Methods for producing cationic polysaccharides

Abstract

Cationic polysaccharides and methods for producing cationic polysaccharides, and compositions that include cationic polysaccharides, which may be used as a polyelectrolyte, a flocculant, etc. The methods may include contacting a polysaccharide and a haloacyl halide to produce a haloacylated polysaccharide, and contacting the haloacylated polysaccharide and the amine to produce the cationic polysaccharide. The methods may include forming one or more suspensions in which the polysaccharide is dispersed.

Description

METHODS FOR PRODUCING CATIONIC POLYSACCHARIDESCross-reference to Related Applications

[0001] This application claims priority to Finnish Patent Application No. 20246441, filed December 10, 2024, and U.S. Provisional Patent Application No. 63 / 713,420, filed October 29, 2024, which are incorporated by reference herein.Background

[0002] Cationic polysaccharides are useful in a number of processes, compositions, etc. (e.g., WO2023287684). For example, cationic polysaccharides or compositions that include cationic polysaccharides may be used as polyelectrolytes, flocculants, etc.

[0003] There remains a need for cationic polysaccharides and methods for producing cationic polysaccharides, such as betainate substituted starches, celluloses, dextrans, glycogens, pullulans, etc. There also remains a need for cationic polysaccharides that are hydrolysable, including those that are hydrolysable and capable of maintaining cationicity for a time effective to serve one or more purposes or roles, such as to serve as a flocculant. There also remains a need for cationic polysaccharides that are biodegradable, including those that biodegrade into one or more environmentally benign decomposition products.Brief Summary

[0004] Provided herein are cationic polysaccharides, methods of producing cationic polysaccharides, and compositions that address one or more of the foregoing needs.

[0005] In one aspect, methods for producing cationic polysaccharides are provided. In some embodiments, the methods include contacting a polysaccharide, a haloacyl halide, and an amine, such as a tertiary amine, to produce a cationic polysaccharide. In some embodiments, the methods include contacting a polysaccharide, a haloacyl halide, an amine, such as a primary or secondary amine, and a quaternizing agent to produce a cationic polysaccharide. The contacting of the polysaccharide, the haloacyl halide, and the amine may include contacting the polysaccharide and the haloacyl halide to produce a haloacylated polysaccharide; and contacting the haloacylated polysaccharide and the amine (or the amine and the quaternizing agent) to produce the cationic polysaccharide.

[0006] In some embodiments, the polysaccharide does not include or consist of an a-1,3 -glucan, such as a- 1,3 -glucan.

[0007] In another aspect, cationic polysaccharides and compositions that include cationic polysaccharides are provided. The cationic polysaccharides or the compositions that include the cationic polysaccharides may be used as a flocculant or a polyelectrolyte.

[0008] Additional aspects will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the aspects described herein. The advantages described herein may be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive.Detailed Description

[0009] Provided herein are methods for producing cationic polysaccharides.

[0010] The methods generally may include (i) contacting a polysaccharide, a haloacyl halide, and an amine, such as a tertiary amine, to produce a cationic polysaccharide; or (ii) contacting a polysaccharide, a haloacyl halide, an amine, such as a primary or a secondary amine, and a quaternizing agent to produce a cationic polysaccharide. The polysaccharide used as a starting material, i.e., the polysaccharide contacted with a haloacyl halide, may not include or consist of an a-glucan, such as a-l,3-glucan.

[0011] The contacting of the polysaccharide, the haloacyl halide, and the amine (or the amine and the quatemizing agent) may be achieved using any known technique and any known apparatuses. The starting materials also may be contacted in any order or in any manner. Any combination of temperature and pressure may be used to effect any of the chemical reactions among the starting materials.

[0012] The contacting of the polysaccharide, the haloacyl halide, and the amine may include contacting the polysaccharide and the haloacyl halide to produce a haloacylated polysaccharide; and contacting the haloacylated polysaccharide and the amine (or the amine and the quatemizing agent) to produce the cationic polysaccharide.

