, G'>G" and at low frequencies, G">G', indicating viscoelastic behavior at 4000 ppm. To investigate the effect of temperature change on the polymers presented in Examples 2, 9, 4, and 8, frequency sweep, strain sweep, and flow curve tests were performed at two different temperatures (25°C and 70°C). The change in viscosity between 25°C and 70°C shows a decrease of approximately 10% in all examples. These tests indicate that these polymers exhibit viscoelastic behavior, making them ideal for potential use as propagation agents.

[0078] To demonstrate molecular weight control, monomer A, monomer B, and C , and monomers B Three experiments were conducted by varying the amount of iniferter (Examples 5, 6, and 7) maintained in the reaction mixture while varying the concentration of 1.0, 2.0, and 4.0 total moles present, respectively. These experiments yielded 2.09, 3.65, and 4.40 x 10 initiation times for Examples 5, 6, and 7, respectively. 6 Terpolymers with different experimental molecular weights in g / mol were obtained. These experiments demonstrate that this synthetic methodology confers the ability to tailor the molecular weight and therefore the rheological properties based on desired functionality (Figure 4).

[0079] FIG. 4 shows GPC traces of RI response indicating the molecular weight of polymers with different target weight average molecular weights for Examples 5 (black), 6 (dark grey), and 7 (light grey).

[0080] Solution viscosity data for the terpolymer was obtained using a Brookfield rotational viscometer by preparing a solution in deionized water at a concentration of 3.5 g / L. Monomer A vs. Monomer B C versus monomer B The terpolymer from Example 1 with a molar ratio of 74.5:25.0:0.5 was -1gave values ​​of 1100 cP. Introducing salt into aqueous mixtures containing 2% KCl (w / w) and 2% seawater (w / w) introduced viscosities of 32 and 24 cP, respectively.

[0081] [Table 3]

[0082] Although prior art in the field of rheology-modified polymers can produce polymers with similar compositions, the prior art does not address all of the solutions encompassed by many embodiments of the present invention.

[0083] Taton et al. described the synthesis of diblock and triblock copolymers using RAFT / MADIX technology. However, the inventors were only able to produce polymers with molecular weights of approximately 10,000 g / mol. Embodiments of the present invention allow for the synthesis of diblock and triblock copolymers with faster reaction times and fewer reagents, from 1 to 10×10 6 Polymers can be produced with molecular weights in the g / mol range.

[0084] As described in the prior art by Carmean et al., they demonstrated the ability to synthesize polymers with UV-initiated RAFT agents to produce UHMW polymers. However, while they demonstrated the ability to vary the type of monomer used, they did not demonstrate the synthesis of copolymers or terpolymers. One of the major challenges in the aqueous synthesis of polymers designed to thicken aqueous solutions is the ability to process and characterize these macromolecules. This invention details the synthesis of this challenging technique, but also allows for the complete characterization of the molecular weight properties of these terpolymers.

[0085] Previous inventions, including Read et al. and Cadix et al., have produced terpolymers using UHMW, but these polymers required the use of reagents to create micelles so that the inventors could incorporate hydrophobic groups (as an embodiment of the present invention, the monomer B(See, e.g.,

[10] .) These procedures also require low temperatures and multi-component RED / OX initiator systems. These additional reagents and steps to produce micelles increase the cost and reduce the efficiency of these reactions.

[0086] Various embodiments of the present invention offer advantages over previous inventions due to a novel methodology for producing terpolymers. Through specific combinations of reagents and conditions, the present invention allows for the ability to produce terpolymers with different target molecular weights, narrow PDIs, and simple, relatively fast synthesis in aqueous media. Furthermore, iniferter systems also allow for the incorporation of various monomers in various molar ratios to create terpolymers with desired rheological properties in a one-pot synthesis strategy.

