GPAM Compositions and Methods

Abstract

The present invention generally relates to glyoxalated polyacrylamide (GPAM) compositions, methods for their preparation and use, particularly in the paper industry. In addition, the present invention generally relates to cationic GPAM compositions, methods for their preparation and use in papermaking applications and products such as paper-based products, wherein the cationic GPAM compositions can provide increased wet strength and / or dry strength to the paper-based products, and wherein such cationic GPAM compositions optionally require a reduced volume of aqueous carrier for storage or transportation compared to the volume of aqueous carrier required for conventional GPAM used in papermaking.

Description

Technical Field

[0001] The present disclosure generally relates to glyoxalated polyacrylamide (GPAM) compositions, articles comprising such compositions, and methods of using the same, particularly GPAM compositions for use in the paper industry, and more particularly cationic GPAM compositions and their use in papermaking applications and products such as paper-based products. The present disclosure also generally relates to methods of preparing the cationic GPAM compositions. Background Art

[0002] Glyoxalated polyacrylamide (GPAM) compositions are widely used in the paper industry, typically to increase the wet strength and dry strength of paper. For example, glyoxalated polyacrylamide can increase the initial wet strength of many household paper towels, a useful property since household paper towels are often in contact with water during use. Application of glyoxalated polyacrylamide to paper products can also increase the compressive strength and dimensional stability of many board grade paper products.

[0003] GPAM is typically prepared by the reaction between glyoxal and a polyacrylamide base polymer such as a cationic polyacrylamide backbone. In some cases, the reaction between glyoxal and cationic polyacrylamide occurs in a weakly basic aqueous solution and is stable under acidic conditions. In fact, the polyacrylamide component of GPAM compositions typically contains a relatively small amount of cationic monomers, generally less than about 5 mole % thereof, thereby limiting the contribution of cationic charge to the GPAM composition.

[0004] In addition, GPAM prepared by conventional methods generally cannot be dried into solid particle form without inducing significant and rapid crosslinking of the GPAM, which limits the utility of the resulting GPAM composition. Thus, GPAM compositions are typically stored and transported in a bulk aqueous fluid carrier. The volume of GPAM composition transported in this manner can be quite large, which generally requires large volume containers or tankers for transportation. Transporting such large amounts of product significantly increases the cost of transporting and using GPAM compositions.

[0005] Due to the nature of current GPAM compositions and logistical considerations regarding their transportation, there remains a need for GPAM compositions that include properties that facilitate lower transportation costs and / or lower transportation volumes of the GPAM composition while still maintaining the desired properties of the GPAM composition. Summary of the Invention

[0006] The present disclosure generally relates to a cationic glyoxalated polyacrylamide (“GPAM”) composition suitable for use as a dry and / or wet strength agent, wherein the cationic GPAM composition comprises: a. a first base polymer having a weight average molecular weight of less than 30,000 Da; and b. a second base polymer having a weight average molecular weight of at least 30,000 Da; wherein the weight ratio of the first base polymer to the second base polymer is from about 10:90 to about 90:10, optionally from about 20:80 to about 80:20, further optionally from about 30:70 to about 70:30; wherein the first base polymer and the second base polymer are each glyoxalated; and wherein optionally, compared to the volume of the aqueous carrier required for conventional GPAM used in papermaking, the cationic GPAM composition requires a reduced volume of aqueous carrier for storage or transportation.

[0007] In some embodiments, the weight-average molecular weight of the first base polymer can be at most 25 kDa or less, 20 kDa or less, 15 kDa or less, 10 kDa or less, or 8 kDa or less. In some embodiments, the weight-average molecular weight of the second base polymer can be at least 30 kDa or more, 40 kDa or more, 50 kDa or more, 75 kDa or more, 100 kDa or more, 125 kDa or more, 150 kDa or more, 175 kDa or more, 200 kDa or more, 225 kDa or more, 250 kDa or more, 275 kDa or more, 300 kDa or more, 325 kDa or more, 350 kDa or more, 375 kDa or more, 400 kDa or more, or 500 kDa or more. In some embodiments, the glyoxalation percentage of the cationic GPAM composition can be from about 2% to about 90%, optionally from about 3% to about 80%, further optionally from about 4% to about 70%, and further optionally from about 5% to about 60%. In some embodiments, the glyoxalation percentage of the first base polymer can be from about 2% to about 90%, optionally from about 3% to about 80%, further optionally from about 4% to about 70%, and further optionally from about 5% to about 60%. In some embodiments, the glyoxalation percentage of the second base polymer can be from about 2% to about 90%, optionally from about 3% to about 80%, further optionally from about 4% to about 70%, and further optionally from about 5% to about 60%. In some embodiments, the GPAM content of the cationic GPAM composition can be from about 2% to about 20%, optionally from about 3% to about 10%, further optionally from about 4% to about 8%, and further optionally from about 5% to about 7%. In some embodiments, the GPAM content of the first base polymer can be from about 2% to about 20%, optionally from about 3% to about 10%, further optionally from about 4% to about 8%, and further optionally from about 5% to about 7%. In some embodiments, the GPAM content of the second base polymer can be from about 2% to about 20%, optionally from about 3% to about 10%, further optionally from about 4% to about 8%, and further optionally from about 5% to about 7%. In some embodiments, the first base polymer can contain at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 50 wt% or at least 60 wt% of cationic charge, where optionally the first base polymer can be amphoteric.In some embodiments, the second base polymer may comprise at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 50 wt% or at least 60 wt% of cationic charge, wherein optionally the second base polymer may be amphoteric. In some embodiments, the first base polymer may comprise at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 50 wt% or at least 60 wt% of cationic monomer percentage, wherein optionally the first base polymer may be amphoteric. In some embodiments, the second base polymer may comprise at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 50 wt% or at least 60 wt% of cationic monomer percentage, wherein optionally the second base polymer may be amphoteric. In some embodiments, the cationic GPAM composition may comprise a solids weight percentage of about 1.0% or greater, 2.0% or greater, 3.0% or greater, 4.0% or greater, 5.0% or greater, 5.5% or greater, 6.0% or greater, 6.5% or greater, 7.0% or greater, 7.5% or greater, 8.0% or greater, 8.5% or greater, 9.0% or greater, 9.5% or greater, 10.0% or greater, 10.5% or greater, 11.0% or greater, or 11.5% or greater. In some embodiments, the cationic GPAM composition may comprise a solids weight percentage of about 1.0% to about 20.0%, optionally about 3.0% to about 15.0%. In some embodiments, the cationic GPAM composition may comprise a glyoxal to total base polymer weight ratio of at least about 1:99, at least about 2.5:97.5, at least about 5:95, at least about 7.5:92.5, at least about 10:90, at least about 12.5:87.5, at least about 15:85, at least about 17.5:82.5, at least about 20:80, at least about 22.5:77.5, at least about 25:75, at least about 27.5:72.5, at least about 29:71 or at least about 30:70. In some embodiments, the first base polymer may comprise an acrylamide-based polymer. In some embodiments, the second base polymer may comprise an acrylamide-based polymer. In some embodiments, the first base polymer may comprise one or more cationic monomers. In some embodiments, the second base polymer may comprise one or more cationic monomers.In some embodiments, the first base polymer may comprise a cationic monomer:acrylamide weight ratio of from about 15:85 to about 60:40, optionally from about 20:80 to about 55:45, and further optionally from about 25:75 to about 50:50. In some embodiments, the second base polymer may comprise a cationic monomer:acrylamide weight ratio of from about 15:85 to about 60:40, optionally from about 20:80 to about 55:45, and further optionally from about 25:75 to about 50:50. In some embodiments, the first base polymer may be amphoteric and may comprise more cationic monomers than anionic monomers. In some embodiments, the second base polymer may be amphoteric and may comprise more cationic monomers than anionic monomers. In some embodiments, the first base polymer may comprise a copolymer of acrylamide or methacrylamide and one or more cationic monomers. In some embodiments, the second base polymer may comprise a copolymer of acrylamide or methacrylamide and one or more cationic monomers. In some embodiments, the viscosity of the cationic GPAM composition may be about 10 cPs or greater, about 15 cPs or greater, about 20 cPs or greater, about 25 cPs or greater, about 30 cPs or greater, or about 35 cPs or greater, such as measured using spindle No. 1 with an LV Brookfield viscometer at 25 °C and 600 rpm. In some embodiments, the aqueous carrier may comprise water.

[0008] In some embodiments, the one or more cationic monomers may each independently be selected from the group consisting of acryloyloxyethyl trimethylammonium chloride (“AETAC”), methacryloyloxyethyl trimethylammonium chloride, methacrylamidopropyl trimethylammonium chloride (“MAPTAC”), acrylamidopropyl trimethylammonium chloride, methacryloyloxyethyl dimethyl ammonium sulfate, dimethylaminoethyl acrylate, dimethylaminopropyl methacrylamide, methacryloyloxyethyl trimethylammonium chloride methacrylic acid dimethylaminoethyl ester sulfate, diallyldimethylammonium chloride (“DADMAC”); dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates and their quaternary or acid salts, including but not limited to dimethylaminoethyl acrylate methyl chloride quaternary salt (“DMAEA.MCQ”), dimethylaminoethyl acrylate methyl sulfate quaternary salt (“DMAEM.MCQ”), dimethylaminoethyl acrylate benzyl chloride quaternary salt (“DMAEA.BCQ”), dimethylaminoethyl acrylate sulfate, dimethylaminoethyl acrylate hydrochloride, diethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfate, dimethylaminoethyl methacrylate hydrochloride, dimethylaminoethyl methacryloyl hydrochloride; dialkylaminoalkyl acrylamides or dialkylaminoalkyl methacrylamides and their quaternary ammonium or acid salts, such as acrylamidopropyl trimethylammonium chloride, dimethylaminopropyl acrylamide methyl sulfate quaternary salt, dimethylaminopropyl acrylamide sulfate, dimethylaminopropyl acrylamide hydrochloride, methacrylamidopropyl trimethylammonium chloride, dimethylaminopropyl methacrylamide methyl sulfate quaternary salt, dimethylaminopropyl methacrylamide sulfate, dimethylaminopropyl methacrylamide hydrochloride, diethylaminoethyl acrylate, diethylaminoethyl methacrylate; and diallyldialkylammonium halides, such as diallyldiethylammonium chloride and diallyldimethylammonium chloride. In some embodiments, the one or more cationic monomers may include DADMAC. In some embodiments, the one or more cationic monomers may include acryloyloxyethyl trimethylammonium chloride (“Q9”). In some embodiments, the one or more cationic monomers may each include DADMAC and / or acryloyloxyethyl trimethylammonium chloride (“Q9”).In some embodiments, the one or more cationic monomers may each independently be selected from the group consisting of methacryloyloxyethyl trimethylammonium chloride, acryloyloxyethyl trimethylammonium chloride (also known as Q9), 3-(methacrylamido)propyl trimethylammonium chloride, 3-(acrylamido)propyl trimethylammonium chloride, diallyldimethylammonium chloride (DADMAC), dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, and dimethylaminopropyl acrylamide, dimethylaminopropyl methacrylamide.

[0009] In some embodiments, the acrylamide-based polymer may comprise one or more monomers containing a primary amide. In some embodiments, the acrylamide-based polymer may comprise one or more monomers selected from the group consisting of acrylamide, methacrylamide, ethylacrylamide, crotonamide, N-methylacrylamide, N-butylacrylamide, N-ethylmethylacrylamide, and any combination thereof. In some embodiments, the acrylamide-based polymer may comprise one or more acrylamide monomers.

