Methods of producing cationic esters of polysaccharides

Abstract

Cationic polysaccharides, methods of forming cationic polysaccharides, and methods of purification. Methods including contacting a polysaccharide and a vinyl betainate, a vinyl ester, or a combination thereof. The cationic polysaccharides may be used in a number of methods, including water purification.

Description

METHODS OF PRODUCING CATIONIC ESTERS OF POLYSACCHARIDESCross-reference to Related Applications

[0001] This application claims priority to Finnish Patent Application No. 20246445, filed December 10, 2024, and U. S. Provisional Patent Application No. 63 / 713,422, filed October 29, 2024, which are incorporated by reference herein.Background

[0002] Methods of purification, especially water purification, are important in a number of industries and applications. In methods of purification, cationic polymers may be used for one or more purposes, such as flocculation.

[0003] Due at least to their natural abundance and bio-compatibility, bio-based polymers, such as cellulose, starch, etc., can offer a suitable platform for preparing cationic polymers for methods of purification, especially water purification.

[0004] Preparation of cationic cellulose or starch derivatives, however, especially those with well-defined substitution patterns, can be challenging. For water soluble derivatives, homogeneous transformations are typically required.

[0005] There remains a need for methods, including robust, relatively simple, and / or efficient methods, of preparing cationic polysaccharide derivatives, such as cationic cellulose or starch derivatives, which are capable of achieving an intended purpose, such as effective flocculation, while maintaining suitable stability’, biodegradability, or a combination thereof. There also remains a need for methods of preparing cationic polysaccharide derivatives that avoid or reduce one or more unwanted side products, and rely in whole, or in part, on chemicals of biological origin, which can achieve or improve the biodegradability of one or more decomposition products. There also remains a need for new bio-based cationic polymers that may be used instead of petroleum based synthetic cationic polymers.Brief Summary

[0006] Provided herein are methods of preparing cationic polysaccharides, including methods that use bio-based polymers, such as cellulose, as starting materials.

[0007] In one aspect, methods for producing cationic polysaccharides are provided. In some embodiments, the methods include contacting (i) a polysaccharide, and (ii) a vinyl betainate, a vinyl ester, or a combination thereof to produce the cationic polysaccharide. The polysaccharide, in some embodiments, does not comprise or consist of an a-glucan, such asan a-l,3-glucan. The vinyl betainate, the vinyl ester, or the combination thereof may include at least one compound of the following formula:Anio

[0008] wherein R and R’ are independently selected from a C1-C12 hydrocarbyl. R may include at least one positively charged heteroatom. R’ may include at least one unsaturated bond, at least one electron withdrawing substituent, or a combination thereof.

[0009] In another aspect, cationic polysaccharides are provided. In some embodiments, the cationic polysaccharide has a structure that includes the following formula:

[0010] wherein Ra, Rb, and Rcare independently selected from hydrogen or a substituent of the following formula -

[0011] wherein at least one of Ra, Rb, and Rcis not hydrogen; and wherein R is a Ci-C12 hydrocarbyl that includes at least one positively charged heteroatom, and n is an integer from 10 to 100,000.

[0012] In another aspect, methods of purification are provided. In some embodiments, the methods include providing an amount of water; and contacting the water and a cationic polysaccharide described herein.

[0013] 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.Brief Description of the Drawings

[0014] FIG. 1A depicts a workflow diagram of embodiments of the methods described herein.

[0015] FIG. 1B depicts a test scale workflow of embodiments of the methods described herein.

[0016] FIG. 1C depicts an upscaling workflow of embodiments of the methods described herein.

[0017] FIG. 2 depicts kinetic data pertaining to the hydrolysis of an embodiment of a vinyl betaine ester in water (X - vinyl betainate; circles - betaine).Detailed Description

[0018] Provided herein are methods of producing cationic polysaccharides, and methods of purification.

[0019] In some embodiments, the methods of forming a cationic polysaccharide include contacting (i) a polysaccharide, and (ii) a vinyl betainate, a vinyl ester, or a combination thereof to produce the cationic polysaccharide. The polysaccharide, in some embodiments, does not comprise or consist of an a-glucan, such as an a-l,3-glucan. The polysaccharide generally may include any of those known in the art, including natural, artificial, or modified polysaccharides. Non-limiting examples of polysaccharides that may be used include starch, cellulose, dextran, glycogen, pullulan. or a combination thereof.

