METHOD OF PREPARING ALDEHYDE-FUNCTIONALIZED POLYMERS
20230128251 · 2023-04-27
Inventors
- HERMAN MARK GRIMM (Eagan, MN, US)
- Mei Liu (Eagan, MN, US)
- David Jordan (Eagan, MN, US)
- Nathan Jones (Eagan, MN, US)
Cpc classification
C08F2810/10
CHEMISTRY; METALLURGY
International classification
D21H17/37
TEXTILES; PAPER
Abstract
A method is provided for generating aldehyde-functionalized polymers such as GPAM, wherein progress of the aldehyde-functionalized polymer formation is monitored by measuring viscosity using an online viscometer. A method is also provided for enhancing paper strength, said method comprising generating an aldehyde-functionalized polymer, such as GPAM, according to the present disclosure, and combining said aldehyde-functionalized polymer with a fiber slurry or applying it to a paper sheet.
Claims
1. A method of making GPAM, said method comprising: (a) combining at least a polyacrylamide and glyoxal to obtain a reaction solution; and (b) quenching the reaction by adjusting the pH of the reaction solution to a value in a range from about 2 to about 6 to obtain said GPAM; wherein progress of the reaction is monitored by measuring the viscosity of the reaction solution using an online viscosity meter.
2. The method of claim 1, wherein said GPAM has a weight average molecular weight of from about 10,000 g/mole to 10,000,000 g/mole.
3. The method of claim 1, wherein said GPAM has a glyoxal to acrylamide (G/A ratio) of about 0.05:1 to about 20:1.
4. The method of claim 1, wherein the progress of said reaction is monitored by continuously measuring the viscosity of said reaction solution, optionally with feedback control.
5. The method of claim 1, wherein the online viscosity meter comprises: (a) a transducer assembly comprising: (i) at least one flow tube inserted into a pipe, said flow tube having a lumen conducting the reaction solution and said flow tube being clamped at an inlet end and an outlet end so as to be capable of vibrating; (ii) an electromechanical excitation arrangement; and (iii) a sensor arrangement; and (b) meter electronics.
6. The method of claim 1, wherein the reaction is quenched when the viscosity of the reaction solution compared to its initial viscosity has increased more than 100%.
7. The method of claim 1, wherein the pH of the reaction in step (a) is maintained in a range of from about 8 to about 9 by adding a caustic solution wherein said caustic solution is optionally further diluted with water.
8. The method of claim 1, wherein in step (b) said quenching comprises adding an organic acid to the reaction solution.
9. The method of claim 3, wherein said GPAM has a glyoxal to acrylamide (G/A ratio) of in the range of about 0.4:1 to about 20:1.
10. The method of claim 1, wherein said polyacrylamide is a copolymer of acrylamide/DADMAC.
11. The method of claim 10, wherein said copolymer is about 1-30 mole % DADMAC and about 70-99 mole % acrylamide.
12. The method of claim 1, wherein said viscosity meter is an open flow tube viscometer.
13. The method of claim 1, wherein said viscosity meter comprises a measuring system having at least one measuring tube, which in measurement operation is filled with the reaction solution, or through which the reaction solution is flowing, and which has at least one tube section excitable to execute oscillations, an exciter system for exciting at least two wanted oscillation modes of different frequencies, at each of which at least one of the tube sections is excited to execute oscillations, especially resonant oscillations, a sensing system, which is embodied in such a manner that it determines for the wanted oscillation modes excited in measurement operation, in each case, a frequency and a damping, especially a frequency, an amplitude and a damping, of a resulting oscillation of at least one tube section excited to execute oscillations of one of the wanted oscillation modes, and an evaluation system, which is embodied in such a manner that it determines, based on calibration data stored in a memory for the individual wanted oscillation modes excited in measurement operation, in each case, based on an excitation determined frequency and damping, especially frequency, amplitude and damping, of the resulting oscillation a shear rate value and a viscosity measured value, wherein the viscosity measured value corresponds to the dynamic viscosity of the GPAM at a static shear rate corresponding to the shear rate value.
14. A method of generating aldehyde-functionalized polymer, said method comprising: (a) combining at least a polymer comprising at least one amide group or amino group and an aldehyde to obtain a reaction solution; and (b) quenching the reaction by adjusting the pH of the reaction solution to a value in a range from about 2 to about 6 to obtain said aldehyde-functionalized polymer; wherein progress of the reaction is monitored by measuring the viscosity of the reaction solution using an online viscosity meter.
15. The method of claim 14, wherein said aldehyde is chosen from formaldehyde, paraformaldehyde, and glutaraldehyde.
16. The method according to claim 15, wherein said method further comprises contacting said aldehyde-functionalized polymer with a fiber slurry, or with a paper sheet.
17. A GPAM composition comprising GPAM prepared according to a method of claim 1, wherein said GPAM has a weight average molecular weight of from about 10,000 g/mole to 10,000,000 g/mole and wherein said GPAM has a glyoxal to acrylamide (G/A ratio) in the range of about 0.05:1 to about 20:1.
Description
BRIEF DESCRIPTION OF THE FIGURES
[0109]
[0110]
[0111]
[0112]
PREPARATION
[0113] One aspect of the invention pertains to a method of making GPAM, said method comprising: [0114] (a) initiating a crosslinking reaction to generate GPAM by combining at least a polyacrylamide and glyoxal to obtain a reaction solution; and [0115] (b) quenching the reaction of step (a) by adjusting the pH of the reaction to a value in a range from about 2 to about 6 (or about 4 to about 6), once a target viscosity of the GPAM is met; [0116] wherein the progress of GPAM formation is monitored by measuring the viscosity of the reaction solution via feedback loop from an online viscosity meter.
[0117] In some embodiments, step (a) comprises combining said polyacrylamide with water to obtain a mixture, and adding said glyoxal to the mixture to obtain said reaction solution.
[0118] In further embodiments, step (a) comprises combining said glyoxal with water to obtain a mixture and adding said polyacrylamide to the mixture of step (i) to obtain said reaction solution.
[0119] In some embodiments, step (a) comprises adjusting the temperature to between about 65-85 deg F. For example, the temperature may be adjusted between about 60-80 deg F., between about 70 to about 75 deg F., or to about 75 deg F.
[0120] In some embodiments, step (a) followed by step (b) may be repeated at least twice. For example, step (a) followed by step (b) may be repeated three times, four times, etc. The reaction vessel in which steps (a) and (b) are carried out may be cleaneded in between each cycle (i.e., step (a) followed by step (b).
[0121] In some embodiments, the adjustment of the pH in step (b) may be monitored in real time. This may be done by the use one pH meter, or in some instances 2 or more pH meters.
[0122] A further aspect of the invention pertains to a GPAM composition comprising GPAM prepared according to the method of preparing GPAM as disclosed herein, wherein said GPAM has a weight average molecular weight of from about 10,000 g/mole to 10,000,000 g/mole and wherein said GPAM has a glyoxal to acrylamide (G/A ratio) in the range of about 0.4 to about 1 to about 20 to about 1 or in the range of 0.4:1 to 20:1, or 0.4:1 or 0.8:1.