[0010] In some exemplary embodiments, the cationic GPAM in the GPAM composition is selected from the following:

[0011] a. The first base polymer and the second base polymer comprise a copolymer of acrylamide or methacrylamide and one or more cationic monomers;

[0012] b. The first base polymer and / or the second base polymer comprise a copolymer of (a) acrylamide and / or methacrylamide and acryloyloxyethyl trimethylammonium chloride and / or (b) diallyldimethylammonium chloride (DADMAC) monomers;

[0013] c. The first base polymer or the second base polymer comprises a copolymer of acrylamide and diallyldimethylammonium chloride (DADMAC) monomers;

[0014] d. The first base polymer and the second base polymer comprise a copolymer of acrylamide and diallyldimethylammonium chloride (DADMAC) monomers;

[0015] e. The first base polymer and the second base polymer comprise a copolymer of acrylamide and diallyldimethylammonium chloride (DADMAC) monomers, and the glyoxal:base polymer ratio for the glyoxalation reaction ranges from about 10:90 to 90:10, 20:80 to 80:20, 30:70 to 70:30, 40:60 to 60:40, or is about 29:71;

[0016] f. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC); the molecular weight of the first base polymer does not exceed 25 kDa, 20 kDa, 15 kDa, 8 kDa or 5 kDa, and the molecular weight of the second base polymer is at least 50 kDa, 100 kDa, 150 kDa, 200 kDa, 250 kDa or 246 kDa;

[0017] g. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; the molecular weight of the first base polymer does not exceed 25 kDa, 20 kDa, 15 kDa, 8 kDa or 5 kDa, and the molecular weight of the second base polymer is at least 50 kDa, 100 kDa, 150 kDa, 200 kDa, 250 kDa or about 246 kDa; and the glyoxal:base polymer ratio of the glyoxalation reaction for glyoxalating the first base polymer and / or the second base polymer ranges from about 10:90 to 90:10, 20:80 to 80:20, 30:70 to 70:30, 40:60 to 60:40, or is about 29:71;

[0018] h. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC); the molecular weight of the first base polymer does not exceed 25 kDa, 20 kDa, 15 kDa, 8 kDa or 5 kDa, and the molecular weight of the second base polymer is at least 50 kDa, 100 kDa, 150 kDa, 200 kDa, 250 kDa or about 246 kDa; the glyoxal:base polymer ratio of the glyoxalation reaction for the first base polymer and / or the second base polymer ranges from about 10:90 to 90:10, 20:80 to 80:20, 30:70 to 70:30, 40:60 to 60:40, or is about 29:71; and the weight ratio of the first base polymer to the second base polymer ranges from about 10:90 to about 90:10, optionally from about 20:80 to about 80:20, further optionally from about 30:70 to about 70:30, still further optionally from about 40:60 to about 60:40; or

[0019] i. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC); the molecular weight of the first base polymer does not exceed 25 kDa, 20 kDa, 15 kDa, 8 kDa or 5 kDa, and the molecular weight of the second base polymer is at least 50 kDa, 100 kDa, 150 kDa, 200 kDa, 250 kDa or about 246 kDa; the glyoxal:base polymer ratio for the glyoxalation reaction of the first base polymer and / or the second base polymer ranges from about 10:90 to 90:10, 20:80 to 80:20, 30:70 to 70:30, 40:60 to 60:40, or is about 29:71; and the weight ratio of the first base polymer to the second base polymer ranges from about 10:90 to about 90:10, optionally from about 20:80 to about 80:20, further optionally from about 30:70 to about 70:30, still further optionally from about 40:60 to about 60:40, and the GPAM content ranges from about 5% to about 7%, or about 6%-7.5%, or about 6% to 7%.

[0020] In addition, the present disclosure generally relates to paper products comprising one or more cationic GPAM compositions as discussed herein. In some embodiments, the paper product may include at least one paper layer or web containing the cationic GPAM composition. In some embodiments, the paper product may comprise the cationic GPAM composition on at least one surface of the paper product. In some embodiments, the paper product may include one or more of paper, cardboard, tissue paper, and wallboard. In some embodiments, the paper product may include one or more of kraft paper, sulfite paper, semi-chemical paper, etc., including paper produced using bleached pulp, unbleached pulp, or a combination thereof. In some embodiments, the paper product may include fiber-based products. In some embodiments, the paper product may include hand-sheets, board-based products, beverage carriers, towels, milk and juice cartons, food trays, paper bags, liners for corrugated boxes, packaging board grades, and tissue and towel grade paper materials, paper towels, diapers, sanitary napkins, training pants, pantiliners, incontinence briefs, tampons, urine pads, trash can liners, coffee filter bags, air filtration materials, drying pads, floor cleaning pads, absorbent facial tissues, absorbent toilet papers, napkins, wrapping papers, and / or other cardboard products such as carton and sack papers. In some embodiments, the paper product may include a cellulose cardboard web optionally comprising predominantly cellulose fibers. In some embodiments, the paper product may contain from about 0.02% to about 10% of the cationic GPAM composition, optionally in the range of about 0.05% to 5% by weight of the dry paper weight. In some embodiments, the paper product may include improved paper strength compared to a paper product that does not contain the cationic GPAM composition, as determined, for example, by the STFI test. For example, in some embodiments, compared to a blank sample for the STFI test for paper products, the paper product may include an STFI value improvement of 6% or greater, 7% or greater, 8% or greater, 9% or greater, 10% or greater, 12.5% or greater, 15.0% or greater, 17.5% or greater, 20.0% or greater, 22.5% or greater, 25.0% or greater at a test of 4.5 pounds / ton, 5.0 pounds / ton, 9.0 pounds / ton, or 10 pounds / ton. In some embodiments, the paper product may include improved paper strength compared to a paper product that does not contain the cationic GPAM composition, as determined, for example, by the burst strength test.For example, in some embodiments, the paper product may include a burst strength value improvement of 6% or greater, 7% or greater, 8% or greater, 9% or greater, 10% or greater, 12.5% or greater, 15.0% or greater, 17.5% or greater, 20.0% or greater, 22.5% or greater, 25.0% or greater, 27.5% or greater, 30.0% or greater, 32.5% or greater, 35.0% or greater, 37.5% or greater, or 40% or greater when tested at 4.5 pounds per ton, 5.0 pounds per ton, 9.0 pounds per ton, or 10 pounds per ton compared to a blank sample used for burst strength testing.

[0021] In some exemplary embodiments, a paper product comprising one or more cationic GPAM compositions comprises cationic GPAM, wherein:

[0022] a. The first base polymer and the second base polymer comprise a copolymer of acrylamide or methacrylamide monomers and one or more cationic monomers;

[0023] b. The first base polymer and / or the second base polymer comprise a copolymer of (a) acrylamide and / or methacrylamide and acryloyloxyethyl trimethyl ammonium chloride and / or (b) dimethyldiallylammonium chloride (DADMAC) monomers;

[0024] c. The first base polymer or the second base polymer comprises a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers;

[0025] d. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers;

[0026] e. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC), and the glyoxal:base polymer ratio for the glyoxalation reaction ranges from about 10:90 to 90:10, 20:80 to 80:20, 30:70 to 70:30, 40:60 to 60:40, or is about 29:71 monomers;

[0027] f. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC); the molecular weight of the first base polymer does not exceed 25 kDa, 20 kDa, 15 kDa, 8 kDa, or 5 kDa, and the molecular weight of the second base polymer is at least 50 kDa, 100 kDa, 150 kDa, 200 kDa, or 250 kDa or 246 kDa;

[0028] g. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; the molecular weight of the first base polymer does not exceed 25 kDa, 20 kDa, 15 kDa, 8 kDa or 5 kDa, and the molecular weight of the second base polymer is at least 50 kDa, 100 kDa, 150 kDa, 200 kDa, 250 kDa or about 246 kDa; and the glyoxal:base polymer ratio of the glyoxalation reaction for glyoxalating the first base polymer and / or the second base polymer ranges from about 10:90 to 90:10, 20:80 to 80:20, 30:70 to 70:30, 40:60 to 60:40, or is about 29:71;

[0029] h. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC); the molecular weight of the first base polymer does not exceed 25 kDa, 20 kDa, 15 kDa, 8 kDa or 5 kDa, and the molecular weight of the second base polymer is at least 50 kDa, 100 kDa, 150 kDa, 200 kDa, 250 kDa or about 246 kDa; the glyoxal:base polymer ratio of the glyoxalation reaction for the first base polymer and / or the second base polymer ranges from about 10:90 to 90:10, 20:80 to 80:20, 30:70 to 70:30, 40:60 to 60:40, or is about 29:71; and the weight ratio of the first base polymer to the second base polymer ranges from about 10:90 to about 90:10, optionally from about 20:80 to about 80:20, further optionally from about 30:70 to about 70:30, still further optionally from about 40:60 to about 60:40; or

[0030] i. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; the molecular weight of the first base polymer does not exceed 25 kDa, 20 kDa, 15 kDa, 8 kDa, or 5 kDa, and the molecular weight of the second base polymer is at least 50 kDa, 100 kDa, 150 kDa, 200 kDa, 250 kDa, or about 246 kDa; the glyoxal:base polymer ratio for the glyoxalation reaction of the first base polymer and / or the second base polymer ranges from about 10:90 to 90:10, 20:80 to 80:20, 30:70 to 70:30, 40:60 to 60:40, or is about 29:71; and the weight ratio of the first base polymer to the second base polymer ranges from about 10:90 to about 90:10, optionally from about 20:80 to about 80:20, further optionally from about 30:70 to about 70:30, still further optionally from about 40:60 to about 60:40, and the GPAM content ranges from about 5% to about 7%, or about 6% - 7.5%, or about 6% to 7%.

[0031] In addition, the present disclosure generally relates to a papermaking method, wherein the method comprises adding one or more cationic GPAM compositions as discussed herein during the papermaking method in an amount effective to increase the wet strength and / or dry strength of the paper product produced by the method. In some embodiments, the one or more cationic GPAM compositions can be added to a composition comprising fibers and / or pulp used in the method prior to forming the paper product. In some embodiments, the one or more cationic GPAM compositions can be added to one or more surfaces of the paper product after forming the paper product.

[0032] In addition, the present disclosure generally relates to a method of making hand sheets, the method comprising: a. providing a pulp slurry; b. diluting the pulp slurry; c. adding one or more salts to a desired conductivity level; d. adjusting the pH to a desired value; e. adding one or more cationic GPAM compositions as discussed herein; f. adding the treated pulp to a dynamic sheet former; g. pressing the sheet produced in f.; h. drying the sheet; and i. finishing the sheet.

[0033] Additionally, the present disclosure generally relates to a method of making one or more paper products, wherein the method comprises: a. providing a composition comprising primarily cellulose fibers; b. adding a predetermined amount of one or more cationic GPAM compositions as discussed herein; and c. forming the desired paper product.

[0034] In addition, the present disclosure generally relates to a method of manufacturing one or more paper products, optionally one or more absorbent paper products, wherein the method comprises: a. providing a composition comprising any one of softwood fibers, hardwood fibers, recycled fibers, refined fibers or a mixture of any of the foregoing, in an amount sufficient to form a total furnish of from about 1% to 100% hardwood fibers, softwood fibers, recycled fibers, refined fibers or a mixture of any of the foregoing; (b) adding a predetermined amount of one or more cationic GPAMs as discussed herein; and (c) forming a paper product by drying via one or more drying devices to a desired moisture content level.

[0035] In addition, the present disclosure generally relates to a method for strengthening paper, the method comprising contacting pulp fibers with a strengthening resin comprising at least a cationic GPAM composition as discussed herein, and at least partially curing the cationic GPAM in the mixture of pulp fibers and cationic GPAM to produce a strength-enhanced paper product.

[0036] In some embodiments, the cationic GPAM composition can be added to the cellulose fiber suspension at the wet end of a papermaking facility. In some embodiments, the cationic GPAM composition can be added in an amount ranging from about 0.02 dry weight % to about 10 dry weight % of the cellulose fibers, optionally in the range of about 0.05 weight % to 5 weight % of the dry paper weight. In some embodiments, the cationic GPAM composition can be added before, during, and / or after the formation of the paper. In some embodiments, after the formation of the paper product, the cationic GPAM composition can be added to one or more surfaces of the paper product. In some embodiments, the cationic GPAM composition can provide paper strength enhancement to the paper product, e.g., as determined by the STFI test. For example, in some embodiments, compared to a blank sample for the STFI test for the paper product, the paper product can include an STFI value improvement of 6% or greater, 7% or greater, 8% or greater, 9% or greater, 10% or greater, 12.5% or greater, 15.0% or greater, 17.5% or greater, 20.0% or greater, 22.5% or greater, 25.0% or greater when tested at 4.5 lbs / ton, 5.0 lbs / ton, 9.0 lbs / ton, or 10 lbs / ton. In some embodiments, the cationic GPAM composition can provide paper strength enhancement to the paper product, e.g., as determined by the burst strength test. For example, in some embodiments, compared to a blank sample for the burst strength test, the paper product can include a burst strength value improvement of 6% or greater, 7% or greater, 8% or greater, 9% or greater, 10% or greater, 12.5% or greater, 15.0% or greater, 17.5% or greater, 20.0% or greater, 22.5% or greater, 25.0% or greater, 27.5% or greater, 30.0% or greater, 32.5% or greater, 35.0% or greater, 37.5% or greater, or 40% or greater when tested at 4.5 lbs / ton, 5.0 lbs / ton, 9.0 lbs / ton, or 10 lbs / ton. In some embodiments, the paper product can include one or more of hand sheets, board-based products, beverage carriers, towels, milk and juice cartons, food trays, paper bags, liners for corrugated boxes, packaging board grades, and thin paper and towel grade paper materials, paper towels, diapers, sanitary napkins, training pants, pantiliners, incontinence briefs, tampons, urine pads, bin liners, coffee filter bags, air filtration materials, drying pads, floor cleaning pads, absorbent facial tissues, absorbent toilet tissues, napkins, wrapping papers, and / or other cardboard products such as carton and bag papers. In some embodiments, the paper product can include a cellulose cardboard paper web that optionally mainly comprises cellulose fibers. In some embodiments, the cationic GPAM composition can reduce the drainage time of the treated sample compared to the drainage time without using the cationic GPAM composition.For example, in some embodiments, compared to the water filtration without using the cationic GPAM composition, the cationic GPAM composition can achieve effective water filtration, such as the water filtration of OCC pulp, for example, showing an improvement in the water filtration time of 25.0% or more, 30.0% or more, 35.0% or more, 40.0% or more, 45.0% or more, 50.0% or more, 55.0% or more (for example, the time to collect a given amount of filtrate from the OCC pulp). In some embodiments, compared to the water filtration rate without using the cationic GPAM composition, the cationic GPAM composition can increase the water filtration rate of the treated sample, resulting in an increase in the paper production rate. In some embodiments, the cationic GPAM composition can improve the energy savings in drying the papermaking product. Further, compared to the total amount of solids present in a sample without using the cationic GPAM composition, the cationic GPAM composition can achieve a reduction in the total amount of solids present in the treated sample, for example, a reduction in the total solids present in the filtrate collected from the OCC pulp treated with the cationic GPAM composition, for example, a reduction in the solids content of the white water from the trays or the silos after paper forming, such as an improvement of 15% or more, 17.5% or more, 20.0% or more, 22.5% or more, 25.0% or more, 27.5% or more, 30.0% or more, or 32.5% or more (reduction in solids content). In some embodiments, the cationic GPAM composition can improve the energy savings in drying.