[0013] Generally, a polysaccharide may be contacted with any amount of a haloacyl halide. Similarly, a haloacylated polysaccharide may be contacted with any amount of an amine (or amine and quatemizing agent). In some embodiments, a mole ratio of the polysaccharide to the haloacyl halide is about 1:1 to about 1:5, about 1:1 to about 1:4, about 1:1 to about 1:3, about 1:1.5 to about 1:2.5, or about 1:2. When “a mole ratio” is defined herein, the mole ratio defines, by mole, the relative amounts of the indicated reagents that are contacted. In some embodiments, a mole ratio of the haloacylated polysaccharide to theamine is about 1:10 to about 1:0.1, about 1:8 to about 1:0.1, about 1:6 to about 1:0.1, about 1:4 to about 1:0.1, about 1:2 to about 1:0.1, about 1:1 to about 1:0.1, about 1:0.9 to about 1:0.1, about 1:0.8 to about 1:0.2, about 1:0.7 to about 1:0.03, about 1:0.6 to about 1:0.4, or about 1:0.5.

[0014] A haloacylated polysaccharide generally may have any degree of substitution, and the degree of substitution may be adjusted in one or more ways, such as by adjusting the mole ratios of reactants. In some embodiments, a degree of substitution (i.e., degree of haloacylation, as determined by13C NMR) of the haloacylated polysaccharide is about 0.1 to about 3, about 0.5 to about 3, about 1 to about 3, about 1.5 to about 3, about 2 to about 3, about 0.1 to about 2.5, about 0.1 to about 2, about 0.1 to about 1.5, about 0.5 to about 1.5, about 0.5 to about 1. The phrase "degree of substitution”, as used herein, refers to the number of substituents (in this instance, haloacyl groups) per cyclic moiety of the product or intermediate product (in this instance, haloacylated polysaccharide), as determined by13C NMR.

[0015] The methods described herein may include forming one or more suspensions that include one or more starting materials, one or more intermediate products, one or more products, or a combination thereof dispersed in a liquid.

[0016] The methods described herein may include forming one or more homogeneous mixtures that include one or more starting materials, one or more intermediate products, one or more products, or a combination thereof. The homogeneous mixtures may include solutions.

[0017] In some embodiments, the methods include contacting the polysaccharide and a first liquid to form a first mixture, which may be a suspension. As used herein, the term “suspension” refers to a mixture that includes a liquid in which an insoluble or partially soluble material is dispersed evenly or unevenly. When a first mixture is formed, the contacting of the polysaccharide and the haloacyl halide may include disposing the haloacyl halide in the first mixture.

[0018] The first liquid of the first mixture may be a liquid in which the polysaccharide is insoluble or partially soluble. The first liquid of the first mixture may be a liquid in which the polysaccharide is insoluble or partially soluble, and the haloacylated polysaccharide is soluble. As used herein, a material is “soluble” in a liquid when the material has a solubility in the liquid of at least 1 g per 100 mL at room temperature and pressure, or at the temperature and pressure at which a chemical reaction is performed. As used herein, a material is “insoluble” in a liquid when the material has a solubility in theliquid of 0.1 g or less per 100 mL at room temperature and pressure, or at the temperature and pressure at which a chemical reaction is performed. As used herein, a material is "‘partially soluble’’ in a liquid when the material has a solubility in the liquid that is greater than 0.1 g and less than 1 g per 100 mL at room temperature and pressure, or at the temperature and pressure at which a chemical reaction is performed.

[0019] The first liquid may include any suitable liquid, such as an organic liquid, particularly a polar organic liquid. The polar organic liquid may include dimethylformamide.

[0020] In some embodiments, the methods include isolating the haloacylated polysaccharide from the first mixture. The isolating of the haloacylated polysaccharide may be achieved using any known technique and apparatus. For example, the isolating of the haloacylated polysaccharide from the first mixture may include precipitating and optionally washing the haloacylated polysaccharide, such as with one or more liquids, such as water or a short chain alcohol (e.g., methanol or ethanol).