[0020] The contacting of the polysaccharide and the vinyl betainate, the vinyl ester, or the combination thereof 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, intermediate products, etc.

[0021] In some embodiments, the methods include pre-treating the polysaccharide prior to the contacting of the polysaccharide and the vinyl betainate, the vinyl ester, or the combination thereof. The pre-treating of the polysaccharide may include contacting the polysaccharide and a base, or any other agent that chemically modifies (e.g., via deprotonation, via protonation, etc.) a polysaccharide. Generally, any base may be used for pre-treating a polysaccharide. In some embodiments, the base includes NaOH. Any concentration of a base may be used. In some embodiments, the concentration of the base is about 0.001M to about 0.5 M, about 0.01 M to about 0.5 M, about 0.01 M to about 0.25 M, about 0.01 M to about 0.1 M. A polysaccharide also may be contacted with any amount,actual or relative, of a base. In some embodiments, the polysaccharide is contacted with about 1 mol% to about 30 mol%, about 1 mol% to 25 mol%, about 10 mol% to about 25 mol%, about 15 mol% to about 25 mol%, or about 20 mol% to about 25 mol% of the base, relative to the vinyl betainate, the vinyl ester, or the combination thereof.

[0022] The methods provided herein also may include washing the cationic polysaccharide. The washing of the cationic polysaccharide may include contacting the cationic polysaccharide and anon-nucleophilic liquid (e.g., solvent), such as acetone, toluene, dioxane, etc.

[0023] In some embodiments, the contacting of the polysaccharide and the vinyl betainate, the vinyl ester, or the combination thereof produces one or more side products. When one or more side products are produced, then the methods may also include collecting the one or more side products. The one or more side products may include acetaldehyde.

[0024] Generally, a polysaccharide may be contacted with any amount, actual or relative, of a vinyl betainate, vinyl ester, or a combination thereof. In some embodiments, the polysaccharide is contacted with about 1 to about 5. about 1 to about 4. about 1 to about 3, or about 2 to about 3 equivalents of the vinyl betainate, the vinyl ester, or the combination thereof per cyclic moiety of the polysaccharide.

[0025] A cationic 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 (z.e., as determined by 'H NMR) of the cationic polysaccharide is about 0.01 to about 3, about 0.01 to about 2.5, about 0.01 to about 2, about 0.01 to about 1.5, about 0.01 to about 1, about 0.01 to about 0.8, about 0.01 to about 0.6, about 0.03 to about 0.6, about 0.03 to about 0.55, about 0.03 to about 0.5, about 0.03 to about 0.45. about 0.03 to about 0.4, about 0.03 to about 0.35, about 0.03 to about 0.3, about 0.03 to about 0.25, about 0.03 to about 0.2, about 0.03 to about 0.15, or about 0.03 to about 0.1. The phrase “degree of substitution”, as used herein, refers to the number of substituents (in this instance, ester groups) per cyclic moiety of the product, as determined b

[0026] The contacting of (i) the polysaccharide and (ii) the vinyl betainate, the vinyl ester, or the combination thereof may occur, at least in part, in a liquid.

[0027] A polysaccharide and a cationic polysaccharide, independently, may be soluble, partially soluble, or insoluble in the liquid. As used herein, a material, such as a polysaccharide, 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 atwhich a chemical reaction is performed. As used herein, a material is "insoluble" in a liquid when the material has a solubility in the liquid 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. When a polysaccharide is soluble in a liquid, a mixture of the polysaccharide and the liquid may be a solution. When a polysaccharide is insoluble or partially soluble in a liquid, a mixture of the polysaccharide and the liquid may be a suspension in which the polysaccharide is evenly or unevenly dispersed.

[0028] When the contacting of a polysaccharide and a vinyl betainate and / or a vinyl ester occurs in a liquid, then the polysaccharide may be present at any concentration in the liquid, preferably a concentration that does not undesirably impact the reaction of the polysaccharide and the vinyl betainate and / or the vinyl ester. In some embodiments, a concentration of the polysaccharide in the liquid (prior to the contacting of the polysaccharide and the vinyl betainate, vinyl ester, or the combination thereof) is about 0.01 wt% to about 30 wt%, about 0.01 wt% to about 25 wt%, about 0.01 wt% to about 20 wt%, about 0.01 wt% to about 15 wt%, about 0.01 wt% to about 10 wt%, about 0.01 wt% to about 5 wt%, about 0.01 wt% to about 2.5 wt%, about 0.01 wt% to about 0.5 wt%, about 0.1 wt% to about 0.5 wt%, based on the total weight of the liquid and the polysaccharide.