[0037] In addition, the present disclosure generally relates to a method for preparing the cationic GPAM compositions discussed herein, particularly cationic GPAM compositions comprising: a. a first base polymer having a weight average molecular weight of less than 30,000 Da; and b. a second base polymer having a weight average molecular weight of at least 30,000 Da; wherein the weight ratio of the first base polymer to the second base polymer is from about 10:90 to about 90:10, optionally from about 20:80 to about 80:20, further optionally from about 30:70 to about 70:30; wherein the first base polymer and the second base polymer are each glyoxalated; and wherein optionally, the cationic GPAM composition requires a reduced volume of aqueous carrier for storage or transportation compared to the volume of aqueous carrier required for conventional GPAM used in papermaking. In some embodiments, the method may comprise: a. glyoxalating the first base polymer in a first glyoxalation reaction comprising glyoxal to produce a first glyoxalated base polymer; b. glyoxalating the second base polymer in a second glyoxalation reaction comprising glyoxal to produce a second glyoxalated base polymer, wherein optionally, the first base polymer and / or the second base polymer comprises or consists of acrylamide or methacrylamide and a charged monomer such as DADMAC or acryloyloxyethyltrimethylammonium chloride; and c. combining the first glyoxalated base polymer and the second glyoxalated base polymer to produce the cationic GPAM composition; wherein steps (a) and (b) may be carried out in any order or simultaneously. In some embodiments, the method may comprise: a. combining the first base polymer and the second base polymer; and b. glyoxalating the combination of the first base polymer and the second base polymer in a glyoxalation reaction comprising glyoxal to produce the cationic GPAM composition. In some embodiments, the method may comprise: a. glyoxalating the first base polymer in a glyoxalation reaction comprising glyoxal to produce a first glyoxalated base polymer; and b. adding the second base polymer and optionally additional glyoxal to the glyoxalation reaction to produce the cationic GPAM composition. In some embodiments, the method may comprise: a. glyoxalating the second base polymer in a glyoxalation reaction comprising glyoxal to produce a second glyoxalated base polymer; and b. adding the first base polymer and optionally additional glyoxal to the glyoxalation reaction to produce the cationic GPAM composition. In some embodiments, the method may comprise: a. glyoxalating the first base polymer in a first glyoxalation reaction comprising glyoxal to produce a first glyoxalated base polymer; and b. glyoxalating the second base polymer and the first glyoxalated base polymer in a second glyoxalation reaction comprising glyoxal to produce the cationic GPAM composition.In some embodiments, the method may include a. glyoxalating the second base polymer in a second glyoxalation reaction comprising glyoxal to produce a second glyoxalated base polymer; and b. glyoxalating the first base polymer and the second glyoxalated base polymer in a first glyoxalation reaction comprising glyoxal to produce the cationic GPAM composition.

[0038] In addition, the present disclosure provides a cationic GPAM composition prepared by any of the foregoing methods.

[0039] Furthermore, the present disclosure provides a composition comprising one or more cationic GPAM compositions prepared by one or more of the foregoing methods. Detailed Description

[0040] Definitions

[0041] As used herein, unless the context clearly dictates otherwise, the singular forms "a / an" and "the" include plural referents. All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise specifically stated.

[0042] As used herein, unless otherwise indicated, when we refer to "%" in relation to a compound or composition, it means "weight % (wt.%)" or "weight % (% by wt.)".

[0043] As used herein, the term "monomer" generally refers to nonionic monomers, anionic monomers, cationic monomers, zwitterionic monomers, betaine monomers, and zwitterionic pair monomers.

[0044] As used herein, the terms "polymer", "polymers", "polymeric" and like terms are used in their ordinary meaning as understood by one of ordinary skill in the art and can thus be used herein to refer to or describe macromolecules (or a group of such molecules) containing repeating units. Polymers can be formed in various ways, including by polymerizing monomers and / or by chemically modifying one or more repeating units of a precursor polymer. Unless otherwise indicated, polymers can include "homopolymers", which can contain substantially the same repeating units that can be formed by various methods, such as by polymerizing a specific monomer. Unless otherwise indicated, polymers can also include "copolymers", which can contain two or more different repeating units that can be formed, for example, by copolymerizing two or more different monomers and / or by chemically modifying one or more repeating units of a precursor polymer. Unless otherwise indicated, polymers or copolymers can also include "terpolymers", which can include polymers that can contain three or more different repeating units. As used herein, the term "polymer" is intended to include the acid form of the polymer as well as its various salts. Polymers can be amphoteric in nature, i.e., contain anionic and cationic substituents, although not necessarily in the same proportions.

[0045] As used herein, the term "nonionic monomer" generally refers to monomers having a neutral charge.

[0046] As used herein, the term "anionic monomer" can refer to anionic monomers that are substantially all or partially (at equilibrium) anionic at a pH in the range of about 4.0 to about 9.0. "Anionic monomers" can be neutral at low pH values (pH of about 2 to about 6), or can be anionic monomers that are anionic at low pH. In some embodiments, anionic monomers, such as vinyl monomers, can include, but are not limited to, those containing carboxylic acid functional groups, sulfonic acid functional groups, phosphonic acid functional groups, and their corresponding water-soluble salts, and any combination thereof. In some embodiments, anionic monomers can include acrylic acid, methacrylic acid, maleic acid, itaconic acid, vinyl sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), acrylamidomethanesulfonic acid, acrylamidoethanesulfonic acid, 2-hydroxy-3-acrylamidopropanesulfonic acid, styrenesulfonic acid, vinylphosphonic acid, and combinations thereof, as well as their corresponding water-soluble or dispersible alkali metal salts, alkaline earth metal salts, and ammonium salts, and any combination thereof. In some embodiments, the cationic GPAM composition can contain a base polymer that is optionally amphoteric, i.e., a base polymer containing both cationic monomers and anionic monomers.

[0047] As used herein, the term "cationic monomer" generally refers to a monomer having a positive charge. Examples of cationic monomers can include, but are not limited to, those containing acryloyloxyethyl trimethylammonium chloride ("AETAC"), methacryloyloxyethyl trimethylammonium chloride, methacrylamidopropyl trimethylammonium chloride ("MAPTAC"), acrylamidopropyl trimethylammonium chloride, methacryloyloxyethyl dimethyl sulfate, dimethylaminoethyl acrylate, dimethylaminopropyl methacrylamide, methacryloyloxyethyl trimethylammonium chloride methacrylic acid dimethylaminoethyl ester sulfate and / or diallyldimethylammonium chloride ("DADMAC"). The cationic monomers can also include, but are not limited to, those including dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates and their quaternary salts or acid salts, including but not limited to dimethylaminoethyl acrylate methyl chloride quaternary salt ("DMAEA.MCQ"), dimethylaminoethyl acrylate methyl sulfate quaternary salt ("DMAEM.MCQ"), dimethylaminoethyl acrylate benzyl chloride quaternary salt ("DMAEA.BCQ"), dimethylaminoethyl acrylate sulfate, dimethylaminoethyl acrylate hydrochloride, diethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfate, dimethylaminoethyl methacrylate hydrochloride, dimethylaminoethyl methacryloyl hydrochloride; dialkylaminoalkyl acrylamides or dialkylaminoalkyl methacrylamides and their quaternary ammonium salts or acid salts, such as acrylamidopropyl trimethylammonium chloride, dimethylaminopropyl acrylamide methyl sulfate quaternary salt, dimethylaminopropyl acrylamide sulfate, dimethylaminopropyl acrylamide hydrochloride, methacrylamidopropyl trimethylammonium chloride, dimethylaminopropyl methacrylamide methyl sulfate quaternary salt, dimethylaminopropyl methacrylamide sulfate, dimethylaminopropyl methacrylamide hydrochloride, diethylaminoethyl acrylate, diethylaminoethyl methacrylate; and diallyldialkylammonium halides, such as diallyldiethylammonium chloride and diallyldimethylammonium chloride. The alkyl group can generally include, but is not limited to, those containing C 1-8 alkyl groups. In some embodiments, the cationic monomer can include quaternary ammonium salts or acid salts of vinyl amides, vinyl carboxylic acids, methacrylates and their derivatives. The cationic monomers can be combined, for example, to form a terpolymer of dimethylaminoethyl methacrylate methyl chloride quaternary salt, diallyldimethylammonium chloride and acrylamide.

[0048] As used herein, the term "percent glyoxalation" refers to the percentage of glyoxalated acrylamide monomers in the polymer of the cationic GPAM composition, such as the first base polymer and / or the second base polymer.

[0049] As used herein, the term "GPAM content" refers to the sum of the glyoxylated base polymer plus free glyoxal in a cationic GPAM composition.

[0050] As used herein, the terms "papermaking method" and "papermaking application" generally refer to any method in which paper and / or paperboard products in any form can be produced. For example, such methods include manufacturing paper products from pulp, such as methods including forming an aqueous cellulose papermaking furnish, discharging the furnish to form a paper sheet, and drying the paper sheet. The steps of forming the papermaking furnish, discharging, and drying can be carried out in any conventional manner commonly known in the art.

[0051] As used herein, the term "polyacrylamide" or "PAM" generally refers to polymers and copolymers containing acrylamide moieties, and the term encompasses any polymer or copolymer containing acrylamide moieties, such as one or more acrylamide (co)polymers. In some cases, PAM can include anionic PAMs (APAM), cationic PAM (CPAM), and / or sulfonated PAM (SPAM). In some embodiments, the polyacrylamide can be a cationic polyacrylamide (cPAM).

[0052] As used herein, the term "glyoxylated polyacrylamide" ("GPAM") generally refers to a polymer obtained by reacting glyoxal with a polyacrylamide base polymer. Methods for producing glyoxylated polyacrylamides are known in the art. (See, for example, U.S. Patent No. 3,556,932, which first disclosed the synthesis of GPAM compositions prepared by reacting glyoxal with cationic polyacrylamides). In some cases, the polyacrylamide backbone of GPAM can incorporate a small amount of cationic monomers to cause the polymer to self-retain on fibers. Generally, GPAM contains a reactive polymer that can covalently bond to cellulose upon dehydration.

[0053] The present invention provides cationic GPAM compositions having specific properties, which are highly suitable for papermaking processes, namely as additives for increasing the wet strength and / or dry strength of paper; and which have enhanced storage and transportation properties. For example, unlike conventional GPAMs used in papermaking processes, the cationic GPAMs of the present invention can be stored and transported without the addition of large amounts of aqueous carriers, which are undesirable and expensive as they typically require large-volume containers or tankers for transportation. In some cases, the aqueous carrier may contain water. In some cases, the volume of the aqueous carrier used during the transportation of the cationic GPAMs discussed herein may be less than the volume of the aqueous carrier used for transporting conventional GPAMs. For example, in some cases, conventional GPAMs may contain a solids percentage of 4% or less, while in some embodiments, the cationic GPAM compositions may contain a solids percentage greater than 4%, i.e., greater than 4% to about 11%, such as about greater than 4% to about 9%, about greater than 5% to about 8%, or about 6% to about 7.5%.