[0123] A further embodiment of the invention pertains to a GPAM composition prepared according to invention, wherein said GPAM has a weight average molecular weight of from about 10,000 g/mole to 10,000,000 g/mole; 10,000 g/mole to 7,000,000 g/mole; 10,000 g/mole to 5,000,000 g/mole; 3,000,000 g/mole to 4,000,000 g/mole; and 3,000,000 g/mole to 4,000,000 g/mole; wherein said GPAM has a glyoxal to acrylamide (G/A ratio) of about 0.4 to about 1 to about 20 to about 1.
[0124] A yet further aspect of the invention pertains to a method of generating aldehyde-functionalized polymer, said method comprising: [0125] (a) initiating a crosslinking reaction to generate said aldehyde-functionalized polymer by combining at least a polymer comprising at least one amide group or amino group and an aldehyde to obtain a reaction solution; and [0126] (b) quenching the reaction of step (a) by adjusting the pH to a value in a range from about 4 to about 6, once the target viscosity of said aldehyde-functionalized polymer is met, [0127] wherein the progress of formation the aldehyde-functionalized polymer is monitored by measuring the viscosity of the reaction solution via feedback loop from an online viscosity meter.
[0128] A further embodiment of the invention pertains to an aldehyde-functionalized polymer composition is prepared according to invention, wherein said aldehyde-functionalized polymer has a weight average molecular weight of from about 10,000 g/mole to 10,000,000 g/mole; 10,000 g/mole to 7,000,000 g/mole; 10,000 g/mole to 5,000,000 g/mole; 1,000,000 g/mole to 4,000,000 g/mole; 3,000,000 g/mole to 4,000,000 g/mole; and 3,000,000 g/mole to 4,000,000 g/mole; wherein said aldehyde-functionalized polymer has an aldehyde to acrylamide (A/A ratio) of about 0.4 to about 1 to about 20 to about 1.
[0129] In a further embodiment, the method according to the present disclosure includes measuring the viscosity of the reaction mixture continuously in real time.
[0130] In a further embodiment, the method according to the present disclosure includes continuously monitoring the viscosity the reaction mixture with an on-line flow-through viscometer, wherein said viscometer does not require “grab sampling” or “spot checking”.
[0131] In some embodiments, the method according to the present disclosure includes continuously sending a viscosity value from an online viscometer to a feedback loop for in-line control of the pH of step (a) and/or (b).
[0132] In a further embodiment, the method according to the present disclosure includes continuously monitoring the reaction mixture with an in-line open flow-through type viscometer.
[0133] In some embodiments, the method according to the present disclosure includes continuously sending a viscosity value from a viscometer to a feedback loop for in-line control of the pH of step (a).
[0134] In a further embodiment, the method according to the present disclosure includes, prior to meeting the target viscosity, maintaining the pH of the reaction mixture in a range of from about 8 to about 9 by adding a caustic solution, and optionally further diluting the caustic solution with water.
[0135] In a further embodiment, the method according to the present disclosure includes adjusting quench the reaction of step (a) by adding an organic acid such as citric acid.
[0136] In a further embodiment, the method according to the present disclosure includes preparing GPAM at paper production site (i.e., “onsite”) in a semi-batch, or a full batch.
[0137] In a further embodiment, the method according to the present disclosure includes adjusting automatically using inline pH control (via addition of acid) once the target viscosity of the aldehyde functionalized polymer (e.g., GPAM) is reached.
[0138] In a further embodiment, the method according to the present disclosure includes wherein the GPAM has a shelf-life in a range of from about 24 hours to about 2.5 months.
[0139] In a further embodiment, the method according to the present disclosure includes wherein steps (a) and/or (b) is conducted at a paper production site.
[0140] In some embodiments, said polyacrylamide is obtained by combining at least water, a copolymer of acrylamide and an ionic monomer. In a further embodiment, the method according to the present disclosure includes wherein the ionic monomer in the copolymer of acrylamide and an ionic monomer is a cationic, anionic or zwitterionic monomer.
[0141] Representative anionic monomers include acrylic acid, and its salts, including, but not limited to sodium acrylate, and ammonium acrylate, methacrylic acid, and its salts, including, but not limited to sodium methacrylate, and ammonium methacrylate, 2-acrylamido-2-methylpropanesulfonic acid, the sodium salt of AMPS, sodium vinyl sulfonate, styrene sulfonate, maleic acid, and its salts, including, but not limited to the sodium salt, and ammonium salt, sulfonate itaconate, sulfopropyl acrylate or methacrylate or other water-soluble forms of these or other polymerizable carboxylic or sulphonic acids. Sulfomethylated acrylamide, allyl sulfonate, sodium vinyl sulfonate, itaconic acid, acrylamidomethylbutanoic acid, fumaric acid, vinylphosphonic acid, vinylsulfonic acid, allylphosphonic acid, sulfomethylated acrylamide, phosphonomethylated acrylamide, and the like.
[0142] Representative cationic monomers include dialkylaminoalkyl acrylates and methacrylates and their quaternary or acid salts, including, but not limited to, dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate methyl sulfate quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl acrylate sulfuric acid salt, dimethylaminoethyl acrylate hydrochloric acid salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfuric acid salt, dimethylaminoethyl methacrylate hydrochloric acid salt, dialkylaminoalkylacrylamides or methacrylamides and their quaternary or acid salts such as acrylamidopropyltrimethylammonium chloride, dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, methacrylarnidopropyl trimethylammonium chloride, dimethylaminopropyl acrylamide methyl sulfate quaternary salt, dimethylaminopropyl acrylamide sulfuric acid salt, dimethylaminopropyl acrylamide hydrochloric acid salt, methacrylamidopropyltrimethylammonium chloride, dimethylaminopropyl methacrylamide methyl sulfate quaternary salt, dimethylaminopropyl methacrylamide sulfuric acid salt, dimethylaminopropyl methacrylamide hydrochloric acid salt, diethylaminoethylacrylate, diethylaminoethylmethacrylate, diallyldiethylammonium chloride, diallyldimethylammonium chloride, and the like.
[0143] Representative zwitterionic monomers include N,N-dimethyl-N-acryloyloxyethyl-N-(3-sulfopropyl)-ammonium betaine, N,N-dimethyl-N-acrylamidopropyl-N-(2-carboxymethyl)-ammonium betaine, N,N-dimethyl-N-acrylamidopropyl-N-(3-sulfopropyl)-ammonium betaine, N,N-dimethyl-N-acrylamidopropyl-N-(2-carboxymethyl)-ammonium betaine, 2-(methylthio)ethyl methacryloyl-S-(sulfopropyl)-sulfonium betaine, 2-[(2-acryloylethyl)dimethylammonio]ethyl 2-methyl phosphate, 2-(acryloyloxyethyl)-2′-(trimethylammonium)ethyl phosphate, [(2-acryloylethyl)dimethylammonio]methyl phosphonic acid, 2-methacryloyloxyethyl phosphorylcholine (MPC), 2-[(3-acrylamidopropyl)dimethylammonio]ethyl 2′-isopropyl phosphate (AAPI), 1-vinyl-3-(3-sulfopropyl)imidazolium hydroxide, (2-acryloxyethyl) carboxymethyl methylsulfonium chloride, 1-(3-sulfopropyl)-2-vinylpyridinium betaine, N-(4-sulfobutyl)-N-methyl-N, N-diallylamine ammonium betaine (MDABS), N,N-diallyl-N-methyl-N-(2-sulfoethyl)ammonium betaine, and the like.