[0021] In some embodiments, the methods include disposing the haloacylated polysaccharide in a second liquid to form a second mixture. The second mixture may be a homogeneous mixture. When a second mixture is formed, the contacting of the haloacylated polysaccharide and the amine (or the amine and the quatemizing agent) may include disposing the amine (or the amine and the quatemizing agent) in the second mixture.

[0022] The second liquid of the second mixture may be a solvent in which the haloacylated polysaccharide, the amine (or the amine and the quatemizing agent), the cationic polysaccharide, or a combination thereof is soluble. Generally, the second liquid may include any suitable liquid. In some embodiments, the second liquid includes an organic liquid, such as a polar organic liquid. The second liquid may include acetonitrile, dimethyl sulfoxide, or a combination thereof.

[0023] The methods provided herein, at least in part, may be performed in anhydrous conditions. As used herein, the phrase “anhydrous” refers to the absence of water, or an amount of water that is effective to avoid converting more than 5 mole %, more than 1 mole %, or more than 0.1 mole % of any starting material, intermediate product, product, or a combination thereof to undesired side products.

[0024] The methods provided herein, at least in part, may be performed in conditions effective to prevent, or reduce the likelihood of, hydrolysis of the cationic polysaccharide. Not wishing to be bound by any particular theory, it is believed that a hydrolysis of the cationic polysaccharide is more likely to occur when the cationic polysaccharide is disposed in water, particularly at a pH of at least 6.

[0025] In some embodiments, the first liquid, the second liquid, or both the first liquid and the second liquid do not include water. In some embodiments, water is present in the first mixture, the second mixture, or the first mixture and the second mixture at an amount that is effective to avoid producing an undesired amount of side products, such as side products resulting from a reaction between water and the haloacyl halide. For example, water may be present in the first mixture and / or the second mixture at an amount not exceeding 5 wt%, 3 wt%, 1 wt%, 0.5 wt%, or 0.1 wt%, based on the weight of the first mixture and / or second mixture, respectively.Haloacyl Halide

[0026] Generally, any haloacyl halide may be used in the methods provided herein.

[0027] In some embodiments, the haloacyl halide includes a compound of the following formula:

[0028] wherein R is a divalent Ci-Ce hydrocarbyl, such as a Ci-Ce alky lene, a Ci-Cs alky lene, a C1-C4 alkylene, a C1-C3 alkylene, a C1-C2 alkylene, or a Ci alkylene; and wherein X1and X2are independently selected from a halogen. X1and X2may be identical or different. In some embodiments, X1and X2are Cl.

[0029] In some embodiments, the haloacyl halide includes a haloacetyl halide. The haloacetyl halide may include chloroacetyl chloride.Amine

[0030] Generally, any amine may be used in the methods described herein. In some embodiments, the amine is a tertiary (3°) amine, a secondary (2°) amine, or a primary (1°) amine. When a secondary or primary amine is used in the methods described herein, a quatemizing agent may be used. The quatemizing agent may include any of those known in the art, such as an alkyl halide.

[0031] In some embodiments, the amine is a compound of the following formula:

[0032] wherein R1, R2, and R3are independently selected from hydrogen or a C1-C5 hydrocarbyl, such as a C1-C5 alkyl, a C1-C4 alkyl, a C1-C3 alkyl, a C1-C2 alkyl, or a C1 alkyl(i.e., methyl). In some embodiments, one, two, or three of R1, R2, and R3is independently selected from a C1-C5 hydrocarbyl. When a quatemizing agent is used in the methods described herein, the quaternizing agent may be selected from an agent of formula R1X, R2X, R3X, or a combination thereof, wherein R1, R2, R3are as defined above, and X is a halogen, such as Cl.Cationic Polysaccharides

[0033] Also provided herein are cationic polysaccharides, including cationic polysaccharides produced according to the methods provided herein. Compositions that include any of the cationic polysaccharide also are provided. The cationic polysaccharides or the compositions provided herein may be useful in a number of applications; for example, the cationic polysaccharides and compositions may be useful as flocculants or polyelectrolytes.