[0054] As used herein, the term "cationic GPAM" or "cationic GPAM composition" generally refers to a GPAM composition comprising a first base polymer having a weight-average molecular weight of less than 30,000 Da and a second base polymer having a weight-average molecular weight of at least 30,000 Da, wherein the weight ratio of the first base polymer to the second base polymer is from about 10:90 to about 90:10, optionally from about 20:80 to about 80:20, optionally from about 30:70 to about 70:30, wherein each of the first base polymer and the second base polymer is glyoxalated, and wherein optionally, compared to the volume of the aqueous carrier required for conventional GPAM used in papermaking, the cationic GPAM composition requires a reduced volume of aqueous carrier for storage or transportation. In some embodiments, the weight-average molecular weight of the first base polymer can be at most 25 kDa or less, 20 kDa or less, 15 kDa or less, 10 kDa or less, or 8 kDa or less. In some embodiments, the weight-average molecular weight of the second base polymer can be at least 30 kDa or greater, 40 kDa or greater, 50 kDa or greater, 75 kDa or greater, 100 kDa or greater, 125 kDa or greater, 150 kDa or greater, 175 kDa or greater, 200 kDa or greater, 225 kDa or greater, 250 kDa or greater, 275 kDa or greater, 300 kDa or greater, 325 kDa or greater, 350 kDa or greater, 375 kDa or greater, 400 kDa or greater, or 500 kDa or greater. In some embodiments, the glyoxalation percentage of the cationic GPAM composition can be from about 2% to about 90%, optionally from about 3% to about 80%, further optionally from about 4% to about 70%, further optionally from about 5% to about 60%. In some embodiments, the glyoxalation percentage of the first base polymer can be from about 2% to about 90%, optionally from about 3% to about 80%, further optionally from about 4% to about 70%, further optionally from about 5% to about 60%. In some embodiments, the glyoxalation percentage of the second base polymer can be from about 2% to about 90%, optionally from about 3% to about 80%, further optionally from about 4% to about 70%, further optionally from about 5% to about 60%. In some embodiments, the GPAM content of the cationic GPAM composition can be from about 2% to about 20%, optionally from about 3% to about 10%, further optionally from about 4% to about 8%, further optionally from about 5% to about 7%. In some embodiments, the GPAM content of the first base polymer can be from about 2% to about 20%, optionally from about 3% to about 10%, further optionally from about 4% to about 8%, further optionally from about 5% to about 7%.In some embodiments, the GPAM content of the second base polymer can be from about 2% to about 20%, optionally from about 3% to about 10%, further optionally from about 4% to about 8%, and further optionally from about 5% to about 7%. In some embodiments, the first base polymer can comprise at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 50 wt% or at least 60 wt% of cationic charge, where optionally the first base polymer is amphoteric. In some embodiments, the second base polymer can comprise at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 50 wt% or at least 60 wt% of cationic charge, where optionally the second base polymer is amphoteric. In some embodiments, the first base polymer can comprise at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 50 wt% or at least 60 wt% of cationic monomer percentage, where optionally the first base polymer can be amphoteric. In some embodiments, the second base polymer can comprise at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 50 wt% or at least 60 wt% of cationic monomer percentage, where optionally the second base polymer can be amphoteric. In some embodiments, the cationic GPAM composition can comprise a solids weight percentage of about 1.0% or greater, 2.0% or greater, 3.0% or greater, 4.0% or greater, 5.0% or greater, 5.5% or greater, 6.0% or greater, 6.5% or greater, 7.0% or greater, 7.5% or greater, 8.0% or greater, 8.5% or greater, 9.0% or greater, 9.5% or greater, 10.0% or greater, 10.5% or greater, 11.0% or greater, or 11.5% or greater. In some embodiments, the cationic GPAM composition can comprise a solids weight percentage of from about 1.0% to about 20.0%, optionally from about 3.0% to about 15%.In some embodiments, the cationic GPAM composition may comprise a glyoxal to total base polymer weight ratio of at least about 1:99, at least about 2.5:97.5, at least about 5:95, at least about 7.5:92.5, at least about 10:90, at least about 12.5:87.5, at least about 15:85, at least about 17.5:82.5, at least about 20:80, at least about 22.5:77.5, at least about 25:75, at least about 27.5:72.5, at least about 29:71 or at least about 30:70. In some embodiments, the first base polymer may comprise an acrylamide-based polymer. In some embodiments, the second base polymer may comprise an acrylamide-based polymer. In some embodiments, the first base polymer may comprise one or more cationic monomers. In some embodiments, the second base polymer may comprise one or more cationic monomers. In some embodiments, the first base polymer may comprise a cationic monomer:acrylamide weight ratio of from about 15:85 to about 60:40, optionally from about 20:80 to about 55:45, and further optionally from about 25:75 to about 50:50. In some embodiments, the second base polymer may comprise a cationic monomer:acrylamide weight ratio of from about 15:85 to about 60:40, optionally from about 20:80 to about 55:45, and further optionally from about 25:75 to about 50:50. In some embodiments, the first base polymer is amphoteric and comprises more cationic monomers than anionic monomers. In some embodiments, the second base polymer is amphoteric and comprises more cationic monomers than anionic monomers. In some embodiments, the first base polymer may comprise a copolymer of acrylamide or methacrylamide and one or more cationic monomers. In some embodiments, the second base polymer may comprise a copolymer of acrylamide or methacrylamide and one or more cationic monomers. In some embodiments, the one or more cationic monomers may include DADMAC and / or may include acryloyloxyethyl trimethyl ammonium chloride (aka Q9). In some embodiments, the backbone polymer may comprise an acrylamide-based polymer, wherein the acrylamide monomer is replaced by other primary amide-containing monomers such as methacrylamide, ethylacrylamide, crotonamide, N-methylacrylamide, N-butylacrylamide or N-ethylmethylacrylamide or any combination thereof. In some embodiments, the backbone polymer may comprise acrylamide monomers. In some embodiments, the viscosity of the cationic GPAM composition may be about 10 cPs or greater, about 15 cPs or greater, about 20 cPs or greater, about 25 cPs or greater, about 30 cPs or greater, or about 35 cPs or greater, for example, measured using a No. 1 spindle with an LV Brookfield viscometer at 25 °C and 600 rpm.The cationic GPAM compositions described herein can be used in any papermaking process as further described herein. In addition, the cationic GPAM compositions described herein have properties that reduce transportation and manufacturing costs, thereby providing benefits to manufacturers and end users of the cationic GPAM compositions.

[0055] As used herein, the term "white water" generally refers to process water and / or production water that can be removed from a pulp furnish during the formation of a paper product, such as paper, e.g., hand sheets.

[0056] Compositions and Methods

[0057] I. Cationic GPAM Compositions

[0058] GPAM compositions have known uses in the papermaking industry, typically as wet and / or dry strength agents. However, conventional GPAMs generally need to be stored and transported in large volumes of bulk aqueous carrier fluids, which typically require large volume containers or tankers for transportation. Transporting such large quantities of product significantly increases the cost of transporting and using GPAM compositions. Accordingly, there is a need for improved GPAM compositions, such as those containing cationic GPAMs, which are based on their composition suitable for papermaking processes and which have storage properties that should result in reduced transportation costs.

[0059] To that end, the present disclosure generally relates to improved glyoxalated polyacrylamide (GPAM) compositions suitable for use as dry and / or wet strength agents, wherein the cationic GPAM composition comprises a first base polymer having a weight average molecular weight of less than 30,000 Da and a second base polymer having a weight average molecular weight of at least 30,000 Da, wherein the weight ratio of the first base polymer to the second base polymer is from about 10:90 to about 90:10, optionally from about 20:80 to about 80:20, further optionally from about 30:70 to about 70:30, wherein the first base polymer and the second base polymer are each glyoxalated, the composition is suitable for use in papermaking processes and has improved storage properties that should result in reduced transportation costs, further optionally, wherein the cationic GPAM composition requires a reduced volume of aqueous carrier for storage or transportation compared to the volume of aqueous carrier required for conventional GPAMs used in papermaking. For example, the volume of aqueous carrier used during transportation of the cationic GPAM compositions discussed herein can be less than the volume of aqueous carrier used for transporting conventional GPAMs. For example, in some cases, conventional GPAMs can contain a solids percentage of 4% or less, while in some embodiments, the cationic GPAM composition can contain greater than 4%, i.e., greater than 4% to about 11%, such as about greater than 5% to about 9%, such as about greater than 5% to about 8% or about 6% to about 7.5% solids percentage.

[0060] In some embodiments, the cationic GPAM composition may comprise a first base polymer having a weight average molecular weight of at most 25 kDa or less, 20 kDa or less, 15 kDa or less, 10 kDa or less, or 8 kDa or less. In some embodiments, the cationic GPAM may comprise a second base polymer having a weight average molecular weight of at least 30 kDa or greater, 40 kDa or greater, 50 kDa or greater, 75 kDa or greater, 100 kDa or greater, 125 kDa or greater, 150 kDa or greater, 175 kDa or greater, 200 kDa or greater, 225 kDa or greater, 250 kDa or greater, 275 kDa or greater, 300 kDa or greater, 325 kDa or greater, 350 kDa or greater, 375 kDa or greater, 400 kDa or greater, or 500 kDa or greater.

[0061] In some embodiments, the glyoxalation percentage of the cationic GPAM composition may be from about 2% to about 90%, optionally from about 3% to about 80%, further optionally from about 4% to about 70%, and further optionally from about 5% to about 60%. In some embodiments, the glyoxalation percentage of the first base polymer may be from about 2% to about 90%, optionally from about 3% to about 80%, further optionally from about 4% to about 70%, and further optionally from about 5% to about 60%. In some embodiments, the glyoxalation percentage of the second base polymer may be from about 2% to about 90%, optionally from about 3% to about 80%, further optionally from about 4% to about 70%, and further optionally from about 5% to about 60%.

[0062] In some embodiments, the range of the weight average molecular weight of the first base polymer does not exceed 2 to 25 kDa, 5 - 20 kDa, or 5 - 15 kDa.

[0063] In some embodiments, the range of the weight average molecular weight of the second base polymer is at least 100 kDa to 500 kDa, 150 - 400 kDa, 200 - 300 kDa, 225 kDa to 275 kDa, or is about 250 kDa.

[0064] In some embodiments, either or both of the first base polymer and the second base polymer comprise a copolymer of a first monomer including acrylamide or methacrylamide and a second monomer including DADMAC (dimethyl diallyl ammonium chloride) or Q9, optionally wherein the first monomer includes acrylamide and the second monomer includes DADMAC, and wherein the range of the percentages of the first monomer and the second monomer is from about 30:70 to about 70:30.

[0065] In some embodiments, either or both of the first base polymer and the second base polymer comprise a copolymer of a first monomer comprising acrylamide or methacrylamide and a second monomer comprising DADMAC (dimethyl diallyl ammonium chloride) or Q9, optionally wherein the first monomer comprises acrylamide and the second monomer comprises DADMAC, wherein the percentages of the first monomer and the second monomer range from about 40:60 to about 60:40, or are about 40:60.

[0066] In some embodiments, in the glyoxylation reaction for producing the glyoxylated first base polymer and the second base polymer, the glyoxylated base polymer ratio ranges from 10:90 to 90:10, 20:80 to 80:20, 30:70 to 70:30, or includes about 30:70.

[0067] In some embodiments, the ratio of the first base polymer to the second base polymer ranges from 20:80 to 80:20, 30:70 to 70:30, or 40:60 to 60:40.

[0068] In some embodiments, either or both of the first base polymer and the second base polymer comprise a copolymer of acrylamide and DADMAC (dimethyl diallyl ammonium chloride), wherein the percentages of the acrylamide and DADMAC monomers range from about 40:60 to about 60:40; and the ratio of the first base polymer to the second base polymer in the enhancer ranges from 20:80 to 80:20, 30:70 to 70:30, or 40:60 to 60:40.

[0069] In some embodiments, both the first base polymer and the second base polymer comprise a copolymer of acrylamide and DADMAC, the weight average molecular weight of the first base polymer ranges up to 2 to 25 kDa, 5 - 20 kDa or 5 - 15 kDa; the weight average molecular weight of the second base polymer ranges from at least 100 kDa to 500 kDa, 150 - 400 kDa, 200 - 300 kDa, 225 kDa to 275 kDa, or is about 250 kDa; and the ratio of the first base polymer to the second base polymer ranges from 20:80 to 80:20, 30:70 to 70:30, or 40:60 to 60:40.

[0070] In some embodiments, the GPAM content of the cationic GPAM composition can be from about 2% to about 20%, optionally from about 3% to about 10%, further optionally from about 4% to about 8%, and further optionally from about 5% to about 7%. In some embodiments, the GPAM content of the first base polymer can be from about 2% to about 20%, optionally from about 3% to about 10%, further optionally from about 4% to about 8%, and further optionally from about 5% to about 7%. In some embodiments, the GPAM content of the second base polymer can be from about 2% to about 20%, optionally from about 3% to about 10%, further optionally from about 4% to about 8%, and further optionally from about 5% to about 7%.

[0071] In some embodiments, the first base polymer can comprise at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 50 wt% or at least 60 wt% of cationic charge, wherein optionally the first base polymer is amphoteric. In some embodiments, the second base polymer can comprise at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 50 wt% or at least 60 wt% of cationic charge, wherein optionally the second base polymer is amphoteric.

[0072] In some embodiments, the first base polymer can comprise at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 50 wt% or at least 60 wt% of cationic monomer percentage, wherein optionally the first base polymer can be amphoteric. In some embodiments, the second base polymer can comprise at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 50 wt% or at least 60 wt% of cationic monomer percentage, wherein optionally the second base polymer can be amphoteric.

[0073] In some embodiments, the cationic GPAM composition may comprise a solids weight percentage of about 1.0% or greater, 2.0% or greater, 3.0% or greater, 4.0% or greater, 5.0% or greater, 5.5% or greater, 6.0% or greater, 6.5% or greater, 7.0% or greater, 7.5% or greater, 8.0% or greater, 8.5% or greater, 9.0% or greater, 9.5% or greater, 10.0% or greater, 10.5% or greater, 11.0% or greater, or 11.5% or greater. In some embodiments, the cationic GPAM composition may comprise a solids weight percentage of from about 1.0% to about 20.0%, optionally from about 3.0% to about 15%.

[0074] In some embodiments, the cationic GPAM composition may comprise a glyoxal to total base polymer weight ratio of at least about 1:99, at least about 2.5:97.5, at least about 5:95, at least about 7.5:92.5, at least about 10:90, at least about 12.5:87.5, at least about 15:85, at least about 17.5:82.5, at least about 20:80, at least about 22.5:77.5, at least about 25:75, at least about 27.5:72.5, at least about 29:71 or at least about 30:70.