[0087] While particular implementations and applications of the present disclosure have been illustrated and described, it should be understood that the disclosure is not limited to the exact construction and compositions disclosed herein, and that various modifications, changes, and variations may become apparent from the foregoing description without departing from the spirit and scope of the invention as defined in the appended claims. Various aspects or embodiments that can be included in the present invention are summarized as follows. [1]. below: i. a water-soluble monoethylenically unsaturated monomer A; ii. an ionic water-soluble monoethylenically unsaturated monomer B, and iii. Monomer C having a monoethylenically unsaturated monomer capable of forming hydrophobic associative bonds in an aqueous medium and suitable for aqueous polymerization conditions. Terpolymers resulting from the polymerization of a mixture of monomers selected from: [2]. Item 1, wherein the terpolymer has a viscosity of more than 1000 cP in fresh water. [3]. Weight average molecular weight ≧1.0×10 6 g / mol. [4]. Monomer A is R 1 -(C=C)-(C=O)-OR 2 or R 1 -(C=C)-(C=O)-N-(R 3 )-R 4 wherein: R 1 is H or methyl, R 2 are methyl, ethyl, propyl, butyl, epoxymethyl, methanol, ethanol, N,N-dimethylethyl, PEG (molecular weight: 50 to 1000 g / mol), benzyl, and phenyl. R 3 is H, methyl, or ethyl, R 4 is H, methyl, ethyl, isopropyl, propan-2-ol, The terpolymer according to item 1 above. [5]. Monomer B is selected from the following monomers and mixtures thereof: 1 -(C=C)-(C=O)-OR 5 or R 1 -(C=C)-(C=O)-N-(R 6 )-R 7 or R 1 -(C=C)-(C=O)-R 8 wherein: R 1 is H or methyl, R 5 is H, methyl, ethyl, propyl, butyl, pentyl, hexyl, C9 to C24 linear or branched chain, R 6 is poly(ethylene glycol) n (n is 2 to 20 units), PEGylated hydrocarbon, N-methoxyisobutyl, wherein the hydrocarbon is an aromatic group having a linear or branched alkyl chain of 4 to 20 carbons in length; R 7 is poly(ethylene glycol) n (n is 2 to 20 units), PEGylated hydrocarbon, N-methoxyisobutyl, wherein the hydrocarbon is an aromatic group having a linear or branched alkyl chain of 4 to 20 carbons in length; R 8 is poly(ethylene glycol) n (n is 2 to 20 units), PEGylated hydrocarbon, N-methoxyisobutyl, R 2 O - , OH, NH 3 + , sodium salt, or neutral form of 2-amino-2-methylpropane-1-sulfonic acid, The terpolymer according to item 1 above. [6]. Monomer C is selected from the following monomers and mixtures thereof:1 -(C=C)-(C=O)-OR 9 or R 3 -(C=C)-(C=O)-N-(R 10 )-R 11 or R 1 (C=C)-R 12 wherein: R 1 is H or methyl, R 9 O - , OH, NH 3 + , 2-amino-2-methylpropane-1-sulfonic acid in sodium salt or neutral form, poly(ethylene glycol) n (n is 2 to 20 units), PEGylated hydrocarbon, N-methoxyisobutyl, wherein the hydrocarbon is an aromatic group having a linear or branched alkyl chain of 4 to 20 carbons in length; R 10 H, O - , OH, NH 3 + , sodium salt, or neutral form of 2-amino-2-methylpropane-1-sulfonic acid; R 11 O - , OH, NH 3 + , sodium salt, or neutral form of 2-amino-2-methylpropane-1-sulfonic acid; R 12 is poly(ethylene glycol) n (n is 2 to 20 units), PEGylated hydrocarbon, N-methoxyisobutyl, wherein the hydrocarbon is an aromatic group having a linear or branched alkyl chain of 4 to 20 carbons in length; The terpolymer according to item 1 above. [7]. 2. The terpolymer according to item 1, wherein the monomer A is present in an amount of 25.0 to 99.9 mol %, the monomer B is present in an amount of 25.0 to 99.9 mol %, and the monomer C is present in an amount of 0.1 to 5.0 mol %, each based on the total molar amount of all components in the copolymer. [8]. 1. A process for preparing a terpolymer comprising the steps of: i. The following groups: a water-soluble monomer A having a monoethylenically unsaturated group; an ionic, water-soluble, monoethylenically unsaturated monomer B, and Monomer C having a monoethylenically unsaturated monomer capable of forming hydrophobic associative bonds in an aqueous medium and suitable for aqueous polymerization conditions a mixture of monomers selected from R 1 -(C=S)-SZ 1 or R2 -S-(C=S)-SZ 2 (In the formula, R 1 is methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, t-butoxy, benzyl, phenyl, N-methylaniline, Z 1 is propanoic acid, propanoate, phenylpropan-2-yl, cyanomethyl, cyanopropan-2-yl, R 2 is a straight or branched alkyl chain (C1 to C12 carbon length), benzyl, phenyl, isobutyronitrile, propanoate, propanoic acid, benzyl isobutyrate, 2-(pyridin-2-yldisulfanyl)ethyl propionate; Z 2 propanoate, propanoic acid, methyl, ethyl, propyl, butyl, pentyl, hexyl, phenyl, benzyl, benzyl isobutyrate, PEGylated 2-cyanopropanoic acid to form a reaction mixture; ii. sparging the reaction mixture with an inert gas; and iii. initiating the iniferter with light of wavelength between 250 and 400 nm. The process includes: [9]. 9. The process according to item 8, wherein the iniferter is initiated with light of a wavelength of 250 to 400 nm.