[0034] The cationic polysaccharides generally may have any molecular weight. The molecular weight may be chosen based on the intended use of the cationic polysaccharide. In some embodiments, the cationic polysaccharide has a molecular weight (weight average molecular weight, Mw) of about 200 g / mol to about 200,000 g / mol. about 200 g / mol to about 150,000 g / mol, about 200 g / mol to about 100,000 g / mol, about 200 g / mol to about 75,000 g / mol, about 200 g / mol to about 50,000 g / mol, about 200 g / mol to about 40,000 g / mol, about 200 g / mol to about 30,000 g / mol, about 200 g / mol to about 20,000 g / mol, about 200 g / mol to about 15,000 g / mol, about 200 g / mol to about 10,000 g / mol, about 200 g / mol to about 5,000 g / mol, or about 200 g / mol to about 1,000 g / mol.

[0035] In some embodiments, the (i) cationic polysaccharides and / or (ii) one or more products produced by a hydrolysis reaction of the cationic polysaccharide are biodegradable. The term “biodegradable” is used herein in a manner that is consistent with its common and ordinary meaning. The cationic polysaccharides may be biodegradable within 10 years, within 5 years, or within 1 year of exposure to an environment in which biodegradation is possible. The cationic polysaccharides may be broken down, via biodegradation or otherwise, into environmentally inert products.

[0036] The phrases “Ci-Ct. hydrocarbyl,” “C2-C4 hydrocarbyl.” and the like, as used herein, generally refer to aliphatic, aryl, or arylalkyl groups containing 1 to 6 carbon atoms, or 2 to 4 carbon atoms, respectively, which may be monovalent or multivalent, as noted herein, and including any substituted derivatives thereof. Therefore, for example, the alkyl groups noted below may be alkylene groups, the cycloalkyl groups may be cycloalkylene groups, etc.

[0037] Examples of aliphatic groups, in each instance, include, but are not limited to, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an alkadienyl group, a cyclic group, and the like, and includes all substituted, unsubstituted, branched, and linear analogs or derivatives thereof, in each instance having 1 to about 6 carbon atoms, 2 to 4 carbon atoms, etc. Examples of alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, isobutyl, pentyl, hexyl, isohexyl, etc. Cycloalkyl moieties may be monocyclic or multi cyclic, and examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc. Additional examples of alkyl moieties have linear, branched and / or cyclic portions (e.g., 1-ethyl-4-methyl-cyclohexyl). Representative alkenyl moieties include vinyl, allyl. 1-butenyl, 2-butenyl. isobutylenyl, 1-pentenyl, 2-pentenyl, 3-methyl-l-butenyl, 2-methyl-2-butenyl, 2,3-dimethyl-2-butenyl, 1 -hexenyl, 2-hexenyl, 3-hexenyl, 1 -heptenyl, 2-heptenyl, 3-heptenyl, 1 -octenyl, 2 -octenyl, 3-octenyl, 1-nonenyl, 2-nonenyl, 3-nonenyl, 1 -decenyl, 2-decenyl and 3-decenyl. Representative alkynyl moieties include acetylenyl, propynyl, 1-butynyl, 2-butynyl, 1 -pentynyl, 2-pentynyl, 3-methyl-l-butynyl, 4-pentynyl, 1 -hexynyl, 2-hexynyl, 5-hexynyl, etc. Examples of aryl or arylalkyl moieties include, but are not limited to, anthracenyl, azulenyl, biphenyl, fluorenyl, indan, indenyl, naphthyl, phenanthrenyl, phenyl, 1,2,3,4-tetrahydro-naphthalene, tolyl, xylyl, mesityl, benzyd, and the like, including any heteroatom substituted derivative thereof.