[0075] In some embodiments, the first base polymer may comprise an acrylamide-based polymer. In some embodiments, the second base polymer may comprise an acrylamide-based polymer. In some embodiments, the first base polymer may comprise one or more cationic monomers. In some embodiments, the second base polymer may comprise one or more cationic monomers. Those skilled in the art will be able to readily determine the appropriate cationic monomer:acrylamide weight ratio for the first base polymer and / or the second base polymer. For example, in some embodiments, the first base polymer may comprise a cationic monomer:acrylamide weight ratio of from about 15:85 to about 60:40, optionally from about 20:80 to about 55:45, and further optionally from about 25:75 to about 50:50. For example, in some embodiments, the second base polymer may comprise a cationic monomer:acrylamide weight ratio of from about 15:85 to about 60:40, optionally from about 20:80 to about 55:45, and further optionally from about 25:75 to about 50:50. In some embodiments, the first base polymer is amphoteric and comprises more cationic monomers than anionic monomers. In some embodiments, the second base polymer is amphoteric and comprises more cationic monomers than anionic monomers. In some embodiments, the first base polymer may comprise a copolymer of acrylamide or methacrylamide and one or more cationic monomers. In some embodiments, the second base polymer may comprise a copolymer of acrylamide or methacrylamide and one or more cationic monomers.

[0076] In some embodiments, the viscosity of the cationic GPAM composition may be about 10 cPs or greater, about 15 cPs or greater, about 20 cPs or greater, about 25 cPs or greater, about 30 cPs or greater, or about 35 cPs or greater, for example, measured using spindle 1 with an LV Brookfield viscometer at 25 °C and 600 rpm.

[0077] In some embodiments, the cationic monomers of the first base polymer and the second base polymer of the cationic GPAM composition may include any one or more of the cationic monomers described herein. In some embodiments, the one or more cationic monomers may each independently be selected from the group consisting of acryloyloxyethyl trimethylammonium chloride (“AETAC”), methacryloyloxyethyl trimethylammonium chloride, methacrylamidopropyl trimethylammonium chloride (“MAPTAC”), acrylamidopropyl trimethylammonium chloride, methacryloyloxyethyl dimethyl sulfate, dimethylaminoethyl acrylate, dimethylaminopropyl methacrylamide, methacryloyloxyethyl trimethylammonium chloride methacrylic acid dimethylaminoethyl ester sulfate, diallyldimethylammonium chloride (“DADMAC”); dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates and their quaternary salts or acid salts, including but not limited to dimethylaminoethyl acrylate methyl chloride quaternary salt (“DMAEA.MCQ”), dimethylaminoethyl acrylate methyl sulfate quaternary salt (“DMAEM.MCQ”), dimethylaminoethyl acrylate benzyl chloride quaternary salt (“DMAEA.BCQ”), dimethylaminoethyl acrylate sulfate, dimethylaminoethyl acrylate hydrochloride, diethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfate, dimethylaminoethyl methacrylate hydrochloride, dimethylaminoethyl methacryloyl hydrochloride; dialkylaminoalkyl acrylamides or dialkylaminoalkyl methacrylamides and their quaternary ammonium salts or acid salts, such as acrylamidopropyl trimethylammonium chloride, dimethylaminopropyl acrylamide methyl sulfate quaternary salt, dimethylaminopropyl acrylamide sulfate, dimethylaminopropyl acrylamide hydrochloride, methacrylamidopropyl trimethylammonium chloride, dimethylaminopropyl methacrylamide methyl sulfate quaternary salt, dimethylaminopropyl methacrylamide sulfate, dimethylaminopropyl methacrylamide hydrochloride, diethylaminoethyl acrylate, diethylaminoethyl methacrylate; and diallyldialkylammonium halides, such as diallyldiethylammonium chloride and diallyldimethylammonium chloride. In some embodiments, the one or more cationic monomers may include DADMAC. In some embodiments, the one or more cationic monomers may include acryloyloxyethyl trimethylammonium chloride (“Q9”). In some embodiments, the one or more cationic monomers may each independently include DADMAC and / or acryloyloxyethyl trimethylammonium chloride (“Q9”).In some embodiments, the one or more cationic monomers may each independently be selected from the group consisting of methacryloyloxyethyl trimethyl ammonium chloride, acryloyloxyethyl trimethyl ammonium chloride (also known as Q9), 3-(methacrylamido)propyl trimethyl ammonium chloride, 3-(acrylamido)propyl trimethyl ammonium chloride, diallyl dimethyl ammonium chloride (DADMAC), dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, and dimethylaminopropyl acrylamide, dimethylaminopropyl methacrylamide.

[0078] In some embodiments, the acrylamide-based polymers of the first base polymer and the second base polymer may each independently comprise one or more monomers containing a primary amide. In some embodiments, the acrylamide-based polymer may comprise one or more monomers selected from the group consisting of acrylamide, methacrylamide, ethylacrylamide, crotonamide, N-methylmethacrylamide, N-butylacrylamide, N-ethylmethylacrylamide, and any combination thereof. In some embodiments, the acrylamide-based polymer may comprise one or more acrylamide monomers.

[0079] Compared to conventional GPAM, the properties of such cationic GPAM compositions, such as cationic charge, cationic monomer percentage, solids percentage, GPAM content, and / or glyoxalation percentage, demonstrate desirable and effective end-use performance, and the properties of the cationic GPAM disclosed and illustrated herein should translate to a significant reduction in the volume of product that needs to be transported and handled, e.g., in cases involving rail tank car or tanker truck transportation, etc., and thus significant cost and handling savings can be achieved by using the cationic GPAM of the present invention.

[0080] In some embodiments, the cationic GPAM, i.e., the cationic polyacrylamide of the first base polymer and / or the second base polymer, may comprise a cationic copolymer of acrylamide or methacrylamide (cPAM). In some embodiments, the cPAM may comprise a cationic copolymer of acrylamide or methacrylamide, which may be prepared by copolymerizing acrylamide or methacrylamide with one or more cationic monomers. In some embodiments, the one or more cationic monomers may include any one or more of the cationic monomers discussed herein. In some embodiments, the one or more cationic monomers may include, but are not limited to, methacryloyloxyethyl trimethyl ammonium chloride, acryloyloxyethyl trimethyl ammonium chloride (also known as Q9), 3-(methacrylamido)propyl trimethyl ammonium chloride, 3-(acrylamido)propyl trimethyl ammonium chloride, diallyl dimethyl ammonium chloride (DADMAC), dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, dimethylaminopropyl acrylamide, dimethylaminopropyl methacrylamide, and similar monomers. In some embodiments, the cationic GPAM may comprise a cationic monomer that includes any one or more of 2-vinylpyridine, 2-vinyl-N-methylpyridinium chloride, (p-vinylphenyl)trimethyl ammonium chloride, diallyl dimethyl ammonium chloride, 2-(dimethylamino)ethyl acrylate, trimethyl(p-vinylbenzyl)ammonium chloride, p-dimethylaminoethyl styrene, dimethylaminopropyl acrylamide, 2-methacryloyloxyethyl trimethyl methyl sulfate, or 3-acrylamido-3-methylbutyl trimethyl ammonium chloride, or any combination thereof. In some embodiments, the cPAM may comprise a copolymer of acrylamide or methacrylamide and DADMAC. In some embodiments, the cPAM may comprise a copolymer of acrylamide or methacrylamide and Q9. In some embodiments, the cPAM may comprise one or more cationic monomers (such as those discussed herein), a cationic net charge, and an acrylamide or methacrylamide backbone. In some embodiments, the cPAM may comprise an acrylamide-based polymer or a methacrylamide-based polymer, which is treated, for example, by using Hofmann or Mannich reaction after polymerization to make it cationic. In some embodiments, the cPAM may comprise a cationic copolymer of acrylamide or methacrylamide, which may be prepared by conventional free radical initiated polymerization methods.

[0081] In some embodiments, the backbone polymer (e.g., the backbone of the first base polymer and / or the backbone of the second base polymer) may comprise an acrylamide-based polymer, wherein the acrylamide monomer is replaced by other primary amide-containing monomers such as methacrylamide, ethylacrylamide, crotonamide, N-methylacrylamide, N-butylacrylamide, or N-ethylmethacrylamide or any combination thereof. In some embodiments, the backbone polymer may comprise acrylamide monomers. In some embodiments, the one or more cationic monomers may be selected from the group consisting of acryloyloxyethyltrimethylammonium chloride (“AETAC”), methacryloyloxyethyltrimethylammonium chloride, methacrylamidopropyltrimethylammonium chloride (“MAPTAC”), acrylamidopropyltrimethylammonium chloride, methacryloyloxyethyldimethylammonium sulfate, dimethylaminoethyl acrylate, dimethylaminopropylmethacrylamide, methacryloyloxyethyltrimethylammonium chloride methacrylic acid dimethylaminoethyl ester sulfate, diallyldimethylammonium chloride (“DADMAC”); dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates and their quaternary or acid salts, including but not limited to dimethylaminoethyl acrylate methyl chloride quaternary salt (“DMAEA.MCQ”), dimethylaminoethyl acrylate methyl sulfate quaternary salt (“DMAEM.MCQ”), dimethylaminoethyl acrylate benzyl chloride quaternary salt (“DMAEA.BCQ”), dimethylaminoethyl acrylate sulfate, dimethylaminoethyl acrylate hydrochloride, diethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfate, dimethylaminoethyl methacrylate hydrochloride, dimethylaminoethyl methacryloyl hydrochloride; dialkylaminoalkyl acrylamides or dialkylaminoalkyl methacrylamides and their quaternary ammonium or acid salts, such as acrylamidopropyltrimethylammonium chloride, dimethylaminopropylacrylamide methyl sulfate quaternary salt, dimethylaminopropylacrylamide sulfate, dimethylaminopropylacrylamide hydrochloride, methacrylamidopropyltrimethylammonium chloride, dimethylaminopropylmethacrylamide methyl sulfate quaternary salt, dimethylaminopropylmethacrylamide sulfate, dimethylaminopropylmethacrylamide hydrochloride, diethylaminoethyl acrylate, diethylaminoethyl methacrylate; and diallyldialkylammonium halides, such as diallyldiethylammonium chloride and diallyldimethylammonium chloride.In an exemplary embodiment, the first base polymer or the second base polymer comprises or consists of: (i) a first monomer comprising acrylamide and / or methacrylamide; and (ii) a second monomer comprising DADMAC or Q9 monomer, and wherein optionally the percentages of the first monomer and the second monomer range from about 30:70 to about 70:30 or from 40:60 to about 60:40.

[0082] II. Method of using the cationic GPAM composition

[0083] Based on the foregoing, the present disclosure generally also relates to a papermaking method, wherein the method comprises adding one or more of the cationic GPAM compositions as described above, the cationic GPAM compositions being useful in the papermaking method based on their composition and further having storage properties that should result in reduced transportation costs; the method generally comprises adding one or more such cationic GPAM compositions in an amount effective to increase the wet strength and / or dry strength of the paper during the papermaking method. In some embodiments, before forming the paper product, the one or more cationic GPAM compositions are added to a composition comprising fibers and / or pulp used in the method. In some embodiments, after forming the paper product, the one or more cationic GPAM compositions are added to one or more surfaces of the paper product. In some embodiments, the cationic GPAM composition may comprise any one or more of the cationic GPAM compositions disclosed herein. In some embodiments, the cationic GPAM composition may comprise a first base polymer having a weight average molecular weight of less than 30,000 Da and a second base polymer having a weight average molecular weight of at least 30,000 Da, optionally wherein the first base polymer and the second base polymer comprise or consist of: (i) a first monomer comprising acrylamide and / or methacrylamide; and (ii) a second monomer comprising DADMAC or Q9 monomer, further optionally wherein the weight ratio of the first base polymer to the second base polymer is from about 10:90 to about 90:10, optionally from about 20:80 to about 80:20, further optionally from about 30:70 to about 70:30 or from about 40:60 to about 60:40, and wherein the first base polymer and the second base polymer are each glyoxylated.

[0084] In some embodiments, the cationic GPAM compositions described herein provide thermosetting resins that are particularly suitable for use as additives in papermaking methods, i.e., wherein the addition of the cationic GPAM compositions produces paper having a desired dry strength and a temporary wet strength, and / or increases the papermaking dehydration rate.

[0085] In addition, the present disclosure also relates to paper products comprising one or more improved GPAM compositions as disclosed herein. In some embodiments, the paper product may include at least one paper layer or web containing the cationic GPAM composition, such as paper, cardboard, tissue paper, and wallboard. In some embodiments, the paper product comprises the cationic GPAM composition on at least one surface of the paper product. The cationic GPAM composition is not limited to any particular type of paper or papermaking method and should be applied to kraft paper, sulfite paper, semi-chemical paper, etc., including paper produced using bleached pulp, unbleached pulp, or a combination thereof.

[0086] When the cationic GPAM composition as disclosed herein is used during a papermaking method, the cationic GPAM composition can be added at any time before, during, and / or after paper formation. In some cases, the cationic GPAM composition can be added to the cellulose fiber suspension at the wet end of a papermaking facility, typically when conventional wet strength resins are added. In some embodiments, the cationic GPAM composition can be added to a pre-prepared paper, such as to one or more surfaces of a pre-prepared paper, by padding, spraying, dipping, and / or printing, etc. Further, in some embodiments, the cationic GPAM composition can be added to the pulp at a wide range of pH values, such as from about 4 to about 9.