[0029] When the liquid includes an ionic liquid in which the cationic polysaccharide is insoluble, then the methods may also include separating the cationic polysaccharide from the ionic liquid using any known technique.

[0030] In some embodiments, the liquid includes an ionic liquid. The ionic liquid may be a superbase ionic liquid, such as [mTBNH][0Ac], In some embodiments, the liquid includes water or an organic liquid, such as a polar organic liquid. It w as surprisingly discovered, as explained herein, that embodiments of the methods provided herein are successful when a polysaccharide, such as starch, is disposed in water, due at least in part to the fact that a possible hydrolytic side reaction of the reagents (e.g. vinyl betainate) with water does not undesirably interfere with the synthesis under proper reaction conditions. It was also surprisingly discovered, as explained herein, that the derivatization of cellulose can be conducted successfully under relatively mild conditions (e g., a temperature less than 100 °C) when the liquid is a superbase ionic liquid (e.g.. SB-IL. [mTBNH][OAc]), which can dissolve a polysaccharide, such as cellulose.

[0031] Generally, any vinyl betainate and / or other vinyl ester may be used in the methods described herein. In some embodiments, the vinyl betainate, the vinyl ester, or the combination thereof includes one or more compounds of the following formula:O©A■AmonA / R'© FT XT •

[0032] wherein R, independently, is a C1-C12 hydrocarbyl comprising at least one positively charged heteroatom; and wherein R’, independently, is a C1-C12 hydrocarbyl, optionally including at least one unsaturated bond, at least one electron withdrawing substituent, or a combination thereof, as described herein. The anion generally may be any anion that does not undesirably impact the methods described herein. In some embodiments, the anion is a halide, such as a chloride.

[0033] In some embodiments, R’ includes a double bond, a halo substituent (such as a fluoro- substituent), or a combination thereof. For example, R’ may include at least one trifluoromethyl moiety. As a further example, R’ may include at least one nitro substituent. R’, for instance, may include an aryl group substituted with at least one nitro substituent, such as a 4-nitrophenyl group. The positively charged heteroatom of R may be any known heteroatom. In some embodiments, the heteroatom is a nitrogen atom of an amine, such as a primary (1°), secondary (2°), or tertiary (3°) amine.

[0034] In some embodiments, R is of the following formula:

[0035] wherein R1is a divalent C1-C9 hydrocarbyl; wherein R2, R3, and R4are independently selected from hydrogen or a Ci-Ce hydrocarbyl, such as a a C1-C5 hydrocarbyl, a C1-C4 hydrocarbyl, a C1-C3 hydrocarbyl, a C1-C2 hydrocarbyl, or a Ci hydrocarbyl (e.g., a methy l); and wherein the total number of carbon atoms in R1, R2, R3, and R4is 12 or less.

[0036] In some embodiments, the vinyl betaine, the vinyl ester, or the combination thereof is selected from the following non-limiting listing of examples:

[0037] Although a chloride anion is depicted in these structures, each structure may include a different anion, such as a different halide, another inorganic anion, organic anion, etc.

[0038] The contacting of a polysaccharide and a vinyl betainate and / or vinyl ester generally may occur under any conditions. In some embodiments, the contacting of the polysaccharide and the vinyl betainate, the vinyl ester, or the combination thereof occurs at a temperature of less than 100 °C, or about 30 °C to about 100 °C, about 40 °C to about 100 °C, about 40 °C to about 90 °C, about 40 °C to about 80 °C, about 50 °C to about 80 °C, about 50 °C to about 70 °C, or about 60 °C to about 70 °C. In some embodiments, the contacting of the polysaccharide and the vinyl betainate, the vinyl ester, or the combination thereof occurs for about 30 minutes to about 300 minutes, about 30 minutes to about 250 minutes, about 30 minutes to about 180 minutes, or about 60 minutes to about 180 minutes.