[0038] Unless otherwise indicated, the term “substituted,"’ when used to describe a chemical structure or moiety, refers to a derivative of that structure or moiety wherein (i) a multi-valent non-carbon atom (e.g., oxygen, nitrogen, sulfur, phosphorus, etc.) is bonded to one or more carbon atoms of the chemical structure or moiety' (e.g., a “substituted” Ca hydrocarbyl may include, but is not limited to, diethyl ether moiety, an ethyl acetate moiety, a methoxylmethyl acetate moiety, a methyl propionate moiety, an N,N-dimethylacetamide moiety, a butoxy moiety, etc., and a "‘substituted” aryl C12 hydrocarbyl may include, but is not limited to, an oxy dibenzene moiety, a benzophenone moiety, etc.) and / or (ii) one or more of its hydrogen atoms (e.g., chlorobenzene may be characterized generally as an ary l Ce hydrocarbyl “substituted” with a chlorine atom) is substituted with a chemical moiety or functional group such as alcohol, alkoxy, alkanoyloxy, alkoxy carbonyl, alkenyl, alkyl (e.g., methyl, ethyl, propyl, t-butyl), alkynyl, alkylcarbonyl oxy (-OC(O)alkyl), amide (-C(O)NH-alkyl- or -alkylNHC(O)alkyl). tertiary amine (such as alkylamino, arylamino, arylalkylamino), aryl, aryloxy, azo, carbamoyl (-NHC(O)O-alkyl- or -OC(O)NH-alkyl), carbamyl (e.g.. CONH2, as well as CONH-alkyl, CONH-aryl. and CONH-arylalkyl). carboxyl, carboxylic acid, cyano, ester, ether (e.g., methoxy, ethoxy), halo, haloalkyl (e.g., -CCl3, -CF3, -C(CF3)3), heteroalkyl, isocyanate, isothiocyanate, nitrile, nitro, oxo, phosphodiester, sulfide, sulfonamido (e.g, SO2NH2), sulfone, sulfonyl (including alkylsulfonyl, arylsulfonyl and arylalkylsulfonyl), sulfoxide, thiol (e.g., sulfhydryl, thioether) or urea (-NHCONH-alkyl-).

[0039] All referenced publications are incorporated herein by reference in their entirety. Furthermore, where a definition or use of a term in a reference, which is incorporated by reference herein, is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.

[0040] While certain aspects of conventional technologies have been discussed to facilitate disclosure of various embodiments, applicants in no way disclaim these technical aspects, and it is contemplated that the present disclosure may encompass one or more of the conventional technical aspects discussed herein.

[0041] The present disclosure may address one or more of the problems and deficiencies of known methods and processes. However, it is contemplated that various embodiments may prove useful in addressing other problems and deficiencies in a number of technical areas. Therefore, the present disclosure should not necessarily be construed as limited to addressing any of the particular problems or deficiencies discussed herein.

[0042] In this specification, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date, publicly available, known to the public, part of common general knowledge, or otherwise constitutes prior art under the applicable statutory provisions; or is known to be relevant to an attempt to solve any problem with which this specification is concerned.

[0043] In the descriptions provided herein, the terms ‘includes,’’ ‘is,” “containing,” “having,” and “comprises” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to.” When materials or methods are claimed or described in terms of “comprising” various steps or components, the materials or methods can also “consist essentially of’ or “consist of’ the various steps or components, unless stated otherwise.

[0044] The terms “a,” “an,” and “the” are intended to include plural alternatives, e.g., at least one. For instance, the disclosure of “an amine”, “a liquid”, and the like, is meant to encompass one, or mixtures or combinations of more than one amine, liquid, and the like, unless otherwise specified.

[0045] When two or more elements, such as two or more substituents, are selected “independently” from a recited listing of options, the two or more substituents may be the same or different; for example, when A and B are selected from hydrogen and a C1-C2 alkyl, (i) A and B may be hydrogen, (ii) A may be hydrogen, and B may be a Ci alkyl, (iii) A may be a Ci alkyl, and B may be a C2 alkyl, etc.