[10] . The process according to item 8, wherein the preparation is carried out in a solvent system consisting of water and a polar protic or polar aprotic solvent, wherein the ratio of water to the polar protic or polar aprotic solvent is in the range of 100 / 0 to 51 / 49.

[11] . 9. The process according to claim 8, wherein the terpolymer is produced in the form of a gel.

[12] . 10. A method comprising thickening an aqueous solution by adding a sufficient amount of the terpolymer described in item 1 above to the aqueous solution to thicken the aqueous solution.

[13] . 13. The method according to item 12 above, wherein the solution is used to develop or fully utilize underground mineral oil deposits or natural gas deposits.

[14] . 13. The method according to item 12 above, wherein the solution is used to transport a proppant, typically sand, treated sand, or engineered ceramic material.

[15] . 15. The method of claim 14, wherein the proppant functions to hold open induced hydraulic fractures.

[16] . 13. The method according to item 12, for enhancing oil recovery by injecting the aqueous solution at a concentration of 0.01 to 5 wt% into a mineral oil deposit through at least one injection well, and removing crude oil from the deposit through at least one production well.

[17] . 13. The method according to item 12 above, for increasing the viscosity of a mixture for use in the cosmetics industry.

[18] . 13. The method according to item 12 above, for preparing a viscous mixture for use as a pharmaceutical excipient.

[19] . 2. Use of the terpolymer according to item 1 for enhancing oil recovery by injecting the aqueous solution containing the terpolymer at a concentration of 0.01 to 5% by weight into a mineral oil deposit through at least one injection well, and removing crude oil from the deposit through at least one production well.

[20] . 10. Use of the terpolymer according to item 1 above for adjusting the viscosity of cosmetic preparations.

[21] . 2. Use of the terpolymer according to item 1 above for adjusting the viscosity of a pharmaceutical excipient or pharmaceutical formulation.

[22] . 10. Use of the terpolymer according to item 1 above as a retention aid for incorporating fine fibers and pigments and as a dry strength agent in papermaking.

[23] . 2. Use of the terpolymer according to item 1 above as a flocculant through charge neutralization and particle bridging in the treatment of water, wastewater or for the removal of unwanted impurities from solutions.