[0087] In some cases, the amount of the cationic GPAM composition added during the papermaking method can range from about 0.02 dry weight % to about 10 dry weight % of the cellulose fibers, such as in the range of about 0.05 weight % to 5 weight % of the dry paper weight.

[0088] Furthermore, the present disclosure generally relates to a paper product, such as hand-sheeted paper, that comprises one or more cationic GPAMs, such as the cationic GPAMs described above, which are useful in a papermaking method based on their composition and optionally have storage properties that should result in reduced shipping costs. In some embodiments, the paper product may include fiber-based products, such as hand-sheeted paper, board-based products, beverage carriers, towels, milk and juice cartons, food trays, paper bags, liners for corrugated boxes, packaging board grades, and tissue and towel grade paper materials, paper towels, diapers, sanitary napkins, training pants, pantiliners, incontinence briefs, tampons, urine pads, bin liners, coffee filter bags, air filtration materials, drying pads, floor cleaning pads, absorbent facial tissues, absorbent toilet paper, napkins, wrapping paper, and / or other cardboard products such as carton and bag paper. In some embodiments, the paper product may include a cellulose cardboard web that comprises: (a) mainly cellulose fibers and (b) one or more cationic GPAM compositions.

[0089] In some embodiments, the paper product may include improved paper strength compared to a paper product that does not contain a cationic GPAM composition, as determined, for example, by the STFI test. For example, in some embodiments, the paper product may include a hand sheet containing one or more cationic GPAM compositions, wherein the hand sheet may include an STFI value improvement of 6% or greater, 7% or greater, 8% or greater, 9% or greater, 10% or greater, 12.5% or greater, 15.0% or greater, 17.5% or greater, 20.0% or greater, 22.5% or greater, 25.0% or greater when tested at 4.5 lbs / ton, 5.0 lbs / ton, 9.0 lbs / ton, or 10 lbs / ton compared to a blank sample used for the STFI test.

[0090] In some embodiments, the paper product may include improved paper strength compared to a paper product that does not contain a cationic GPAM composition, as determined, for example, by the burst strength test. For example, in some embodiments, a hand sheet containing one or more cationic GPAM compositions may include a burst strength value improvement of 6% or greater, 7% or greater, 8% or greater, 9% or greater, 10% or greater, 12.5% or greater, 15.0% or greater, 17.5% or greater, 20.0% or greater, 22.5% or greater, 25.0% or greater, 27.5% or greater, 30.0% or greater, 32.5% or greater, 35.0% or greater, 37.5% or greater, or 40% or greater when tested at 4.5 lbs / ton, 5.0 lbs / ton, 9.0 lbs / ton, or 10 lbs / ton compared to a blank sample used for the burst strength test.

[0091] In some embodiments, the cationic GPAM composition can reduce the drainage time of the treated sample compared to the drainage time without using the cationic GPAM composition. For example, in some embodiments, the cationic GPAM composition can achieve effective drainage, such as the drainage of OCC pulp, compared to drainage without using the cationic GPAM composition, such as showing an improvement in drainage time (e.g., the time to collect a given amount of filtrate from the OCC pulp) of 25.0% or more, 30.0% or more, 35.0% or more, 40.0% or more, 45.0% or more, 50.0% or more, 55.0% or more. In some embodiments, the cationic GPAM composition increases the drainage rate of the treated sample compared to the drainage rate without using the cationic GPAM composition, resulting in an increase in the paper production rate. In some embodiments, the cationic GPAM composition improves the drying energy savings of the papermaking method. Further, compared to the total amount of solids present in a sample without using the cationic GPAM composition, the cationic GPAM composition can achieve a reduction in the total amount of solids present in the treated sample, e.g., a reduction in the total solids present in the filtrate collected from OCC pulp treated with the cationic GPAM composition, e.g., a reduction in the solids content of the white water from the trays or the silos after paper formation, such as an improvement (reduction in solids content) of 15% or more, 17.5% or more, 20.0% or more, 22.5% or more, 25.0% or more, 27.5% or more, 30.0% or more, or 32.5% or more. In some embodiments, the cationic GPAM composition can improve drying energy savings.

[0092] In addition, the present disclosure generally relates to a method of making a handsheet, the method comprising: a. providing a pulp slurry; b. diluting the pulp slurry; c. adding one or more salts to a desired conductivity level; d. adjusting the pH to a desired value; e. adding one or more cationic GPAM compositions; f. adding the treated pulp to a dynamic paper former; g. pressing the paper produced by f.; h. drying the paper; and i. finishing the paper.

[0093] In addition, the present disclosure generally relates to a method of making one or more paper products, wherein the method comprises: a. providing a composition comprising predominantly cellulose fibers; b. adding a predetermined amount of one or more cationic GPAM compositions; and c. forming the desired paper product.

[0094] In addition, the present disclosure generally encompasses a method of manufacturing one or more paper products, such as one or more adsorbent paper products, wherein the method comprises: a. providing a composition comprising any one of softwood fibers, hardwood fibers, recycled fibers, refined fibers, or a mixture of any of the foregoing, in an amount sufficient to form a total furnish of from about 1% to 100% hardwood fibers, softwood fibers, recycled fibers, refined fibers, or a mixture of any of the foregoing; (b) adding a predetermined amount of one or more cationic GPAM compositions as discussed herein; and (c) forming the paper product by drying via one or more drying devices to a desired moisture content level.

[0095] Additionally, the present disclosure generally relates to a method for strengthening paper, the method comprising (i) contacting pulp fibers with a strengthening resin comprising at least one cationic GPAM composition, such as at least one improved cationic GPAM composition disclosed herein, the GPAM composition having specific properties that make it highly suitable for papermaking processes, and (ii) at least partially curing the strengthening resin comprising at least one cationic GPAM composition in a mixture of pulp fibers and the cationic GPAM composition to produce a paper product having enhanced strength.

[0096] III. Method for Preparing Cationic GPAM Composition

[0097] The present disclosure also generally relates to a method for preparing the cationic GPAM compositions disclosed herein, particularly wherein the cationic GPAM composition comprises a first base polymer having a weight average molecular weight of less than 30,000 Da, optionally from 2 to 25 kDa, or 5 to 15 kDa, and a second base polymer having a weight average molecular weight of at least 30,000 Da; optionally a weight average molecular weight of at least 50 kDa or a weight average molecular weight in the range of 100 kDa to 500 kDa, 150 - 400 kDa, 200 - 300 kDa, 225 kDa to 275 kDa, or about 250 kDa; further optionally, wherein the first base polymer and / or the second base polymer comprises (i) acrylamide or methacrylamide monomers and (ii) DADMAC or Q9 monomers, wherein the weight ratio of the first base polymer to the second base polymer is from about 10:90 to about 90:10, optionally from about 20:80 to about 80:20, further optionally from about 30:70 to about 70:30, or from about 40:60 to about 60:40; wherein the first base polymer and the second base polymer are each glyoxalated; and wherein optionally, compared to the volume of the aqueous carrier required for conventional GPAM used in papermaking, the cationic GPAM composition requires a reduced volume of aqueous carrier for storage or transportation.

[0098] In some embodiments, methods for preparing the cationic GPAM compositions disclosed herein may include a. glyoxalating the first base polymer in a first glyoxalation reaction comprising glyoxal to produce a first glyoxalated base polymer; b. glyoxalating the second base polymer in a second glyoxalation reaction comprising glyoxal to produce a second glyoxalated base polymer; and c. combining the first glyoxalated base polymer and the second glyoxalated base polymer to produce the cationic GPAM composition; wherein steps (a) and (b) may be carried out in any order or simultaneously.

[0099] In some embodiments, methods for preparing the cationic GPAM compositions disclosed herein may include a. combining the first base polymer and the second base polymer; and b. glyoxalating the combination of the first base polymer and the second base polymer in a glyoxalation reaction comprising glyoxal to produce the cationic GPAM composition.

[0100] In some embodiments, methods for preparing the cationic GPAM compositions disclosed herein may include a. glyoxalating the first base polymer in a glyoxalation reaction comprising glyoxal to produce a first glyoxalated base polymer; and b. adding the second base polymer and optionally additional glyoxal to the glyoxalation reaction to produce the cationic GPAM composition.

[0101] In some embodiments, methods for preparing the cationic GPAM compositions disclosed herein may include a. glyoxalating the second base polymer in a glyoxalation reaction comprising glyoxal to produce a second glyoxalated base polymer; and b. adding the first base polymer and optionally additional glyoxal to the glyoxalation reaction to produce the cationic GPAM composition.

[0102] In some embodiments, methods for preparing the cationic GPAM compositions disclosed herein may include a. glyoxalating the first base polymer in a first glyoxalation reaction comprising glyoxal to produce a first glyoxalated base polymer; and b. glyoxalating the second base polymer and the first glyoxalated base polymer in a second glyoxalation reaction comprising glyoxal to produce the cationic GPAM composition.

[0103] In some embodiments, methods for preparing the cationic GPAM compositions disclosed herein may include a. glyoxalating the second base polymer in a second glyoxalation reaction comprising glyoxal to produce a second glyoxalated base polymer; and b. glyoxalating the first base polymer and the second glyoxalated base polymer in a first glyoxalation reaction comprising glyoxal to produce the cationic GPAM composition.

[0104] The compositions and methods disclosed herein by way of example may suitably be practiced in the absence of any element not specifically disclosed herein and / or in the presence of any element specifically disclosed herein.

[0105] Examples

[0106] Example 1: Sample and Hand Sheet Preparation

[0107] The cationic GPAM compositions and hand sheet preparations used in the following examples are as follows. All GPAM samples were prepared by reacting glyoxal with the cationic polyacrylamide base polymers shown in Table 1.

[0108] Table 1 - Base Polymer Composition

[0109]

[0110] * Each of base polymers 1, 2, and 3 is a copolymer composed of acrylamide and DADMAC (dimethyl diallyl ammonium chloride) monomers.

[0111] Cationic copolymers containing acrylamide and DADMAC monomers were used in the examples herein because such copolymers are widely used as "model" cationic polymers. Thus, it is reasonably expected that the results obtained using these copolymers will be obtained using other cationic polymers such as cationic copolymers containing other cationic monomers disclosed herein.

[0112] The compositions of the GPAM samples prepared by reacting glyoxal with the base polymers of Table 1 are described in Table 2. For each reaction, the glyoxal:base polymer ratio was 29:71.

[0113] Table 2 - GPAM Sample Composition

[0114]

[0115] GPAM 1, GPAM 2, and GPAM 8 are conventional GPAM compositions. GPAM 1 is prepared using a low molecular weight (8 kDa) base polymer 1 and has a high final solids content (14%), while GPAM 2 is prepared using a high molecular weight (246 kDa) base polymer 3 and has a low final solids content (5%). GPAM 8 is prepared using a low molecular weight (15 kDa) base polymer 2.

[0116] New GPAM compositions 3 to GPAM 7 are prepared using base polymer 1 and base polymer 3 by various methods. GPAM 3 and GPAM 4 are prepared by glyoxalation of a base polymer blend. GPAM 5 and GPAM 6 are simple blends of GPAM 1 and GPAM 2. GPAM 7 is prepared by a two-step reaction. In step 1, GPAM 1 is produced by glyoxalation of base polymer 1. In step 2, base polymer 3 and more glyoxal are added to the final GPAM 1, and a further glyoxalation reaction is carried out to produce the final GPAM 7 composition.

[0117] The new GPAM 3 - GPAM 7 have much higher solids contents than GPAM 2 (5.0%) prepared from base polymer 3. For example, the solids content of GPAM 4 is 7.3%, which is 46% higher than the solids content of GPAM 2. When producing GPAM products with a solids content below 6%, the costs associated with production, transportation, and handling are generally higher than the raw material costs. As a result, a 45% increase in the product solids content leads to a significant reduction in the total product cost.

[0118] New GPAM 9 - GPAM 11 are prepared by carrying out a glyoxalation reaction on a blend mixture of base polymer 2 and base polymer 3. The ratio of base polymer 2:base polymer 3 is as shown in Table 2. As shown in Table 2, GPAM 9, GPAM 10, and GPAM 11 have solids contents of 7.0%, 6.7%, and 7.2% respectively, each of which is significantly higher than the solids content of GPAM 2 (5.0%) prepared from base polymer 3, resulting in a significant reduction in the total product cost.

[0119] The handsheets were prepared using the above GPAM as follows: The OCC pulp thick stock was obtained from a renewable linerboard mill. First, the thick stock was diluted with tap water to a consistency of 0.5%. NaCl was added to the diluted pulp to match the conductivity of the mill white water. Then 1M HCl solution was added to the pulp to adjust the pH to 6.4. Second, the GPAM composition was introduced into the diluted pulp under overhead stirring. Then the treated pulp was added to a dynamic sheet former (DSF) (TECHPAP France, type FDA) to produce 110 gsm paper. Next, the formed paper was pressed with blotting paper at 15 psi using a pneumatic roll press and then dried on a rotary dryer at 110 °C. Then, the dried paper was cured in an oven (forced draft conventional oven) at 105 °C for 5 minutes and then conditioned overnight in a standard TAPPI control room. Finally, strips of paper were cut transversely.