[0046] Various numerical ranges may be disclosed herein. When Applicant discloses or claims a range of any type, Applicant’s intent is to disclose or claim individually each possible number that such a range could reasonably encompass, including end points of the range as well as any sub-ranges and combinations of sub-ranges encompassed therein, unless otherwise specified. Moreover, all numerical end points of ranges disclosed herein are approximate. As a representative example, Applicant discloses, in some embodiments, a degree of substitution is about 1.5 to about 2.5. This range should be interpreted as encompassing about 1.5 and about 2.5 and further encompasses “about” each of 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, and 3.4, including any ranges and sub-ranges between any of these values.

[0047] As used herein, the term “about” means plus or minus 10 % of the numerical value of the number with which it is being used.LISTING OF EMBODIMENTS

[0048] The following is a non-limiting listing of embodiments of the disclosure.

[0049] Embodiment 1. A method for producing a cationic polysaccharide, the method comprising, consisting essentially of, or consisting of -

[0050] contacting a polysaccharide, a haloacyl halide, and an amine (e.g., a tertiary amine) to produce a cationic polysaccharide; or

[0051] contacting a polysaccharide, a haloacyl halide, an amine (e.g., a primary or secondary amine), and a quatemizing agent to produce a cationic polysaccharide;

[0052] wherein the polysaccharide does not comprise or consist of an a-glucan, such as a- 1,3 -glucan.

[0053] Embodiment 2. The method of Embodiment 1, wherein the contacting of the polysaccharide, the haloacyl halide, and the amine (or the amine and the quatemizing agent) comprises, consists essentially of, or consists of -

[0054] contacting the polysaccharide and the haloacyl halide to produce a haloacylated polysaccharide; and

[0055] contacting the haloacylated polysaccharide and the amine (or the amine and the quaternizing agent) to produce the cationic polysaccharide.

[0056] Embodiment 3. The method of Embodiment 2, further comprising, consisting essentially of, or consisting of -

[0057] contacting the polysaccharide and a first liquid to form a first mixture, which may be a suspension in which the polysaccharide is dispersed; and wherein the contacting of the polysaccharide and the haloacyl halide comprises, consists essentially of, or consists of disposing the haloacyl halide in the first mixture.

[0058] Embodiment 4. The method of any of the preceding Embodiments, wherein the polysaccharide is (i) insoluble, or (ii) partially soluble in the first liquid.

[0059] Embodiment 5. The method of any of the preceding Embodiments, wherein the first liquid comprises, consists essentially of, or consists of an organic liquid, such as a polar organic liquid.

[0060] Embodiment 6. The method of any of the preceding Embodiments, wherein the organic liquid comprises, consists essentially of, or consists of dimethylformamide (DMF).

[0061] Embodiment 7. The method of any of the preceding Embodiments, wherein the haloacylated polysaccharide is soluble in the first liquid.

[0062] Embodiment 8. The method of any of the preceding Embodiments, further comprising isolating the haloacylated polysaccharide from the first mixture.

[0063] Embodiment 9. The method of any of the preceding Embodiments, wherein the isolating of the haloacylated polysaccharide from the first mixture comprises precipitating and optionally washing the haloacylated polysaccharide, such as with one or more liquids, such as water or a short chain alcohol (e.g., methanol or ethanol).

[0064] Embodiment 10. The method of any of the preceding Embodiments, further comprising, consisting essentially of, or consisting of disposing the haloacylated polysaccharide in a second liquid to form a second mixture, which may be a homogeneous mixture; wherein the contacting of the contacting the haloacylated polysaccharide and the amine (or the amine and the quaternizing agent) comprises, consists essentially of, or consists of disposing the amine (or the amine and the quaternizing agent) in the second liquid.

[0065] Embodiment 11. The method of any of the preceding Embodiments, wherein the second liquid is a solvent.

[0066] Embodiment 12. The method of any of the preceding Embodiments, wherein the second liquid comprises, consists essentially of, or consists of an organic liquid, such as a polar organic liquid.