Claims

1. below: i. a water-soluble monoethylenically unsaturated group-containing monomer A; ii. an ionic water-soluble monoethylenically unsaturated group-containing monomer C; iii. Monomer B having a monoethylenically unsaturated monomer, and iv) Iniferters initiated by light with wavelengths between 250 and 400 nm 1. A terpolymer resulting from the aqueous polymerization of a mixture of The monomer A is R １ -(HC=CH)-(C=O)-OR ２ or R １ -(HC=CH)-(C=O)-N(R ３ ) (R ４ ) wherein: R １ is H, R ２ is a residue obtained by removing a hydrogen atom bonded to a carbon atom from methyl, ethyl, epoxymethyl, or methanol, a residue obtained by removing a hydrogen atom bonded to a carbon atom from ethanol, N,N-dimethylaminoethyl, or a residue obtained by removing a hydrogen atom bonded to a carbon atom from PEG (having a molecular weight of 50 to 1000 g / mol), R ３ is H, methyl, or ethyl; R ４ is H, methyl, ethyl, isopropyl, or a residue obtained by removing a hydrogen atom bonded to a carbon atom from propan-2-ol, The monomer B may be any of the following monomers and mixtures thereof: １ -(HC=CH)-(C=O)-N(R ６ ) (R ７ ) or R １ -(HC=CH)-(C=O)-R ８ wherein: R １ is H or methyl, R ６ is poly(ethylene glycol) ｎ (n is 2 to 20 units) by removing a hydrogen atom bonded to a carbon atom, or a residue obtained by removing a hydrogen atom bonded to a carbon atom from a PEGylated hydrocarbon (wherein the hydrocarbon is an aromatic group having a linear or branched alkyl chain of 4 to 20 carbon atoms in length), R ７ is poly(ethylene glycol) ｎ (n is 2 to 20 units) by removing a hydrogen atom bonded to a carbon atom, or a residue obtained by removing a hydrogen atom bonded to a carbon atom from a PEGylated hydrocarbon (wherein the hydrocarbon is an aromatic group having a linear or branched alkyl chain of 4 to 20 carbon atoms in length), R ８ is poly(ethylene glycol) ｎ (n is 2 to 20 units) by removing a hydrogen atom bonded to a carbon atom, or a residue obtained by removing a hydrogen atom bonded to a carbon atom from a PEGylated hydrocarbon (wherein the hydrocarbon is an aromatic group having a linear or branched alkyl chain of 4 to 20 carbon atoms in length), However, the monomer B is not the same as the monomer A, The monomer C may be any of the following monomers and mixtures thereof: １ -(HC=CH)-(C=O)-OR ９ or R ３ -(HC=CH)-(C=O)-N(R １０ ) (R １１ ) wherein: R １ is H or methyl, R ３ is H, methyl or ethyl, R ９ is H, Na ＋ , NH4 ＋ or a residue obtained by removing a hydrogen atom bonded to a carbon atom from sodium salt or neutral 2-amino-2-methylpropane-1-sulfonic acid, R １０ H, O － , OH or NH4 ＋ and R １１ Yes, O － , OH, NH4 ＋ , or -C(CH ３ ) ２ CH ２ SO ３ H or -C(CH ３ ) ２ CH ２ SO ３ － Na ＋ and However, the monomer C is not the same as the monomer A and is not the same as the monomer B, The iniferter is R １’ -(C=S)-S-Z １ or R ２’ -S-(C=S)-S-Z ２ (In the formula, R １’ is a residue obtained by removing a hydrogen atom bonded to a carbon atom from methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, t-butoxy, benzyl, phenyl, or N-methylaniline, Z １ is a residue obtained by removing a hydrogen atom bonded to a carbon atom from propanoic acid, a residue obtained by removing a hydrogen atom bonded to a carbon atom from propanoate, phenylpropan-2-yl, cyanomethyl, cyanopropan-2-yl, R ２’ is a residue obtained by removing a hydrogen atom bonded to a carbon atom (other than the carbon atom of —CN) from a straight or branched alkyl chain (carbon length of C1 to C12), benzyl, phenyl, isobutyronitrile, a residue obtained by removing a hydrogen atom bonded to a carbon atom from propanoate, a residue obtained by removing a hydrogen atom bonded to a carbon atom from propanoic acid, a residue obtained by removing a hydrogen atom bonded to a carbon atom from benzyl isobutyrate, or a residue obtained by removing a hydrogen atom bonded to a carbon atom from 2-(pyridin-2-yldisulfanyl)ethylpropionate; Z ２ is a residue obtained by removing a hydrogen atom bonded to a carbon atom from propanoate, a residue obtained by removing a hydrogen atom bonded to a carbon atom from propanoic acid, a residue obtained by removing a hydrogen atom bonded to a carbon atom from methyl, ethyl, propyl, butyl, pentyl, hexyl, phenyl, benzyl, or benzyl isobutyrate, or a residue obtained by removing a hydrogen atom bonded to a carbon atom from PEGylated 2-cyanopropanoic acid; the terpolymer has a viscosity of 23 cP or greater in saline (2 wt%); The viscosity here was measured by diluting the terpolymer with fresh water to a concentration of 3.5 g / L to prepare a fresh water solution, adding 2% by weight of seawater to this fresh water solution to prepare a salt water solution, and measuring the viscosity at 0.1 s using a rotational viscometer. －１ is a value obtained by measuring the viscosity of a salt solution at a shear rate of Terpolymer.