[0144] In certain embodiments, the amino groups, amide groups, or combination of the amino and amide groups thereof are mono-reacted and di-reacted at a ratio of at least about 3 to 1 and GPAM has a weight average molecular weight of from about 10,000 g/mole to about 10,000,000 g/mole; from about 50,000 g/mole to about 5,000,000 g/mole; from about 100,000 g/mole to about 3,000,000 g/mole; from about 200,000 g/mole to about 1,000,000 g/mole; from about 300,000 g/mole to about 1,000,000 g/mole; from about 500,000 g/mole to about 1,000,000 g/mole.
[0145] In certain embodiments, the amino groups, amide groups, or combination of the amino and amide groups thereof are mono-reacted and di-reacted at a ratio of at least about 4 to 1 and the GPAM has a weight average molecular weight of from about 10,000 g/mole to about 10,000,000 g/mole; from about 50,000 g/mole to about 5,000,000 g/mole; from about 100,000 g/mole to about 3,000,000 g/mole; from about 200,000 g/mole to about 1,000,000 g/mole; from about 300,000 g/mole to about 1,000,000 g/mole; from about 500,000 g/mole to about 1,000,000 g/mole.
[0146] In certain embodiments, the GPAM prepared using the methods disclosed herein is a glyoxalated DADMAC/acrylamide polymer. In certain embodiments, acrylamide/DADMAC copolymer (e.g., 95/5 mole % acrylamide/DADMAC copolymer) may be used to prepare the GPAM of the invention. The 95/5 mole % acrylamide/DADMAC copolymer may be prepared according to the method described in US Patent Application Publication No. 2005/016118 (which is incorporated by reference to the extent to it disclosure does not conflict with the description herein)(see Example 1). U.S. Pat. Nos. 10,006,170 and 8,894,817 are also incorporated by reference to the extent to their disclosure do not conflict with the description herein.
[0147] Mono-reacted amide or amine refers to a polymer formed when one glyoxal reacts with one amide or amine, and di-reacted amide or amine refers to a polymer formed when one glyoxal reacts with two amides or amines.
[0148] The aldehyde function polymers of the present disclosure (including GPAM) may comprise amino groups, amide groups, or both amino and amide groups substituted with an aldehyde in a mono-reacted to di-reacted amide ratio of at least about 1.5 to 1. Without wishing to be bound by any particular theory, it is believed that the mono-reacted aldehyde in the polymer is partially responsible for the observed enhancement of paper strength in the presence of the aldehyde-functionalized polymer. Thus, it is believed that the mono-reacted species (e.g., species having a free aldehyde) is responsible for the increased paper strength because, unlike the di-reacted species, the mono-reacted species can form a covalent bond with cellulose fiber.
[0149] In certain embodiments, the aldehyde-functionalized polymer (such as GPAM) of the invention comprises amino groups, amide groups, or a combination of amino and amide groups that are mono-reacted and di-reacted with aldehyde at a ratio of at least about 1.5 to 1. In certain embodiments, the GPAM comprises amino groups, amide groups, or a combination of amino and amide groups that are mono-reacted and di-reacted with glyoxal at a ratio of at least about 3 to 1. Thus, in certain embodiments, the GPAM of the invention comprises amino groups, amide groups, or both amino and amide groups that are mono-reacted and di-reacted with glyoxal at a ratio of at least about 3 to 1, at least about 3.5 to 1, at least about 4 to 1, at least about 4.5 to 1, at least about 5 to 1, at least about 5.5 to 1, or at least about 6 to 1. In certain embodiments, the GPAM comprises amino groups, amide groups, or a combination of amino and amide groups that are mono-reacted and di-reacted with glyoxal at a ratio of greater than about 3 to 1. In certain embodiments, the GPAM of the invention comprises amino groups, amide groups, or a combination of amino and amide groups that are mono-reacted and di-reacted with glyoxal at a ratio of at least about 3.5 to 1. In certain embodiments, the GPAM of the invention comprises amino groups, amide groups, or a combination of amino and amide groups that are mono-reacted and di-reacted with glyoxal at a ratio of at least about 4 to 1.
[0150] In certain embodiments, the GPAM of the invention comprises amino groups, amide groups, or a combination of amino and amide groups that are mono-reacted and di-reacted with glyoxal at a ratio of from about 3:1 to about 20:1. Thus, in certain embodiments, the GPAM of the invention comprises amino groups, amide groups, or a combination of amino and amide groups that are mono-reacted and di-reacted with glyoxal at a ratio of from about 3:1 to about 20:1, from about 3.5:1 to about 20:1, from about 4:1 to about 20:1, from about 4.5:1 to about 20:1, from about 5:1 to about 20:1, from about 5.5:1 to about 20:1, or from about 6:1 to about 20:1.
[0151] In certain embodiments, the composition comprises mono-reacted glyoxal and di-reacted glyoxal at a ratio of at least about 7 to 1, at least about 8 to 1, at least about 9 to 1, at least about 10 to 1, at least about 11 to 1, or at least about 12 to 1. In certain embodiments, the composition comprises mono-reacted glyoxal and di-reacted glyoxal at a ratio of from about 9:1 to about 50:1.
[0152] The GPAM of the invention may comprise any amount of amino groups, amide groups, and combinations that are mono-reacted. In certain embodiments, at least about 10 mole percent of the amino groups, amide groups, and combinations thereof are mono-reacted with at least one aldehyde. In certain embodiments, at least about 15 mole percent of the amino groups, amide groups, and combinations thereof are mono-reacted with at least one aldehyde. In certain embodiments, at least about 20 mole percent of the amino groups, amide groups, and combinations thereof are mono-reacted with at least one aldehyde.
[0153] In certain embodiments, the GPAM of the invention is formed by functionalizing an acrylamide copolymer comprising amino groups, amide groups, or a combination of amino and amide groups with one or more glyoxal wherein the glyoxal reacts with at least about 15 mole percent of the amino groups, amide groups, or combinations thereof. Thus, in certain embodiments, GPAM is formed by reacting at least a copolymer of acrylamide and an ionic monomer, which may comprise amino and/or amide groups with glyoxal wherein the glyoxal reacts with at least about 15 mole percent of the amino and/or amide groups, at least about 16 mole percent of the amino and/or amide groups, at least about 17 mole percent of the amino and/or amide groups, at least about 18 mole percent of the amino and/or amide groups, at least about 19 mole percent of the amino and/or amide groups, at least about 20 mole percent of the amino and/or amide groups, at least about 22 mole percent of the amino and/or amide groups, at least about 24 mole percent of the amino and/or amide groups, at least about 25 mole percent of the amino and/or amide groups, at least about 30 mole percent of the amino and/or amide groups, at least about 35 mole percent of the amino and/or amide groups, at least about 40 mole percent of the amino and/or amide groups, at least about 45 mole percent of the amino and/or amide groups, or at least about 50 mole percent of the amino and/or amide groups.
[0154] In certain embodiments, the method comprises combining at least a polyacrylamide and glyoxal to obtain a reaction solution; wherein the polyacrylamide has a weight average molecular weight of from about 7,000 g/mole to about 50,000 g/mole (about 10,000 g/mole to about 45,000 g/mole; about 15,000 g/mole to about 40,000 g/mole; about 20,000 g/mole to about 30,000 g/mole; about 7,000 g/mole to about 30,000 g/mole); and wherein said reaction is quenched when the viscosity of the reaction solution is in the range of about 12 cp to about 40 cP (about 15 cp to about 40 cP; about 18 cp to about 30 cP; about 20 cp to about 40 cP; about 25 cp to about 40 cP; about 12 cp to about 30 cP).