[0039] Also provided herein are cationic polysaccharides, including cationic polysaccharides made according to the methods provided herein. The cationic polysaccharides may have a structure that includes the following formula:

[0040] wherein Ra, Rb, and Rcare independently selected from hydrogen or a substituent of the following formula -

[0041] wherein at least one of Ra, Rb, and Rcis not hydrogen; wherein R is a C1-C12 hydrocarbyl comprising at least one positively charged heteroatom, and n is an integer from 10 to 100,000. The positively charged heteroatom may be a nitrogen atom of an amine, such as a primary7(1°), secondary (2°), or tertiary (3°) amine. Therefore, R may be of the following formula:

[0042] wherein R1is a divalent C1-C9 hydrocarbyl; wherein R2, R3, and R4are independently selected from hydrogen or a Ci-Ce hydrocarbyl, such as a C1-C5 hydrocarbyl, a C1-C4 hydrocarbyl, a C1-C3 hydrocarbyl, a C1-C2 hydrocarbyl, or a Ci hydrocarbyl (e.g., a methyl); and wherein the total number of carbon atoms in R1, R2, R3, and R4is 12 or less. The anion may be a halide, such as a chloride. In some embodiments, Ra, Rb, and Rcare independently selected from hydrogen or°r

[0043] 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.

[0044] 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 2,000,000 g / mol, about 200 g / mol to about 1,000,000 g / mol, about 200 g / mol to about 500,000 g / mol, about 200 g / mol to about 100,000 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.

[0045] 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.

[0046] The phrases “Ch- hydrocarbyl,” “C2-C4hydrocarbyl.” 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.

[0047] 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., l-ethyl-4-methyl-cyclohexyl). Representative alkenyl moieties include vinyl, allyl, 1-butenyl, 2-butenyl. isobutylenyl, 1 -pentenyl, 2-pentenyl, 3-methyl- 1-butenyl, 2-methyl-2-butenyl, 2,3-dimethyl-2-butenyl, I -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, benzyl, and the like, including any heteroatom substituted derivative thereof.

[0048] 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 toone or more carbon atoms of the chemical structure or moiety (e.g., a “substituted’' C4 hydrocarbyl may include, but is not limited to, diethyl ether moiety, an ethyl acetate moiety, a methoxymethyl acetate moiety, a methyl propionate moiety, an A V-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 aryl Co 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, alkylcarbonyloxy (-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-aryl alkyl), carboxyl, carboxylic acid, cyano, ester, ether (e.g., methoxy, ethoxy), halo, haloalkyl (e.g., -CCI3, -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-).

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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 tothe 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.

[0053] 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.

[0054] The terms “a,” “an,” and “the” are intended to include plural alternatives, e.g., at least one. For instance, the disclosure of “a polysaccharide”, “a liquid”, and the like, is meant to encompass one, or mixtures or combinations of more than one polysaccharide, liquid, and the like, unless otherwise specified.

[0055] 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 alkyd, (iii) A may be a Ci alkyl, and B may be a C2 alkyl, etc.

[0056] 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, if Applicant discloses, in some embodiments, that a degree of substitution is about 1.5 to about 2.5, then this range should be interpreted as encompassing about 1.5 and about 2.5 and further encompasses “about” each of 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, and 2.4, including any ranges and sub-ranges between any of these values.

[0057] As used herein, the term “about” means plus or minus 10 % of the numerical value of the number with which it is being used.EXAMPLES

[0058] The present disclosure is further illustrated by the following examples, which are not to be construed in any way as imposing limitations upon the scope thereof. On thecontrary, it is to be clearly understood that resort may be had to various other aspects, embodiments, modifications, and equivalents thereof which, after reading the description herein, may suggest themselves to one of ordinary skill in the art without departing from the spirit of the present invention or the scope of the appended claims. Thus, other aspects of this disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the embodiments disclosed herein.Example 1 - Materials and Methods

[0059] Unactivated “Methyl” Betainates. Microcrystalline cellulose Avicel® PH-101 (Sigma Aldrich, USA) and potato starch were selected as model bio-based polymer materials. Superbase ionic liquid [mTBNH][0Ac] also was prepared. The corresponding reactive esters and carbamates were prepared, as explained below, by adapting different synthetic procedures, where the required starting materials were purchased from Sigma Aldrich or TCI Europe.

[0060] General workflow diagrams are provided at FIG. 1A, FIG. IB, and FIG. 1C.Initial scale experiments were first conducted to determine suitable reaction conditions. After finding suitable reaction conditions, selected derivatives / materials were prepared on a gram scale for further testing.

[0061] Chemical characterization of the reactions and their products were performed using liquid-state NMR spectroscopy on a Bruker NEO Avance (600 MHz IH-frequency). 'H and13C spectra were obtained either in the ionic liquid mixture (after dilution with DMSO-de) or in D2O, or in [P4444][OAc]: DMSO-de (20:80 wt%).