2. Weight average molecular weight ≧1.0×10 ６ 10. The terpolymer of claim 1 having a molecular weight of 1000 or more, preferably 1000 or more, and more preferably 1000 or more.

3. 2. The terpolymer of claim 1, wherein said monomer A is present in an amount of 25.0 to 74.9 mol %, said monomer C is present in an amount of 25.0 to 74.9 mol %, and said monomer B is present in an amount of 0.1 to 5.0 mol %, each based on the total molar amount of all components in the copolymer.

4. 1. An aqueous process for the preparation of a terpolymer comprising the following steps: i. The following groups: a water-soluble monoethylenically unsaturated group-containing monomer A; an ionic water-soluble monoethylenically unsaturated group-containing monomer C, and Monomer B having a monoethylenically unsaturated monomer A mixture of R １’ -(C=S)-S-Z １ or R ２’ -S-(C=S)-S-Z ２ (In the formula, R １’ is a residue obtained by removing a hydrogen atom bonded to a carbon atom from methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, t-butoxy, benzyl, phenyl, or N-methylaniline, Z １ is a residue obtained by removing a hydrogen atom bonded to a carbon atom from propanoic acid, a residue obtained by removing a hydrogen atom bonded to a carbon atom from propanoate, phenylpropan-2-yl, cyanomethyl, cyanopropan-2-yl, R ２’ is a residue obtained by removing a hydrogen atom bonded to a carbon atom (other than the carbon atom of —CN) from a straight or branched alkyl chain (carbon length of C1 to C12), benzyl, phenyl, isobutyronitrile, a residue obtained by removing a hydrogen atom bonded to a carbon atom from propanoate, a residue obtained by removing a hydrogen atom bonded to a carbon atom from propanoic acid, a residue obtained by removing a hydrogen atom bonded to a carbon atom from benzyl isobutyrate, or a residue obtained by removing a hydrogen atom bonded to a carbon atom from 2-(pyridin-2-yldisulfanyl)ethylpropionate; Z ２ is a residue obtained by removing a hydrogen atom bonded to a carbon atom from propanoate, a residue obtained by removing a hydrogen atom bonded to a carbon atom from propanoic acid, a residue obtained by removing a hydrogen atom bonded to a carbon atom from methyl, ethyl, propyl, butyl, pentyl, hexyl, phenyl, benzyl, or benzyl isobutyrate, or a residue obtained by removing a hydrogen atom bonded to a carbon atom from PEGylated 2-cyanopropanoic acid, to form a reaction mixture; ii. sparging the reaction mixture with an inert gas; and iii. Initiating the iniferter with light of wavelength between 250 and 400 nm. Including, wherein the monomer A is R １ -(HC=CH)-(C=O)-OR ２ or R １ -(HC=CH)-(C=O)-N(R ３ ) (R ４ ) wherein: R １ is H, R ２ is a residue obtained by removing a hydrogen atom bonded to a carbon atom from methyl, ethyl, epoxymethyl, or methanol, a residue obtained by removing a hydrogen atom bonded to a carbon atom from ethanol, N,N-dimethylaminoethyl, or a residue obtained by removing a hydrogen atom bonded to a carbon atom from PEG (having a molecular weight of 50 to 1000 g / mol), R ３ is H, methyl, or ethyl; R ４ is H, methyl, ethyl, isopropyl, or a residue obtained by removing a hydrogen atom bonded to a carbon atom from propan-2-ol, The monomer B may be any of the following monomers and mixtures thereof: １ -(HC=CH)-(C=O)-N(R ６ ) (R ７ ) or R １ -(HC=CH)-(C=O)-R ８ wherein: R １ is H or methyl, R ６ is poly(ethylene glycol) ｎ (n is 2 to 20 units) by removing a hydrogen atom bonded to a carbon atom, or a residue obtained by removing a hydrogen atom bonded to a carbon atom from a PEGylated hydrocarbon (wherein the hydrocarbon is an aromatic group having a linear or branched alkyl chain of 4 to 20 carbon atoms in length), R ７ is poly(ethylene glycol) ｎ (n is 2 to 20 units) by removing a hydrogen atom bonded to a carbon atom, or a residue obtained by removing a hydrogen atom bonded to a carbon atom from a PEGylated hydrocarbon (wherein the hydrocarbon is an aromatic group having a linear or branched alkyl chain of 4 to 20 carbon atoms in length), R ８ is poly(ethylene glycol) ｎ (n is 2 to 20 units) by removing a hydrogen atom bonded to a carbon atom, or a residue obtained by removing a hydrogen atom bonded to a carbon atom from a PEGylated hydrocarbon (wherein the hydrocarbon is an aromatic group having a linear or branched alkyl chain of 4 to 20 carbon atoms in length), However, the monomer B is not the same as the monomer A, The monomer C may be any of the following monomers and mixtures thereof: １ -(HC=CH)-(C=O)-OR ９ or R ３ -(HC=CH)-(C=O)-N(R １０ ) (R １１ ) wherein: R １ is H or methyl, R ３ is H, methyl or ethyl, R ９ is H, Na ＋ , NH4 ＋ or a residue obtained by removing a hydrogen atom bonded to a carbon atom from sodium salt or neutral 2-amino-2-methylpropane-1-sulfonic acid, R １０ H, O － , OH or NH4 ＋ and R １１ Yes, O － , OH, NH4 ＋ , or -C(CH ３ ) ２ CH ２ SO ３ H or -C(CH ３ ) ２ CH ２ SO ３ － Na ＋ and However, the monomer C is not the same as the monomer A and is not the same as the monomer B, the terpolymer has a viscosity of 23 cP or greater in saline (2 wt%); The viscosity here was measured by diluting the terpolymer with fresh water to a concentration of 3.5 g / L to prepare a fresh water solution, adding 2% by weight of seawater to this fresh water solution to prepare a salt water solution, and measuring the viscosity at 0.1 s using a rotational viscometer. －１ is a value obtained by measuring the viscosity of a salt solution at a shear rate of Aqueous process.