[0155] In certain embodiments, the method comprises combining at least a polyacrylamide and glyoxal to obtain a reaction solution; wherein the polyacrylamide has a weight average molecular weight of from about 50,000 g/mole to about 200,000 g/mole (about 50,000 g/mole to about 150,000 g/mole; about 75,000 g/mole to about 200,000 g/mole; about 80,000 g/mole to about 180,000 g/mole; about 100,000 g/mole to about 200,000 g/mole); and wherein said reaction is quenched when the viscosity of the reaction solution is in the range of about 20 cp to about 1000 cP (about 50 cp to about 500 cP; about 100 cp to about 800 cP; about 150 cp to about 600 cP; about 75 cp to about 400 cP; about 200 cp to about 500 cP).
[0156] In certain embodiments, the GPAM of the invention has a weight average molecular weight of from about 10,000 g/mole to about 10,00,000 g/mole, from about 10,000 g/mole to about 7,000,000 g/mole, from about 10,000 g/mole to about 5,000,000 g/mole, 1,000,000 g/mole to about 10,000,000 g/mole, from about 1,000,000 g/mole to about 5,000,000 g/mole from about 3,000,000 g/mole to about 4,000,000 g/mole, or from about 3,000,000 g/mole to about 5,000,000 g/mole.
[0157] In certain embodiments, the polymerization and/or post polymerization reaction conditions are selected such that the resulting polymer comprising amino and/or amide groups has a molecular weight of from about 1,000 g/mole to about 10,000,000 g/mole.
[0158] In some embodiments, GPAM may be prepared using manufacturing process as outlined in
[0164] During the reaction, pH may be maintained between about 8 to about 9 by relying on a caustic pump running in tandem with dilution water using in-line pH control. When the desired viscosity is met, the reaction is quenched, and an acid pump (such as a citric acid pump) is started and the pH of the resulting solution is lowered to a range of from about 4 to about 6, depending on the level of shelf-life needed.
[0165] In
Viscometer
[0166] It is particularly advantageous to monitor the viscosity continuously and in real time, to enable a feedback control system for the reaction. The reaction time of the method disclosed herein can be controlled by adjusting the pH level, and the adjustment of pH can be brought under automation control by including the continuous real time measurement of the viscosity of the reaction mixture. Of the various viscometers available, some are more suitable than others for continuous real time measurement of viscosity. Viscometers with spindle arrangement are not suitable (for example, a BROOKFIELD LV series viscometer, with UL adapter—see U.S. Pat. No. 8,920,606; see also, U.S. Patent Publication No. 2005/0161181). On the other hand, “open flow through type” in-line viscometers are better alternatives, e.g., viscometers that operate based concentric cylinder geometry (Couette type) providing viscosity measurements at defined shear conditions (i.e., Couette viscometers), such a Brookfield TT-100 Viscometer (found at e.g., https://www.brookfieldengineering.com/products/viscometers/in-line-process-viscometers/tt-100-viscometer), which may be used for monitoring the progress of formation of aldehyde functionalized polymer (e.g., GPAM) in step (a). Additionally, viscometers operating with an open flow tube such as Proline Promass 83I (E+H) may be suitable for monitoring the progress of formation of aldehyde functionalized polymer (e.g., GPAM) in step (a).
[0167] Another type of viscometer that may be used for monitoring the progress of formation of aldehyde functionalized polymer (e.g., GPAM) in step (a). is a “vibration meter”, which measures vibrational flexing of a flow tube under electromechanical excitation. An example of such a vibration meter is described in U.S. Pat. No. 7,520,162, see e.g., columns 6-9, the disclosure of which is hereby incorporated by reference.
[0168] Measurement of the oscillation modes of flow tube 13 can be analyzed using the meter electronics module, which includes an evaluating circuit which estimates signals from electrodynamic sensors 17 and 18 and from the excitation current i.sub.exc a damping of oscillations of flow tube 13 and which derives a viscosity value representative of the viscosity of the fluid based on said damping being estimated. Additional detail for the functioning of the meter electronics module is described in U.S. Pat. No. 7,520,162, see e.g., columns 6-9.
[0169] Materials especially suited for flow tube 13 are titanium alloys, for example. It is also possible to use other materials commonly employed for such flow tubes, particularly for bent tubes, such as stainless steel or zirconium. Transducer assembly 10 further comprises an electromechanical excitation arrangement 16, which is activated by excitation current i.sub.exc to spatially deflect flow tube 13 from a static position of rest during operation, elastically deforming flow tube 13 with lateral and torsional movement. A sensor arrangement 60 includes velocity-measuring electrodynamic sensors 17 and 18, which serve to sense movements of flow tube 13 as it flexes. Sensor arrangement 60 is connected to a meter electronics module (not shown), for recording and analysis of signals from the sensors, and for delivery of excitation current i.sub.exc to excitation arrangement 16.
[0170] In some embodiments, said online viscosity meter comprises: [0171] (a) a transducer assembly comprising: [0172] (i) at least one flow tube being inserted into a pipe, said flow tube having a lumen conducting the aldehyde functionalized polymer (e.g., GPAM) of the invention and said flow tube being clamped at an inlet end and an outlet end so as to be capable of vibrating; [0173] (ii) an electromechanical excitation arrangement, said excitation arrangement driving said flow tube to oscillate in a bending mode at least partially for producing viscous friction within the fluid; and [0174] (iii) a sensor arrangement, responsive to oscillations of the flow tube, for generating at least one sensor signal, representative of lateral deflections of the flow tube; and [0175] (b) meter electronics comprising: [0176] (i) an excitation circuit which generates an excitation current feeding the excitation arrangement; and [0177] (ii) an evaluating circuit which estimates from said at least one sensor signal and from the excitation current a damping of oscillations of said flow tube and which derives a viscosity value representative of the viscosity of said aldehyde functionalized polymer of the invention based on said damping being estimated.
[0178] In certain embodiments, said online viscosity meter comprises: [0179] (a) a transducer assembly comprising: [0180] (i) at least one flow tube being inserted into the pipe, said flow tube having a lumen conducting the GPAM and said flow tube being clamped at an inlet end and an outlet end so as to be capable of vibrating; [0181] (ii) an electromechanical excitation arrangement, said excitation arrangement driving said flow tube to oscillate in a bending mode at least partially for producing viscous friction within the fluid; and [0182] (iii) a sensor arrangement, responsive to oscillations of the flow tube, for generating at least one sensor signal, representative of lateral deflections of the flow tube; and [0183] (b) meter electronics comprising: [0184] (i) an excitation circuit which generates an excitation current feeding the excitation arrangement; and [0185] (ii) an evaluating circuit which estimates from said at least one sensor signal and from the excitation current a damping of oscillations of said flow tube and which derives a viscosity value representative of the viscosity of said GPAM of the invention based on said damping being estimated.