[0062] Initial studies of possible reaction pathways were performed with cellulose in the SB-IL [mTBNH][0Ac] to validate the derivatization pathways. Typically for test scale, 50 mg of MCC was dissolved in 1 mL [mTBNH][0Ac] at 80 - 100 °C. Then added to the solution was the appropriate amount of reagent (e.g., 3 - 9 equiv. per AGU) and the reaction mixture was stirred for 1, 3, or 20 hours at the same temperature.

[0063] Afterward, the reaction mixture was diluted with 1 mL DMSO-de and was analyzed by1H.13C, and diffusion edited1H NMR. After assessing the findings, some of the proposed pathways were modified or substituted, and new ideas were tested in a similar manner. Additionally, if the test reactions were not performing well, or not at all, in selected examples the solvent system was changed in order to evaluate further the reaction conditions. The test scale experiments for potato starch were performed similarly for cellulose. Upon upscaling the selected experiments, the developed reaction conditions, e.g.. concentrations,solvents, reagents, temperatures and times, were roughly optimized and reactions were scaled up to gram scale, and replicated.Example 2 - Cationic Cellulose Esters

[0064] In this example, 2 -methoxy -TV, iV, A-trimethyl-2-oxoethan- 1-aminium chloride (methyl betainate) was used.

[0065] In this example, a sustainable procedure for cellulose transesterification was used, which utilized simple methyl esters as the reagents (see Todorov, A. R. et al. RSC Adv., 2023, 13, 5983-5992). To test this reaction pathway, methyl ester of betaine was prepared using two different approaches, as depicted in the following schemeScheme 1. Synthesis of Ci Cationic Methyl Ester

[0066] The direct amination / cationization approach for the preparation of the betaine methyl ester was preferred, at least in some instances, over the Fisher esterification because the isolation of the product was easier, and its purity was higher.

[0067] Initial reaction tests with cellulose in the [mTBNH][OAc] ionic liquid were discouraging (Scheme 2): no cationic product was formed, and the only presented product was cellulose acetate, regardless of reaction time or temperature. This direct approach led to the formation of a stable ester (acetate), possibly due to several transesterification reactions that took place almost simultaneously.wccSO, 100, 120,;'C Not observed Only product Scheme 2. Attempted Cellulose Esterification with Methyl Betainate

[0068] In view of this outcome, the anion of the methyl betainate was exchanged from chloride to acetate. However, the outcome remained the same and only cellulose acetate was formed.

[0069] The presence of methyl acetate also was observed in the reaction mixtures, which indicated that the methyl betainate might have undergone transesterification in these reaction conditions. To verify this phenomenon, the cellulose was omitted, and the reaction was monitored (scheme 3).Scheme 3. Transesterification of Methyl Betainate

[0070] The results were clear: methyl acetate was formed in less than an hour in these conditions, which then caused the observed cellulose acetylation. To slow down the transesterification of the methyl betainate, acetic acid was added to the SB-IL (rendering the [mTBNH][OAc] less basic) and anew SB-IL was prepared, [mTBNH][CF3COO] (i.e., an anion that would lead to an unstable ester). The decomposition was slowed down, but not enough to allow the reaction with cellulose to succeed properly.

[0071] A solvent system other than the SB-ILs was then tried. Reaction tests were performed in the classical cellulose solvent system DMA-LiCl without or with addition of a base catalyst (weak or strong organic base e g., pyridine or mTBN). Despite these efforts, a premature decomposition of the methyl betainate was observed, and no desired cationic cellulose product was formed. Next, the methyl betainate was activated with Lewis acids, e.g., ZnCk and Zn(OAc)2, but the results were similar and no desired product was formed.

[0072] Methyl esters of betaine homologues. To address instability, the carbon chain between the ester and the cationic functionality was lengthened from 1 carbon to two or three. Utilizing the already-tested direct amination / cationization approach. C2 and C3 methyl betainate homologues were synthesized (scheme 4). To verify their stability, the newly prepared methyl esters were subjected to the same reaction conditions as the methyl betainate. The C2 derivative showed a very rapid decomposition rate and was a less stable reagent, while the C3 cationic methyl ester was stable over a long period of time (20 h) (scheme 4).Scheme 4. Synthesis of C2 and C3 Cationic Methyl Esters and Stability Tests