[0120] Example 2: Burst strength test

[0121] The burst strength test was conducted according to TAPPI standard method T - 403. The results are shown in Table 3.

[0122] Table 3 – Burst strength of handsheets treated with various GPAM products

[0123]

[0124]

[0125] As shown in Table 3, each of the new GPAM 3 and GPAM 4 provides dry strength properties comparable to GPAM 2. In addition, these new GPAM products have a much higher solids content than GPAM 2.

[0126] Example 3: STFI test

[0127] The STFI test was conducted according to TAPPI standard method T - 826. The results are shown in Tables 4 and 5.

[0128] Table 4 – STFI strength of handsheets treated with various GPAM products

[0129] 9 lbs / ton sample STFI improvement blank 8.64 NA GPAM 1 10.01 15.9％ GPAM 2 10.61 22.8％ GPAM 5 10.56 22.2％ GPAM 6 10.53 21.9％ GPAM 7 10.65 23.3％

[0130] Table 5 – STFI strength of handsheets treated with various GPAM products

[0131]

[0132] As shown in Table 4, each of the new GPAM 5, GPAM 6, and GPAM 7 provides dry strength performance comparable to that of GPAM 2. Additionally, as discussed above, these new GPAM products have a much higher solids content than GPAM 2.

[0133] Table 5 gives the STFI results for handsheets treated with conventional GPAM 2 and GPAM 8 prepared from base polymer 3 and base polymer 2, respectively, and with new GPAM compositions 9 - GPAM composition 11. Conventional GPAM 2 and GPAM 8 increased the STFI by 8.3% and 3.5%, respectively. In contrast, the new GPAM 9 to GPAM 11 increased the STFI by 8.8%, 12.4%, and 14.4%, respectively. This study clearly shows that new GPAM compositions prepared from blends of base polymer 2 and base polymer 3 can provide comparable or substantial paper strength enhancement compared to conventional GPAMs prepared from base polymer 2 or base polymer 3 alone.

[0134] In the foregoing procedure, various steps have been described. However, it is apparent that various modifications and changes can be made thereto, and additional processes can be implemented without departing from the broader scope of the exemplary process set forth in the appended claims.

Claims

1. A cationic glyoxalated polyacrylamide (cationic GPAM) composition suitable for use as a dry and / or wet strength agent, wherein the cationic GPAM composition comprises: i. A first base polymer having a weight average molecular weight in the range of 8 to 25 kDa before glyoxalation; and ii. A second base polymer having a weight average molecular weight in the range of 50 to 500 kDa before glyoxalation; wherein the weight ratio of the first base polymer to the second base polymer ranges from 10:90 to 90:10; and wherein the first base polymer is glyoxalated and the second base polymer is glyoxalated.

2. The cationic glyoxalated polyacrylamide composition suitable for use as a dry and / or wet strength agent according to claim 1, wherein the cationic GPAM composition comprises an aqueous carrier.

3. The cationic glyoxalated polyacrylamide composition suitable for use as a dry and / or wet strength agent according to claim 1 or 2, wherein: i. The weight-average molecular weight of the first base polymer is from 8 to 20 kDa; ii. The weight-average molecular weight of the second base polymer is from 60 to 500 kDa; iii. The glyoxalation percentage of the cationic GPAM composition is from 2% to 90%; iv. The glyoxalation percentage of the first base polymer is from 2% to 90%; v. The glyoxalation percentage of the second base polymer is from 2% to 90%; vi. The GPAM content of the cationic GPAM composition is from 2% to 20%; vii. The GPAM content of the first base polymer is from 2% to 20%; viii. The GPAM content of the second base polymer is from 2% to 20%; ix. The first base polymer contains at least 5 wt% of cationic monomer percentage; x. The second base polymer contains at least 5 wt% of cationic monomer percentage; xi. The cationic GPAM composition contains at least 1.0% of solid weight percentage; xii. The cationic GPAM composition contains from 1.0% to 20.0% of solid weight percentage; xiii. The cationic GPAM composition contains at least a 1:99 weight ratio of glyoxal to total base polymer; xiv. The first base polymer contains an acrylamide-based polymer; xv. The second base polymer contains an acrylamide-based polymer; xvi. The first base polymer contains one or more cationic monomers; xvii. The second base polymer contains one or more cationic monomers; xviii. The first base polymer is amphoteric and contains more cationic monomers than anionic monomers; xix. The second base polymer is amphoteric and contains more cationic monomers than anionic monomers; xx. The first base polymer contains a copolymer of acrylamide or methacrylamide and one or more cationic monomers; xxi. The first base polymer and / or the second base polymer contains acryloyloxyethyltrimethylammonium chloride or dimethyldiallylammonium chloride (DADMAC) monomers; xxii. The second base polymer contains a copolymer of acrylamide or methacrylamide and one or more cationic monomers; xxiii. The first base polymer and the second base polymer contain a copolymer of acrylamide or methacrylamide monomers and one or more cationic monomers; xxiv. The first base polymer and / or the second base polymer contains a copolymer of (a) acrylamide and / or methacrylamide monomers and acryloyloxyethyltrimethylammonium chloride and / or (b) dimethyldiallylammonium chloride (DADMAC) monomers; xxv. The first base polymer or the second base polymer contains a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; xxvi. The first base polymer and the second base polymer contain a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; xxvii. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers, and the glyoxal:base polymer ratio for the glyoxalation reaction ranges from 10:90 to 90:10; xxviii. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; and the molecular weight of the first base polymer is 25 kDa or less; xxix. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; and the molecular weight of the first base polymer is 25 kDa or less; xxx. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; and the molecular weight of the first base polymer is 25 kDa or less; and the weight ratio of the first base polymer to the second base polymer ranges from 10:90 to 90:10; xxxi. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC); the molecular weight of the first base polymer is 25 kDa or less; the glyoxal:base polymer ratio for the glyoxalation reaction of the first base polymer and / or the second base polymer ranges from 10:90 to 90:10; and the weight ratio of the first base polymer to the second base polymer ranges from 10:90 to 90:10, and the cationic GPAM content ranges from 5% to 7%; xxxii. The viscosity of the cationic GPAM composition is at least 10 cPs, and the viscosity is measured using a No. 1 spindle with an LV Brookfield viscometer at 25 °C and 60 rpm; xxxiii. The cationic GPAM comprises an aqueous carrier, and the aqueous carrier comprises water; xxxiv. The first base polymer comprises at least 5 wt% of cationic monomer percentage, wherein the first base polymer is amphoteric; xxxv. The second base polymer comprises at least 5 wt% of cationic monomer percentage, wherein the second base polymer is amphoteric; and / or xxxvi. A combination of any two or more of (i)-(xxxv).

4. The cationic glyoxalated polyacrylamide composition suitable for use as a dry and / or wet strength agent according to claim 3, wherein, For the cationic GPAM composition according to embodiments (xvi)-(xix): i. Each of the one or more cationic monomers is independently selected from the group consisting of acryloyloxyethyl trimethylammonium chloride (AETAC), methacryloyloxyethyl trimethylammonium chloride, methacrylamidopropyl trimethylammonium chloride (MAPTAC), acrylamidopropyl trimethylammonium chloride, methacryloyloxyethyl dimethylammonium sulfate, dimethylaminoethyl acrylate, methacryloyloxyethyl trimethylammonium chloride methacrylate dimethylaminoethyl sulfate, dimethylaminopropyl methacrylamide, diallyldimethylammonium chloride (DADMAC); dialkylaminoalkyl acrylates, dialkylaminoalkyl methacrylates, and quaternary salts or acid salts of any of the foregoing; ii. The one or more cationic monomers include one or more of the following: dimethylaminoethyl acrylate methyl chloride quaternary salt (DMAEA.MCQ), dimethylaminoethyl acrylate methyl sulfate quaternary salt (DMAEM.MCQ), dimethylaminoethyl acrylate benzyl chloride quaternary salt (DMAEA.BCQ), dimethylaminoethyl acrylate sulfate, dimethylaminoethyl acrylate hydrochloride, diethylaminoethyl acrylate methyl chloride quaternary salt, methacryloyloxyethyl trimethylammonium chloride methyl chloride quaternary salt, methacryloyloxyethyl trimethylammonium chloride methyl sulfate quaternary salt, methacryloyloxyethyl trimethylammonium chloride benzyl chloride quaternary salt, methacryloyloxyethyl trimethylammonium chloride sulfate, methacryloyloxyethyl trimethylammonium chloride hydrochloride, dimethylaminoethyl methacrylamide hydrochloride; dialkylaminoalkyl acrylamides, dialkylaminoalkyl methacrylamides, and acrylamidopropyl trimethylammonium chloride, dimethylaminopropyl acrylamide methyl sulfate quaternary salt, dimethylaminopropyl acrylamide sulfate, dimethylaminopropyl acrylamide hydrochloride, methacrylamidopropyl trimethylammonium chloride, dimethylaminopropyl methacrylamide methyl sulfate quaternary salt, dimethylaminopropyl methacrylamide sulfate, dimethylaminopropyl methacrylamide hydrochloride, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, diallyldiethylammonium chloride, and diallyldimethylammonium chloride; iii. The one or more cationic monomers include DADMAC; iv. The one or more cationic monomers include acryloyloxyethyl trimethylammonium chloride; v. Each of the one or more cationic monomers is independently selected from the group consisting of DADMAC and acryloyloxyethyl trimethylammonium chloride; vi. Each of the one or more cationic monomers is independently selected from the group consisting of methacryloyloxyethyl trimethylammonium chloride, acryloyloxyethyl trimethylammonium chloride, 3-(methacrylamido)propyl trimethylammonium chloride, 3-(acrylamido)propyl trimethylammonium chloride, diallyldimethylammonium chloride (DADMAC), dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, and dimethylaminopropyl acrylamide, dimethylaminopropyl methacrylamide; vii. The anionic monomer is selected from acrylic acid, methacrylic acid, maleic acid, itaconic acid, vinylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), acrylamidomethanesulfonic acid, acrylamidoethanesulfonic acid, 2-hydroxy-3-acrylamidopropanesulfonic acid, styrenesulfonic acid, vinylphosphonic acid, and water-soluble or dispersible alkali metal salts, alkaline earth metal salts, and ammonium salts of any of the foregoing; viii. The first base polymer and / or the second base polymer comprises a copolymer of (a) acrylamide and / or methacrylamide monomers and (b) one or more cationic monomers; ix. The first base polymer and / or the second base polymer comprises a copolymer of (a) acrylamide and / or methacrylamide monomers and (b) one or more cationic monomers, and the (b) one or more cationic monomers include DADMAC and / or acryloyloxyethyltrimethylammonium chloride monomers; and / or x. A combination of any two or more of (i)-(ix).

5. The cationic glyoxalated polyacrylamide composition suitable for use as a dry and / or wet strength agent according to any one of claims 1 to 2, wherein: i. Either or both of the first base polymer and the second base polymer comprise a copolymer of a first monomer and a second monomer, the first monomer including acrylamide or methacrylamide, and the second monomer including DADMAC (dimethyl diallyl ammonium chloride) or acryloyloxyethyltrimethylammonium chloride; ii. The first monomer includes acrylamide and the second monomer includes DADMAC, wherein the percentages of the first monomer and the second monomer range from 30:70 to 70:30; iii. Either or both of the first base polymer and the second base polymer comprise a copolymer of a first monomer and a second monomer, the first monomer including acrylamide or methacrylamide, and the second monomer including DADMAC (dimethyl diallyl ammonium chloride) or acryloyloxyethyltrimethylammonium chloride; iv. The first monomer includes acrylamide and the second monomer includes DADMAC, wherein the percentages of the first monomer and the second monomer range from 40:60 to 60:40; v. In the glyoxylation reaction for producing the glyoxylated first base polymer and the second base polymer, the glyoxal:base polymer ratio ranges from 10:90 to 90:10; vi. The ratio of the first base polymer to the second base polymer in the enhancer ranges from 20:80 to 80:20; vii. Either or both of the first base polymer and the second base polymer comprise a copolymer of acrylamide and DADMAC (dimethyl diallyl ammonium chloride), wherein the percentages of the acrylamide and DADMAC monomers range from 40:60 to 60:40; and the ratio of the first base polymer to the second base polymer in the enhancer ranges from 20:80 to 80:20; or viii. Any combination of two, three, or more of the foregoing.

6. The cationic glyoxalated polyacrylamide composition suitable for use as a dry and / or wet strength agent as claimed in claim 3, wherein, For the cationic GPAM composition according to embodiment (xiv) or (xv): i. The acrylamide-based polymer comprises one or more monomers containing primary amides; ii. The acrylamide-based polymer comprises one or more monomers selected from the group consisting of acrylamide, methacrylamide, ethylacrylamide, crotonamide, N-methylacrylamide, N-butylacrylamide, N-ethylmethacrylamide, and combinations thereof; iii. The acrylamide-based polymer comprises one or more acrylamide monomers; and / or iv. A combination of any two or more of (i)-(iii).