[0186] Advantageously, there are no parts or protrusions within the flow tube 13 to become fouled with GPAM, should it begin to gel, for example. A recirculating pump can be used for pumping a flow of the GPAM through flow tube 13, enabling continuous real-time measurement of viscosity
[0187] In some embodiments, a viscometer including the transducer assembly of
[0188] In some embodiments, the online viscometer used for the invention may be one that relies on a Coriolis effect and measures oscillating deflections of one or more bent flow tubes is described in U.S. Published Patent Application No. 2020/0166444, which is incorporated herein by reference. In some embodiments, a Coriolis mass flow measuring system (such as those where measuring is based on a torsional movement of a measurement tube) may be used to control reaction time by monitoring the viscosity of GPAM formed. For example, the viscometer that may be used in preparation of GPAM according to the invention may comprise: [0189] a measuring system having at least one measuring tube, which in measurement operation is filled with a fluid (i.e., GPAM) or through which GPAM is flowing, and which has at least one tube section excitable to execute oscillations, an exciter system for exciting at least two wanted oscillation modes of different frequencies, at each of which at least one of the tube sections is excited to execute oscillations, especially resonant oscillations, [0190] a sensing system, which is embodied in such a manner that it determines for the wanted oscillation modes excited in measurement operation, in each case, a frequency and a damping, especially a frequency, an amplitude and a damping, of a resulting oscillation of at least one tube section excited to execute oscillations of one of the wanted oscillation modes, and [0191] an evaluation system, which is embodied in such a manner that it determines, based on calibration data stored in a memory for the individual wanted oscillation modes excited in measurement operation, in each case, based on an excitation determined frequency and damping, especially frequency, amplitude and damping, of the resulting oscillation a shear rate value and a viscosity measured value, wherein the viscosity measured value corresponds to the dynamic viscosity of the GPAM at a static shear rate corresponding to the shear rate value.
[0192] Application
[0193] A further aspect of the invention pertains to a method for enhancing paper strength and press section dewatering of a paper sheet on a paper machine comprising adding to the paper sheet about 0.05 lb/ton to about 20 lb/ton, based on dry fiber, an aqueous composition prepared according to a method of preparing GPAM disclosed herein, and combining said GPAM with a fiber slurry, or applying said GPAM to a paper sheet. In some embodiments, said GPAM has a weight average molecular weight of from about 10,000 g/mole to 10,000,000 g/mole. In further embodiments, said aldehyde-functionalized polymer (such as GPAM) has a glyoxal to acrylamide (G/A ratio) of about 0.4 to about 1 to about 20 to about 1, or 0.4:1 to 20:1, or 0.4:1, or 0.8:1.
[0194] Another aspect of the invention pertains to a method for enhancing paper strength and press section dewatering of a paper sheet on a paper machine comprising adding to the paper sheet about 0.05 lb/ton to about 20 lb/ton, based on dry fiber, an aqueous composition prepared by a method comprising: [0195] (a) initiating a crosslinking reaction to generate GPAM by combining at least a polyacrylamide and glyoxal to obtain a reaction solution; [0196] (b) quenching the reaction by adjusting the pH of the reaction of step (a) to a value in a range from about 2 to about 6 (or about 4 to about 6), once a target viscosity of the GPAM is met; wherein the progress of GPAM formation is monitored by measuring the viscosity of the reaction solution via feedback loop from an online viscosity meter; and [0197] (c) combining said GPAM of step (b) with a fiber slurry or applying said GPAM to a paper sheet.
[0198] In certain embodiments, the present disclosure provides a method for generating an aldehyde-functionalized polymer (such as GPAM) composition for treating the strength and press section dewatering of a paper sheet. The composition comprises one or more aldehyde-functionalized polymers (such as GPAM) prepared according to the method. In some embodiments, said GPAM has a weight average molecular weight of from about 10,000 g/mole to 10,000,000 g/mole. In further embodiments, said aldehyde-functionalized polymer (such as GPAM) has a glyoxal to acrylamide (G/A ratio) of about 0.4 to about 1 to about 20 to about 1, or 0.4:1 to 20:1, or 0.4:1, or 0.8:1.
[0199] In another embodiment, the present disclosure provides a method for enhancing the strength and press section dewatering of a paper sheet on a paper machine. The method comprises adding to the paper sheet about 0.05 lb/ton to about 20 lb/ton, based on dry fiber, of a composition comprising GPAM comprising amino groups, amide groups, or a combination of amino and amide groups thereof, wherein (i) at least about 15 mole percent of the amino groups, amide groups, or both the amino or amide groups are functionalized with glyoxal, (ii) the amino groups, amide groups, or both the amino or amide groups are mono-reacted and di-reacted at a ratio of at least about 1.5 to 1, and (iii) the GPAM has a weight average molecular weight of from about 10,000 g/mole to about 10,000,000 g/mole.
[0200] The amount of GPAM added to the paper sheet is not limited. In certain embodiments, a composition comprising one or more aldehyde-functionalized polymers is added to the paper sheet in from about 0.05 lb/ton to about 20 lb/ton, based on dry fiber. Thus in certain embodiments, a composition comprising GPAM is added to the paper sheet in from about 0.05 lb/ton to about 20 lb/ton, from about 0.05 lb/ton to about 18 lb/ton, from about 0.05 lb/ton to about 15 lb/ton, from about 0.05 lb/ton to about 12 lb/ton, from about 0.05 lb/ton to about 10 lb/ton, from about 0.05 5 lb/ton to about 8 lb/ton, from about 0.05 lb/ton to about 6 lb/ton, from about 0.05 lb/ton to about 4 lb/ton, from about 0.05 lb/ton to about 3 lb/ton, from about 0.15 lb/ton to about 2 lb/ton, from about 1 lb/ton to about 20 lb/ton, from about 1 lb/ton to about 18 lb/ton, from about 1 lb/ton to about 15 lb/ton, from about 2 lb/ton to about 20 lb/ton, from about 2 lb/ton to about 18 lb/ton, from about 2 lb/ton to about 15 lb/ton, from about 5 lb/ton to about 15 lb/ton, from about 1 lb/ton to 10 about 10 lb/ton, from about 1 lb/ton to about 5 lb/ton, or from about 5 lb/ton to about 10 lb/ton. In certain embodiments, a composition comprising GPAM is added to the paper sheet in from about 0.05 lb/ton to about 3 lb/ton.
[0201] The GPAM of the invention may be added to the papermaking system in any form, such as a solution comprising unreacted aldehyde (glyoxal). The solution comprising GPAM may comprise unreacted aldehyde (glyoxal) in any suitable amount. In certain embodiments, the solution comprising GPAM of the invention comprises unreacted glyoxal in an amount from about 40% to about 95%, from about 40% to about 90%, from about 40% to about 85%, from about 40% to about 80%, from about 40% to about 75%, from about 40% to about 70%, from about 40% to about 65%, from about 40% to about 60%, from about 45% to about 95%, from about 50% to about 95%, from about 55% to about 95%, from about 60% to about 95%, from about 65% to about 95%, from about 70% to about 95%, from about 75% to about 95%, or from about 80% to about 95%. In certain embodiments, the solution comprising GPAM comprises unreacted glyoxal in an amount from about 60% to about 95%.
[0202] In certain embodiments, the present disclosure provides a paper sheet produced according to one of the aforementioned methods.
[0203] In certain embodiments, GPAM is added to a papermaking system as an aqueous solution. In certain embodiments, GPAM is added to a papermaking system as a solution in a co-solvent miscible with water. In certain embodiments, the GPAM is sprayed onto the paper sheet prior to press dewatering.