5. 5. The aqueous process of claim 4, wherein the preparation is carried out in a solvent system consisting of water and a polar protic or polar aprotic solvent, the ratio of water to polar protic or polar aprotic solvent ranging from 100 / 0 to 51 / 49.

6. 5. The aqueous process of claim 4, wherein the terpolymer is produced in the form of a gel.

7. 10. A method comprising thickening an aqueous solution by adding to said aqueous solution a sufficient amount of the terpolymer of claim 1 to thicken said aqueous solution.

8. 8. The method of claim 7, wherein the solution is used to develop or exploit underground mineral oil or natural gas deposits.

9. 8. The method of claim 7, wherein the solution is used to transport a proppant selected from the group consisting of sand, treated sand, and engineered ceramic materials.

10. 10. The method of claim 9, wherein the proppant functions to hold open an induced hydraulic fracture.

11. 10. The method of claim 7 for enhancing oil recovery by injecting said aqueous solution at a concentration of 0.01 to 5 wt% into a mineral oil deposit through at least one injection well and removing crude oil from said deposit through at least one production well.

12. 8. The method of claim 7 for increasing the viscosity of a mixture for use in the cosmetics industry.

13. 10. The method of claim 7 for making a viscous mixture for use as a pharmaceutical excipient.

14. 10. The terpolymer of claim 1, wherein the aqueous solution comprising the terpolymer at a concentration of 0.01 to 5 wt. % is used to enhance oil recovery by injecting the aqueous solution into a mineral oil deposit through at least one injection well and for removing crude oil from the deposit through at least one production well.

15. 10. The terpolymer according to claim 1, used to adjust the viscosity of cosmetic preparations.

16. 10. The terpolymer of claim 1 used to adjust the viscosity of a pharmaceutical excipient or pharmaceutical formulation.

17. 10. The terpolymer of claim 1 used as a retention aid for incorporating fines and pigments and as a dry strength agent in papermaking.

18. 10. The terpolymer of claim 1 used as a flocculant through charge neutralization and particle bridging in the treatment of water, wastewater, or for the removal of unwanted impurities from solutions.

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