[0067] Embodiment 13. The method of any of the preceding Embodiments, wherein the organic liquid comprises, consists essentially of, or consists of acetonitrile, dimethyl sulfoxide, or a combination thereof.

[0068] Embodiment 14. The method of any of the preceding Embodiments, wherein the first liquid and / or the second liquid does not include water.

[0069] Embodiment 15. The method of any of the preceding Embodiments, wherein water is present in the first liquid and / or the second liquid at an amount that is effective to avoid producing an undesired amount of side products, such as side products resulting from a reaction between the water and the haloacyl halide.

[0070] Embodiment 16. The method of any of the preceding Embodiments, wherein the contacting of the polysaccharide, the haloacyl halide, and the amine (or the amine and the quatemizing agent) are performed in conditions effective to prevent, or reduce the likelihood of, hydrolysis of an intermediate product and / or the cationic polysaccharide.

[0071] Embodiment 17. The method of any of the preceding Embodiments, wherein the contacting of the polysaccharide, the haloacyl halide, and the amine (or the amine and the quatemizing agent) are performed in anhydrous conditions.Haloacyl Halide

[0072] Embodiment 18. The method of any of the preceding Embodiments, wherein the haloacyl halide.

[0073] Embodiment 19. The method of any of the preceding Embodiments, wherein the haloacyl halide comprises, consists essentially of, or consists of a compound of the following formula:

[0074] wherein R is a divalent C1-C6 hydrocarbyl, such as a C1-C6 alkylene, a C1-C5 alkylene, a C1-C4 alkylene, a C1-C3 alkylene, a C1-C2 alkylene, or a C1 alkylene; and

[0075] wherein X1and X2are independently selected from a halogen.

[0076] Embodiment 20. The method of any of the preceding Embodiments, wherein X1and X2are identical.

[0077] Embodiment 21. The method of any of the preceding Embodiments, wherein the haloacyl halide comprises, consists essentially of, or consists of a haloacetyl halide.

[0078] Embodiment 22. The method of any of the preceding Embodiments, wherein the haloacetyl halide comprises, consists essentially of, or consists of chloroacetyl chloride. Amine

[0079] Embodiment 23. The method of any of the preceding Embodiments, wherein the amine is a tertiary (3°) amine, a secondary (2°) amine, or a primary (1°) amine.

[0080] Embodiment 24 The method of any of the preceding Embodiments, wherein the amine is a compound of the following formula:

[0081] wherein R1, R2, and R3are independently selected from hydrogen or a C1-C5 hydrocarbyl, such as a C1-C5 alkyl, a C1-C4 alkyl, a C1-C3 alkyl, a C1-C2 alkyl, or a Ci alkyl (i.e., methyl).Characteristics of Product

[0082] Embodiment 25. The method of any of tire preceding Embodiments, wherein the cationic polysaccharide is biodegradable.

[0083] Embodiment 26. The method of any of the preceding Embodiments, wherein one or more products produced by a hydrolysis reaction of the cationic polysaccharide are biodegradable.

[0084] Embodiment 27. The method of any of the preceding Embodiments, wherein a hydrolysis of the cationic polysaccharide occurs when the cationic polysaccharide is disposed in water, such as water having a pH of at least 6.Quaternizing Agent

[0085] Embodiment 28. The method of any of the preceding Embodiments, wherein the quaternizing agent comprises, consists essentially of, or consists of an alkyl halide, such as a Ci-C5 alkyl halide.Polysaccharide

[0086] Embodiment 29. The method of any of the preceding Embodiments, wherein the polysaccharide is selected from starch, cellulose, dextran, glycogen, pullulan, or a combination thereof.

[0087] Embodiment 30. A cationic polysaccharide produced according to the method of any of the preceding Embodiments.

[0088] Embodiment 31. A composition comprising, consisting essentially of, or consisting of the cationic polysaccharide of Embodiment 30.