[0204] The composition and method of the present disclosure may be used in any papermaking process, including in a method of making paper products from pulp comprising forming an aqueous cellulosic papermaking furnish, draining the furnish to form a sheet and drying the sheet. The steps of forming the papermaking furnish, draining and drying may be carried out in any conventional manner generally known to those skilled in the art. Conventional microparticles, alum, cationic starch or a combination thereof may be utilized as adjuncts with the polymer treatment of the present disclosure, though it must be emphasized that no adjunct is required for effective dewatering activity.
[0205] The GPAM of the present disclosure may be added in traditional wet end locations used for conventional wet end additives. These include thin stock or thick stock. The actual wet end location is not considered to be critical. Because GPAM are believed to act as pressing aids, their addition to the wet end is not necessary, and the option of adding them just prior to the press section after the formation of the sheet can also be practiced. For example, the GPAM can be sprayed (e.g., using a shower bar) on the wet web prior to entering the press section, and this may be a preferred mode of addition to reduce dosages or the effects of interferences which might occur in the wet end. Other traditional wet end additives can be used in combination with the aldehyde functionalized polymers. These include retention aids, strength additives such as starches, sizing agents, and the like.
[0206] When using GPAM as described herein having net anionic charge, a method of fixing the polymer to the fiber may be needed. This fixing may be accomplished by using cationic materials in conjunction with the polymer. Such cationic materials may include coagulants, either inorganic (e.g. alum, polyaluminum chlorides, iron chloride or sulfate, and any other cationic hydrolyzing salt) or organic (e.g. p-DADMACs, EPI/DMAs, PEls, modified PEls or any other high charged density low to medium molecular weight polymers). Additionally, cationic materials added for other purposes like starch, wet strength, or retention additives may also serve to fix the anionic polymer. No additional additives are generally needed to fix cationic aldehyde-functionalized polymers to the filler.
[0207] The GPAM may be used for dewatering all grades of paper and paperboard. In certain embodiments, the GPAM are used to prepare recycle board grades using OCC (old corrugated containers), with or without mixed waste. In certain other embodiments, the GPAM is used to prepare virgin, recycled, mechanical, chemical, bleached, or unbleached paper.
[0208] In certain embodiments, a composition comprising GPAM further comprises a cationic starch.
EMBODIMENTS
[0209] A non-limiting list of embodiments is provided below: [0210] 1. A method of making GPAM, said method comprising: [0211] (a) combining at least a polyacrylamide and glyoxal to obtain a reaction solution; and [0212] (b) quenching the reaction by adjusting the pH of the reaction solution to a value in a range from about 2 to about 6 to obtain said GPAM; [0213] wherein progress of the reaction is monitored by measuring the viscosity of the reaction solution from an online viscosity meter. [0214] 2. The method of embodiment 1, wherein said GPAM has a weight average molecular weight of from about 10,000 g/mole to 10,000,000 g/mole. [0215] 3. The method of any of the preceding embodiments, wherein said GPAM has a glyoxal to acrylamide (G/A ratio) of about 0.05:1 to about 20:1, or 0.1:1 to about 20:1. [0216] 4. The method of embodiment 1, wherein the progress of said reaction is monitored by continuously measuring the viscosity of said reaction solution, optionally with feedback control. [0217] 5. The method of any of the preceding embodiments, wherein the online viscosity meter comprises: [0218] (a) a transducer assembly comprising: [0219] (i) at least one flow tube inserted into a pipe, said flow tube having a lumen conducting the reaction solution and said flow tube being clamped at an inlet end and an outlet end so as to be capable of vibrating; [0220] (ii) an electromechanical excitation arrangement; and [0221] (iii) a sensor arrangement; and [0222] (b) meter electronics. [0223] 6. The method of any of the preceding embodiments, wherein the reaction is quenched when the viscosity of the reaction solution compared to its initial viscosity has increased more than 100%. [0224] 7. The method of any of the preceding embodiments, wherein the pH of the reaction in step (a) is maintained in a range of from about 8 to about 9 by adding a caustic solution (wherein said caustic solution is optionally further diluted with water). [0225] 8. The method of any of the preceding embodiments, wherein in step (b) said quenching comprises adding an organic acid (such as citric acid). [0226] 9. The method of any of the preceding embodiments, wherein said GPAM has a glyoxal to acrylamide (G/A ratio) of in the range of about 0.4:1 to about 20:1. [0227] 10. The method of any of the preceding embodiments, wherein at least one of steps (a) to (b) is conducted at a paper production site. [0228] 11. The method of any of the preceding embodiments, wherein the GPAM is prepared onsite in a semi-batch or a full batch. [0229] 12. The method of any of the preceding embodiments, wherein said method is performed as a batch or semi-batch process. [0230] 13. The method of any of the preceding embodiments, wherein said polyacrylamide is a copolymer of acrylamide/DADMAC. [0231] 14. The method of embodiment 13, wherein said copolymer is about 1-30 mole % DADMAC and about 70-99 mole % acrylamide. [0232] 15. The method of embodiment 1, wherein said viscometer is an open flow tube viscometer. [0233] 16. The method of embodiment 1, wherein said viscosity meter comprises a measuring system having at least one measuring tube, which in measurement operation is filled with the reaction solution, or through which the reaction solution is flowing, and which has at least one tube section excitable to execute oscillations, an exciter system for exciting at least two wanted oscillation modes of different frequencies, at each of which at least one of the tube sections is excited to execute oscillations, especially resonant oscillations, [0234] a sensing system, which is embodied in such a manner that it determines for the wanted oscillation modes excited in measurement operation, in each case, a frequency and a damping, especially a frequency, an amplitude and a damping, of a resulting oscillation of at least one tube section excited to execute oscillations of one of the wanted oscillation modes, and an evaluation system, which is embodied in such a manner that it determines, based on calibration data stored in a memory for the individual wanted oscillation modes excited in measurement operation, in each case, based on an excitation determined frequency and damping, especially frequency, amplitude and damping, of the resulting oscillation a shear rate value and a viscosity measured value, wherein the viscosity measured value corresponds to the dynamic viscosity of the GPAM at a static shear rate corresponding to the shear rate value. [0235] 17. A method for enhancing paper strength and press section dewatering of a paper sheet on a paper machine comprising adding to the paper sheet about 0.05 lb/ton to about 20 lb/ton, based on dry fiber, of an aqueous composition prepared by a method according to any of the preceding embodiments. [0236] 18. A method of generating aldehyde-functionalized polymer, said method comprising: [0237] (a) combining at least a polymer comprising at least one amide group or amino group and an aldehyde to obtain a reaction solution; and [0238] (b) quenching the reaction by adjusting the pH of the reaction solution to a value in a range from about 2 to about 6 (or about 4 to about 6) to obtain said aldehyde-functionalized polymer; [0239] wherein progress of the reaction is monitored by measuring the viscosity of the reaction solution from an online viscosity meter. [0240] 19. The method of embodiment 18, wherein said aldehyde is chosen from formaldehyde, paraformaldehyde, and glutaraldehyde. [0241] 20. A method according to embodiment 18, wherein said method further comprises contacting said GPAM prepared according to any of the preceding embodiments with a fiber slurry, or with a paper sheet. [0242] 21. A paper sheet produced according to the method of embodiment 17 or embodiment 20. [0243] 22. A method for enhancing paper strength and press section dewatering of a paper sheet on a paper machine comprising adding to the paper sheet about 0.05 lb/ton to about 20 lb/ton, based on dry fiber, of an aqueous composition prepared by a method according to embodiment 18 or embodiment 19. [0244] 23. A method according to embodiment 18, wherein said method further comprises contacting said GPAM with a