7. The cationic glyoxalated polyacrylamide composition suitable for use as a dry and / or wet strength agent as claimed in claim 3, wherein, For the cationic GPAM composition according to embodiment ix or x: i. The first base polymer and / or the second base polymer is amphoteric and comprises at least one anionic monomer selected from the group consisting of anionic monomers containing a carboxylic acid functional group, a sulfonic acid functional group, or a phosphonic acid functional group; ii. The first base polymer and / or the second base polymer is amphoteric and comprises at least one anionic monomer selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, itaconic acid, vinylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), acrylamidomethanesulfonic acid, acrylamidoethanesulfonic acid, 2-hydroxy-3-acrylamidopropanesulfonic acid, styrenesulfonic acid, vinylphosphonic acid, and water-soluble or dispersible alkali metal salts, alkaline earth metal salts, and ammonium salts of any of the foregoing monomers; and / or iii. A combination of (i) and (ii).

8. A paper product comprising one or more cationic GPAM compositions as claimed in any one of claims 1 to 7.

9. The paper product as claimed in claim 8, wherein in the cationic GPAM composition: i. the first base polymer and the second base polymer comprise a copolymer of acrylamide or methacrylamide and one or more cationic monomers; ii. the first base polymer and / or the second base polymer comprise a copolymer of (a) acrylamide and / or methacrylamide and acryloxyethyltrimethylammonium chloride and / or (b) dimethyldiallylammonium chloride (DADMAC); iii. the first base polymer or the second base polymer comprises a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC); iv. the first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; v. the first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers, and the glyoxal:base polymer ratio for the glyoxalation reaction ranges from 10:90 to 90:10; vi. the first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; the molecular weight of the first base polymer is 25 kDa or less; vii. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; the molecular weight of the first base polymer is 25 kDa or less, and the molecular weight of the second base polymer is at least 50 kDa; and the glyoxal:base polymer ratio for the glyoxalation reaction for glyoxalating the first base polymer and / or the second base polymer ranges from 10:90 to 90:10; viii. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; the molecular weight of the first base polymer is 25 kDa or less, and the molecular weight of the second base polymer is at least 50 kDa; the glyoxal:base polymer ratio for the glyoxalation reaction for the first base polymer and / or the second base polymer ranges from 10:90 to 90:10; and the weight ratio of the first base polymer to the second base polymer ranges from 10:90 to 90:10; or ix. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; the molecular weight of the first base polymer is 25 kDa or less; the glyoxal:base polymer ratio for the glyoxalation reaction for the first base polymer and / or the second base polymer ranges from 10:90 to 90:10; and the weight ratio of the first base polymer to the second base polymer ranges from 10:90 to 90:10, and the cationic GPAM content ranges from 5% to 7%.

10. The paper product according to claim 8 or 9, wherein the paper product: i. comprises at least one paper layer or paper web containing the cationic GPAM composition; ii. contains the cationic GPAM composition on at least one surface of the paper product; iii. comprises one or more of paper, cardboard, tissue paper, and wallboard; iv. comprises one or more of kraft paper, sulfite paper, and semi-chemical paper; v. comprises a fiber-based product; vi. comprises one or more of hand-made paper, board-based products, beverage or food carriers, paper boxes, tissue paper and towel-grade paper products, paper bags, liners for corrugated boxes, packaging board grade, diapers, sanitary napkins, training pants, pantiliners, incontinence briefs, tampons, urine pads, garbage can liners, coffee filter bags, air filtration materials, drying pads, floor cleaning pads; vii. comprises a cellulose cardboard paper web containing cellulose fibers; viii. Comprising cellulose fibers and a cationic GPAM composition of 0.02% to 10% based on the dry weight of the cellulose fibers, or a cationic GPAM composition of 0.05% to 5% by weight based on the dry weight of the cellulose fibers; ix. Comprising improved paper strength compared to a paper product not containing the cationic GPAM composition, said paper strength being determined by the STFI test; x. Comprising improved paper strength compared to a paper product not containing the cationic GPAM composition, said paper strength being determined by the burst strength test; and / or xi. A combination of any two or more of (i)-(x).

11. A papermaking method, wherein the method comprises adding one or more cationic GPAM compositions as described in any one of claims 1 to 7 during the papermaking method, wherein: i. Adding one or more of the cationic GPAM compositions to a composition comprising fibers and / or pulp for producing a paper product; and / or ii. After forming the paper product, adding one or more of the cationic GPAM compositions to one or more surfaces of the paper product.

12. A method for manufacturing one or more paper products, wherein the method comprises: a. Providing a composition comprising cellulose fibers; b. Adding one or more cationic GPAM compositions as described in any one of claims 1 to 7; and c. Forming the desired paper product.

13. A method for manufacturing one or more paper products, wherein the method comprises: a. Providing a composition comprising one or more of softwood fibers, hardwood fibers, recycled fibers, and refined fibers in an amount sufficient to form a total furnish comprising 1% to 100% of one or more of softwood fibers, hardwood fibers, recycled fibers, and refined fibers; (b) adding to it one or more cationic GPAM compositions as described in any one of claims 1 to 7; and (c) forming a paper product by drying.

14. A method for enhancing paper, the method comprising contacting pulp fibers with a strengthening resin comprising at least one cationic GPAM composition as described in any one of claims 1 to 7, and at least partially curing the strengthening resin in contact with the pulp fibers to produce a strength-enhanced paper product.

15. The method according to any one of claims 11 to 14, wherein: i. Adding the cationic GPAM composition to a cellulose fiber suspension at the wet end of a papermaking facility; ii. The cationic GPAM composition is added in an amount of 0.02 dry weight% to 10 dry weight% based on the dry weight of the cellulose fibers; iii. Adding the cationic GPAM composition before, during, and / or after forming the paper product; iv. After forming the paper product, adding the cationic GPAM composition to one or more surfaces of the paper product; v. The cationic GPAM composition provides paper strength enhancement to the paper product, and the paper strength is determined by the STFI test; vi. The cationic GPAM composition provides paper strength enhancement to the paper product, and the paper strength is determined by the burst strength test; vii. The paper product includes one or more of hand sheets, board-based products, beverage or food carriers, paper boxes, tissue papers and towel-grade paper products, paper bags, liners for corrugated boxes, diapers, sanitary napkins, training pants, pantiliners, incontinence briefs, tampons, urine pads, trash can liners, coffee filter bags, air filtration materials, drying pads, floor cleaning pads, napkins, and wrapping papers; viii. The paper product includes a cellulose paperboard web containing cellulose fibers; ix. The cationic GPAM composition reduces the drainage time of the treated sample compared to the drainage time without using the cationic GPAM composition; x. The cationic GPAM composition increases the drainage rate of the treated sample compared to the drainage rate without using the cationic GPAM composition, resulting in an increase in the paper production rate; xi. The cationic GPAM composition improves the drying energy savings of the papermaking process; xii. The cationic GPAM composition reduces the total solids content of the treated sample compared to the total solids content without using the cationic GPAM composition; xiii. The cationic GPAM composition reduces the total solids content of the white water treated from trays or silos after paper forming compared to the total solids content without using the cationic GPAM composition; and / or xiv. A combination of any two or more of (i)-(xiii).

16. The method according to any one of claims 11 to 14, wherein the one or more cationic GPAM compositions comprise GPAM, wherein: i. The first base polymer and the second base polymer comprise a copolymer of acrylamide or methacrylamide and one or more cationic monomers; ii. The first base polymer and / or the second base polymer comprise(s) a copolymer of (a) acrylamide and / or methacrylamide and acryloyloxyethyl trimethyl ammonium chloride and / or (b) dimethyldiallylammonium chloride (DADMAC) monomers; iii. The first base polymer or the second base polymer comprises a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; iv. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; v. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers, and the glyoxal:base polymer ratio for the glyoxalation reaction ranges from 10:90 to 90:10; vi. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC); the molecular weight of the first base polymer is 25 kDa or less; vii. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; the molecular weight of the first base polymer is 25 kDa or less, and the molecular weight of the second base polymer is at least 50 kDa; and the glyoxal:base polymer ratio for the glyoxalation reaction for glyoxalating the first base polymer and / or the second base polymer ranges from 10:90 to 90:10; viii. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; the molecular weight of the first base polymer is 25 kDa or less; the glyoxal:base polymer ratio for the glyoxalation reaction for the first base polymer and / or the second base polymer ranges from 10:90 to 90:10; and the weight ratio of the first base polymer to the second base polymer ranges from 10:90 to 90:10; or ix. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC); the molecular weight of the first base polymer is 25 kDa or less, and the molecular weight of the second base polymer is at least 50 kDa; the glyoxal:base polymer ratio for the glyoxalation reaction for the first base polymer and / or the second base polymer ranges from 10:90 to 90:10; and the weight ratio of the first base polymer to the second base polymer ranges from 10:90 to 90:10, and the cationic GPAM content ranges from 5% to 7%.

17. A method for preparing a cationic GPAM composition according to any one of claims 1 to 7, the method comprising: i. Glyoxalating the first base polymer in a first glyoxalation reaction comprising glyoxal to produce a first glyoxalated base polymer; ii. Glyoxalating the second base polymer in a second glyoxalation reaction comprising glyoxal to produce a second glyoxalated base polymer; and iii. Combining the first glyoxalated base polymer and the second glyoxalated base polymer to produce the cationic GPAM composition; where steps (i) and (ii) can be carried out in any order or simultaneously.

18. A method for preparing a cationic GPAM composition according to any one of claims 1 to 7, the method comprising: i. Combining the first base polymer and the second base polymer; and ii. Glyoxalating the combination of the first base polymer and the second base polymer in a glyoxalation reaction comprising glyoxal to produce the cationic GPAM composition.

19. A method for preparing a cationic GPAM composition according to any one of claims 1 to 7, the method comprising: i. Glyoxalating the first base polymer in a glyoxalation reaction comprising glyoxal to produce a first glyoxalated base polymer; and ii. Adding the second base polymer and additional glyoxal to the glyoxalation reaction to produce the cationic GPAM composition.

20. A method for preparing a cationic GPAM composition according to any one of claims 1 to 7, the method comprising: i. Glyoxalating the second base polymer in a glyoxalation reaction comprising glyoxal to produce a second glyoxalated base polymer; and ii. Add the first base polymer and additional glyoxal to the glyoxalation reaction to produce the cationic GPAM composition.

21. A method for preparing a cationic GPAM composition according to any one of claims 1 to 7, the method comprising: i. Glyoxalate the first base polymer in a first glyoxalation reaction containing glyoxal to produce a first glyoxalated base polymer; and ii. Glyoxalate the second base polymer and the first glyoxalated base polymer in a second glyoxalation reaction containing glyoxal to produce the cationic GPAM composition.

22. A method for preparing a cationic GPAM composition as claimed in any one of claims 1 to 7, the method comprising: i. Glyoxalate the second base polymer in a second glyoxalation reaction containing glyoxal to produce a second glyoxalated base polymer; and ii. Glyoxalate the first base polymer and the second glyoxalated base polymer in a first glyoxalation reaction containing glyoxal to produce the cationic GPAM composition.

23. A cationic GPAM composition, the cationic GPAM composition being prepared according to any one of the methods as claimed in claims 17 to 22.

24. The cationic GPAM composition as claimed in claim 23, wherein: i. The first base polymer and the second base polymer comprise a copolymer of acrylamide or methacrylamide and one or more cationic monomers; ii. The first base polymer and / or the second base polymer comprise a copolymer of (a) acrylamide and / or methacrylamide and acryloyloxyethyltrimethylammonium chloride and / or (b) dimethyldiallylammonium chloride (DADMAC) monomers; iii. The first base polymer or the second base polymer comprises a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; iv. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; v. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC), and the glyoxal:base polymer ratio for the glyoxalation reaction ranges from 10:90 to 90:10; vi. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; the molecular weight of the first base polymer is 25 kDa or less, and the molecular weight of the second base polymer is at least 50 kDa; vii. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; the molecular weight of the first base polymer is 25 kDa or less, and the molecular weight of the second base polymer is at least 50 kDa; and the glyoxal:base polymer ratio for the glyoxalation reaction used to glyoxalate the first base polymer and / or the second base polymer ranges from 10:90 to 90:10; viii. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; the molecular weight of the first base polymer is 25 kDa or less, and the molecular weight of the second base polymer is at least 50 kDa; the range of the glyoxal:base polymer ratio for the glyoxalation reaction of the first base polymer and / or the second base polymer is from 10:90 to 90:10; and the weight ratio of the first base polymer to the second base polymer ranges from 10:90 to 90:10; or ix. The first base polymer and the second base polymer comprise a copolymer of acrylamide and dimethyldiallylammonium chloride (DADMAC) monomers; the molecular weight of the first base polymer is 25 kDa or less, and the molecular weight of the second base polymer is at least 50 kDa; the range of the glyoxal:base polymer ratio for the glyoxalation reaction of the first base polymer and / or the second base polymer is from 10:90 to 90:10; and the weight ratio of the first base polymer to the second base polymer ranges from 10:90 to 90:10, and the range of the cationic GPAM content is from 5% to 7%.

25. A composition comprising one or more cationic GPAM compositions, wherein each of the one or more cationic GPAM compositions is prepared according to any one or a combination thereof of the methods as claimed in claims 17 to 22.

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