[0089] Embodiment 32. The cationic polysaccharide or the composition of any of the preceding Embodiments, wherein the cationic polysaccharide or the composition is a flocculant or a polyelectrolyte.

[0090] Embodiment 33. The method, the cationic polysaccharide, or the composition of any of the preceding Embodiments, wherein the cationic polysaccharide has a degree of substitution (i.e., number of cationic substituents per cyclic moiety cationic polysaccharide) of about 0.1 to about 3, about 0.5 to about 3, about 1 to about 3, about 1.5 to about 3, about 2 to about 3, about 0.1 to about 2.5, about 0.1 to about 2, about 0.1 to about 1.5, about 0.5 to about 1.5, or about 0.5 to about 1.

[0091] Embodiment 34. The method, the cationic polysaccharide, or the composition of any of the preceding Embodiments, wherein the cationic polysaccharide has a molecular weight (weight average molecular weight, Mw) of about 200 g / mol to about 200,000 g / mol, about 200 g / mol to about 150,000 g / mol, about 200 g / mol to about 100,000 g / mol, about 200 g / mol to about 75,000 g / mol, about 200 g / mol to about 50,000 g / mol, about 200 g / mol to about 40,000 g / mol, about 200 g / mol to about 30,000 g / mol, about 200 g / mol to about 20,000 g / mol, about 200 g / mol to about 15,000 g / mol, about 200 g / mol to about 10,000 g / mol, about 200 g / mol to about 5,000 g / mol, or about 200 g / mol to about 1,000 g / mol.

Claims

Claims - 1. A method for producing a cationic polysaccharide, the method comprising:contacting a polysaccharide and a haloacyl halide to produce a haloacylated polysaccharide; andcontacting the haloacylated polysaccharide and an amine to produce the cationic polysaccharide;wherein the contacting of the polysaccharide and the haloacyl halide comprises - contacting the polysaccharide and a first liquid to form a first mixture, wherein the polysaccharide is insoluble, or partially soluble in the first liquid, and the first mixture is a suspension in which the polysaccharide is dispersed, anddisposing the haloacyl halide in the first mixture; andwherein the polysaccharide does not include an a-glucan.

2. The method of claim 1, wherein the first liquid comprises a polar organic liquid.

3. The method of claim 2, wherein the polar organic liquid comprises dimethylformamide (DMF).

4. The method of claim 1, wherein the haloacylated polysaccharide is soluble in the first liquid.

5. The method of claim 1, further comprising:disposing the haloacylated polysaccharide in a second liquid to form a second mixture;wherein the contacting of the contacting the haloacylated polysaccharide and the amine comprises disposing the amine in the second liquid.

6. The method of claim 5, wherein the second liquid is a solvent in which the haloacylated polysaccharide is soluble, and wherein the second mixture is a homogeneous mixture.

7. The method of claim 5, wherein the second liquid comprises a polar organic liquid.

8. The method of claim 7, wherein the polar organic liquid comprises acetonitrile, dimethyl sulfoxide, or a combination thereof.

9. The method of claim 1, wherein (i) the contacting of the polysaccharide and the haloacyl halide, and (ii) the contacting of the haloacylated polysaccharide and the amine are performed in anhydrous conditions.

10. The method of claim 1, wherein the haloacyl halide comprises chloroacetyl chloride.

11. The method of claim 1, wherein the haloacyl halide comprises a compound of the following formula:wherein R is a divalent Ci-Ce hydrocarbyl; andwherein X1and X2are independently selected from a halogen.

12. The method of claim 1, wherein the amine is a tertiary (3°) amine.

13. The method of claim 1, wherein the cationic polysaccharide is biodegradable, or one or more products produced by a hydrolysis reaction of the cationic polysaccharide is biodegradable.

14. The method of claim 1, wherein the cationic polysaccharide has a degree of substitution of about 0.5 to about 3.

15. The method of claim 1, further comprising contacting the haloacylated polysaccharide and a quatemizing agent.

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