fiber slurry or with a paper sheet. [0245] 24. A paper sheet produced according to the method of embodiments 22 or 23. [0246] 25. The method of any of the preceding embodiments, wherein progress of making GPAM is monitored by measuring the viscosity of the reaction solution via feedback loop from an online viscosity meter. [0247] 26. The method of any of the preceding embodiments, wherein the reaction is quenched when the viscosity of the reaction solution is at least 3 cP. [0248] 27. The method of any of the preceding embodiments, wherein the reaction is quenched when the viscosity of the reaction solution is in a range of about 20 cP to about 1,000 cP. [0249] 28. A GPAM composition comprising GPAM prepared according to a method of any of the preceding embodiments, wherein said GPAM has a weight average molecular weight of from about 10,000 g/mole to 10,000,000 g/mole and wherein said GPAM has a glyoxal to acrylamide (G/A ratio) in the range of about 0.4:1 to about 20:1. [0250] 29. A method of making GPAM, said method comprising: [0251] (a) combining at least a polyacrylamide and glyoxal to obtain a reaction solution; and [0252] (b) quenching the reaction by adjusting the pH of the reaction solution to a value in a range from about 2 to about 6 (or about 4 to about 6) to obtain said GPAM; [0253] wherein the progress of the reaction is monitored by measuring the viscosity of the reaction solution via feedback loop from an online viscosity meter; [0254] wherein said polyacrylamide has a weight average molecular weight of about 7,000-50,000 Daltons; [0255] wherein said reaction is quenched when the reaction solution is a viscosity in the range of about 12 cp to about 40 cP. [0256] 30. A method of making GPAM, said method comprising: [0257] (a) combining at least a polyacrylamide and glyoxal to obtain a reaction solution; and [0258] (b) quenching the reaction by adjusting the pH of the reaction solution to a value in a range from about 2 to about 6 (or about 4 to about 6) to obtain said GPAM; [0259] wherein the progress of the reaction is monitored by measuring the viscosity of the reaction solution via feedback loop from an online viscosity meter; [0260] wherein said polyacrylamide has a weight average molecular weight of about 50,000-200,000 Daltons; [0261] wherein said reaction is quenched when the reaction solution is a viscosity in the range of about 20 cP to about 1,000 cP (where the measurement of viscosity is based on measurement at ambient temperature and where the reaction solution has a concentration of 8-10% concentration/solids). [0262] 31. A method of making GPAM, said method comprising: [0263] (a) combining at least a polyacrylamide and glyoxal to obtain a reaction solution; and [0264] (b) quenching the reaction by adjusting the pH of the reaction solution to a value in a range from about 2 to about 6 (or about 4 to about 6) to obtain said GPAM; [0265] wherein the progress of the reaction is monitored by measuring the viscosity of the reaction solution via feedback loop from an online viscosity meter; [0266] wherein said polyacrylamide has a weight average molecular weight of about 15,000 Daltons; [0267] wherein said reaction is quenched when the reaction solution is a viscosity in the range of about 10 cP to about 100 cP (where the measurement of viscosity is based on measurement at ambient temperature and where the reaction solution has a concentration of 6-15% concentration/solids). [0268] 32. The method of embodiment 1, wherein said polyacrylamide has a weight average molecular weight of 7,000-50,000 Daltons; and [0269] wherein said reaction is quenched at a viscosity in the range of about 10 cp to about 40 cP. [0270] 33. The method of embodiment 1, wherein said polyacrylamide has a weight average molecular weight of 50,000-200,000 Daltons; and [0271] wherein said reaction is quenched at a viscosity in the range of about 20 cP to about 1,000 cP. [0272] 34. The method of embodiment 1, wherein said polyacrylamide has a weight average molecular weight of 15,000—about 20,000 Daltons; wherein the reaction solution has an initial viscosity of about 2-4 cP; and [0273] wherein said reaction is quenched at a viscosity in the range of about 10-15 cP. [0274] 35. The method of embodiment 1, wherein said polyacrylamide has a weight average molecular weight of 30,000—about 50,000 Daltons; wherein the reaction solution has an initial viscosity of about 5-8 cP and [0275] wherein said reaction is quenched at a viscosity in the range of about 25 cp to about 40 cP (or 30 cp to about 40 cP). [0276] 36. The method of embodiment 1, wherein said reaction solution has an initial viscosity of about 2-10 cP. [0277] 37. The method of embodiments 1, 18, or 29-31, wherein the reaction is quenched when the viscosity of the reaction solution compared to its initial viscosity has increased more than 100%. [0278] 38. The method of embodiments 1, 18, or 29-31, wherein the reaction of step (a) is quenched when the viscosity of the reaction solution compared to its initial viscosity has increased 300-400%. [0279] 39. The method of embodiments 1, 18, or 29-31, wherein the reaction of step (a) is quenched when the viscosity of the reaction solution compared to its initial viscosity has increased 300-400%. [0280] 40. The method of embodiments 1, 18, or 29-31, wherein the reaction of step (a) is quenched when the viscosity of the reaction solution compared to its initial viscosity has increased by at least 50%. [0281] 41. The method of embodiments 1, 18, or 29-31, wherein the reaction of step (a) is quenched when the viscosity of the reaction solution compared to its initial viscosity has increased by at least 100%. [0282] 42. The method of embodiments 1, 18, or 29-31, wherein the reaction of step (a) is quenched when the viscosity of the reaction solution compared to its initial viscosity has increased about 300 to about 500%. [0283] 43. The method of embodiments 1, 18, or 29-31, wherein the reaction of step (a) is quenched when the viscosity of the reaction solution compared to its initial viscosity has increased about 300 to about 400%. [0284] 44. The method of embodiments 1, 18, or 29-31, wherein the reaction of step (a) is quenched when the viscosity of the reaction solution compared to its initial viscosity has increased about 400%. [0285] 45. The method of embodiments 1, 18, or 29-31, wherein the reaction of step (a) is quenched when the viscosity of the reaction solution compared to its initial viscosity has increased about 350%. [0286] 46. The method of embodiments 1, 18, or 29-31, wherein said polyacrylamide is a copolymer of acrylamide/DADMAC. [0287] 47. The method of embodiments 1, 18, or 29-31, wherein said copolymer comprises about 1-30 mole % DADMAC and 70-99 mole % acrylamide. [0288] 48. The method of embodiment 46, wherein said copolymer is 95/5 mole % acrylamide/DADMAC copolymer. [0289] 49. The method of embodiment 46, wherein said copolymer is 80/20 mole % acrylamide/DADMAC copolymer. [0290] 50. The method of embodiment 1, wherein said polyacrylamide has a weight average molecular weight of 50,000-200,000 Daltons; and [0291] wherein said reaction is quenched at a viscosity in the range of about 20 cP to about 1,000 cP. [0292] 51. The method of embodiment 1, wherein said step (a) comprises combining said polyacrylamide with water to obtain a mixture, and adding said glyoxal to the mixture to obtain said reaction solution. [0293] 52. The method of embodiment 1, wherein said step (a) comprises combining said glyoxal with water to obtain a mixture and adding said polyacrylamide to the mixture to obtain said reaction solution. [0294] 53. The method of embodiment 1, wherein step(a) comprises adjusting the temperature to between about 65-85 deg F. [0295] 54. The method of embodiment 1, wherein step(a) comprises adjusting the temperature to between about 60-80 deg F. [0296] 55. The method of embodiment 1, wherein step(a) comprises adjusting the temperature to between about 70 to about 75 deg F. [0297] 56. The method of embodiment 1, wherein step(a) comprises adjusting the temperature to about 75 deg F. [0298] 57. The method of embodiment 1, wherein step (a) followed by step (b) is repeated at least twice. [0299] 58. The method of embodiment 1, wherein said pH is monitored in real time. [0300] 59. The method of embodiment 1, wherein said pH is measured using at least one pH meter. [0301] 60. The method of embodiment 1, wherein said pH is measured using at least two pH meters. [0302] 61. A GPAM composition comprising GPAM prepared according to a method of any of the preceding embodiments, wherein said GPAM has a weight average molecular weight of from about 10,000 g/mole to 10,000,000 g/mole and wherein said GPAM has a glyoxal to acrylamide (G/A ratio) in the range of about 0.1:1 to about 20:1. [0303] 62. The method of any of the preceding embodiments, wherein the pH of the reaction solution is adjusted to a value in a range from about 4 to about 6.
EXAMPLES
[0304] The foregoing may be better understood by reference to the following examples, which are presented for purposes of illustration and are not intended to limit the scope of the invention.
Example 1
[0305] Preparation of 95/5 Mole % Acrylamide/DADMAC Copolymer To a 1500-mL reaction flask fitted with a mechanical stirrer, thermocouple, condenser, nitrogen purge tube, and addition port is added 116.4 g of deionized or soft water, 26.3 g of phosphoric acid, 63.8 g of a 62% aqueous solution of diallyldimethyl ammonium chloride (Nalco Company, Naperville, Ill.), 7.6 g of sodium formate, and 0.09 g of ethylenediaminetetraacetic acid, tetra sodium salt. The reaction mixture is stirred at 400 rpm and the pH adjusted to 4.7 to 4.9 using 17.3 g of aqueous 50% sodium hydroxide solution. The resulting mixture is heated to 100° C. and purged with nitrogen at 50 mL/min. Upon reaching 100° C., 17.6 g of a 25.0% aqueous solution of ammonium persulfate is added to the reaction mixture over a period of 135 minutes. Five minutes after starting the ammonium persulfate addition, 750.9 g of a 49.5% aqueous solution of acrylamide is added to the reaction mixture over a period of 120 minutes. The reaction is held at 100° C. for 180 minutes after ammonium persulfate addition. The reaction mixture is then cooled to ambient temperature and the pH is adjusted to 5.2 to 5.8 using 50% aqueous sodium hydroxide solution or concentrated sulfuric acid. The product is a viscous, clear to amber solution. The product has a molecular weight of about 20,000 g/mole.
Example 2
Preparation of GPAM Onsite
[0306] A set of 35 GPAM samples were produced using an on-site procedure (see e.g.,
TABLE-US-00002 TABLE 1 NMR results for the commercial GPAM BP612 and a sample produced using the on-site manufacturing method (GPAM-1). Unreacted Mono Di Reacted Unreacted Mono Di Sample Glyoxal % Glyoxal % Glyoxal % Amide % Amide % Amide % BFV, cP DADMAC:ACAM BP612 79 18 3 81 14 5 11.3 5:95 GPAM-1 74 22 5 74 18 8 11.1 5:95
[0307] A paper strength performance test was conducted using samples of a GPAMV (GPAMV-2) produced using the method according to the present disclosure. Three samples were tested in a hand sheet study; using three conditions. One sample was used within one hour of synthesis, one was used after aging for three hours at room temperature, and another was used after aging for three hours at 35° C. The performance of these samples was benchmarked against the commercial GPAM BP612. The hand sheets used in this study were prepared according to TAPPI Method T 205 and were tested for tensile strength (TAPPI Method T 494), burst strength (TAPPI Method T 403), short-span compression strength (SCT, TAPPI Method T 826), and ring crush strength (RCT, TAPPI Method T 822). The results were as summarized in Table 2 and
TABLE-US-00003 TABLE 2 Results of a hand sheet study conducted using three samples produced using the on-site manufacturing process and commercial BP612 GPAM material. Wet End Dose Percent Change from Blank Polymer (lbs/ton Tensile Burst Sample active) Aging Strength Strength SCT RCT Avg BP 612 3.0 N/A 6.79% 7.64% 8.21% 2.07% 6.18% BP 612 6.0 N/A 12.47% 14.66% 10.61% 3.98% 10.43% GPAM-2, 3.0 <1 h 7.67% 16.49% 8.33% 4.94% 9.36% run 1 GPAM-2, 6.0 <1 h 13.09% 23.44% 11.14% 7.30% 13.74% run 1 GPAM-2, 3.0 <1 h 5.21% 14.56% 8.47% 3.58% 7.95% run 2 GPAM-2, 6.0 .sub. 3 h 13.52% 18.10% 13.58% 6.39% 12.90% run 2 GPAM-2, 3.0 <1 h 6.12% 9.02% 8.28% 1.43% 6.21% run 3 GPAM-2, 6.0 3 h @ 11.82% 19.41% 13.96% 6.94% 13.03% run 3 35° C.
[0308] Average strength improvement of GPAM-2 samples produced using the on-site manufacturing process and the commercial BP612 GPAM material (see
[0309] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
[0310] Embodiments of the present disclosure are described herein, including the best mode known to the inventors for carrying out the invention. Variations of these embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
[0311] While this invention may be embodied in many different forms, there are described in detail herein specific preferred embodiments of the invention. The present disclosure is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated. All patents, patent applications, scientific papers, and any other referenced materials mentioned herein are incorporated by reference in their entirety. Furthermore, the invention encompasses any possible combination of some or all of the various embodiments mentioned herein, described herein and/or incorporated herein. In addition the invention encompasses any possible combination that also specifically excludes any one or some of the various embodiments mentioned herein, described herein and/or incorporated herein.
[0312] Any information in any material (e.g., a United States patent, United States patent application, book, article, etc.) that has been incorporated by reference herein, is only incorporated by reference to the extent that no conflict exists between such information and the other statements and drawings set forth herein. In the event of such conflict, including a conflict that would render invalid any claim herein, then any such conflicting information in such incorporated by reference material is specifically not incorporated by reference herein.
[0313] The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims.
[0314] All ranges and parameters disclosed herein are understood to encompass any and all subranges subsumed therein, and every number between the endpoints. For example, a stated range of “1 to 10” should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more, (e.g. 1 to 6.1), and ending with a maximum value of 10 or less, (e.g. 2.3 to 9.4, 3 to 8, 4 to 7), and finally to each number 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 contained within the range. All percentages and proportions herein are by weight unless otherwise specified. G/A (glyoxal to amide) ratios disclosed herein are based on mole ratios. Further, the NMR results disclosed herein are based on mole ratios.
[0315] This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.