[0073] The cellulose modification with the C3 cationic methyl ester was successful and a cationic cellulose derivative with DS of 0.2 was obtained (scheme 5). This synthesis employed [mTBNH][OAc], 3 equivalents of C3 methyl ester, 100 °C, and 20 hours of reaction time. The product was soluble in acidic water (10 m-% of acetic acid).CCScheme 5. Synthesis of C3 Cationic Cellulose Ester and its Dissolution

[0074] In order to increase the DS, the synthesis was slightly modified (9 equivalents of reagent), and repeated on a 5g scale. Also, the newly prepared material was (i) water soluble, and (ii) 10 % acetic acid in water soluble, with a degree of substitution 0.45. A sample of this material was subjected to further analysis. The results indicated that the C3 cationic cellulose derivative was inherently stable, which, in turn, may result in poor (bio)degradability.

[0075] Activated ‘vinyl ’ betainates. Attempted was a cationization with activated Cl esters as reagents. First, a method was developed for preparing activated betainates similar to the direct amination / cationization approach, where vinyl betainates (N,N,N-ethyl or N,N,N-methyl) were obtained in nearly quantitative yields (scheme 6).Scheme 6. Synthesis of Activated C 1 Cationic Esters

[0076] N, N, N-triethyl-2-oxo-2-(vinyloxy)ethan-l-aminium chloride (vinyl ethyl betaincite). Initially, the activated N, N, N- triethyl analogue ('vinyl ethyl betainate’) was utilized in the derivatization process, because these materials have exhibited somewhat better stability of the obtained derivatives, and due to their availability. The tested reactions showed that the cationic Cl cellulose product was obtained together with some cellulose acetate (scheme 7). The initially selected reaction conditions w ere 3 equivalents of the activated betainate, 20 h. 60 °C and [mTBNH][0Ac] as a reaction mediamajor product minor product Scheme 7. Synthesis of Cl Cationic Cellulose Ester Through Activated Betaine Esters

[0077] Surprisingly, upon upscaling, the degree of substitution of the isolated Cl cationic product was significantly different than in the case of the test scale experiments. To understand this observation, a series of optimization and kinetic experiments was performed, and it was determined that the minor cellulose acetate product (z.e., side reaction) could be minimized using a shorter reaction time. The optimal time for the reaction was 30 minutes, where this side product was not found.

[0078] However, with longer reaction times, the amount of the acetate side product continued to increase, because its formation seemed to result from the decomposition of the cellulose Cl cationic material (i.e., desired product reacting further to cellulose acetate). In view of this observation, the reaction conditions were re-optimized to minimize overall reaction time. Even though the reaction of cellulose with vinyl betainate worked well, there were still some issues in the isolation method(s). Originally, ethanol precipitation / washing of the product was used, but that caused partial hydrolysis of the product, which was reflected in repeatability of the synthesis. Nevertheless, this was regarded as a minor issue and could be circumvented by proper optimization of the isolation process.

[0079] Vinyl ester of betaine as the reagent was a feasible pathway to obtain cationic cellulose derivatives.

[0080] N, N, N-trimethyl-2-oxo-2-(vmyloxy)ethan-l-aminium chloride (vinyl betainate). In view of the reactions of the W V-triethyl version of betaine, it was decided to change the reagent to vinyl betainate (scheme 8).Scheme 8. Synthesis of Cl Cationic Cellulose Ester Through Activated Vinyl Betaine Ester

[0081] Primary experiments revealed quickly that only 30 minutes of reaction time was required in order to achieve a desirable degree of substitution (and to minimize the formation of cellulose acetate). To elaborate the isolation procedure upon upscaling, different non-nucleophilic solvents, e.g., acetone, toluene or dioxane, were used for the washing of the product. Basically, all performed as expected, but utilizing acetone proved to be the most effective option, in this example, to remove traces of the IL.

[0082] The prepared Cl cationic cellulose materials were water soluble. To remove residual impurities e.g., SB-IL, betaine (from decomposed vinyl betainate), etc., their easy solubility was exploited, and a simple purification procedure was designed. After a quick dissolution in water, the cationic cellulose material was precipitated with acetone. Then, the formed solids were filtered and washed with some additional acetone, thereby providing a purified Cl cationic cellulose material. Notably, some minor hydrolysis might have taken place, but with short treatment times this was not a significant concern.

[0083] Other activated betaine esters. As the synthesis of vinyl betainate was likely not optimal for an industrial scale, other methods to activate esters were screened for their reactivity with cellulose. Commonly, the activation groups used for transesterification reactions have a relatively electron deficient character, e.g., pentafluorophenol, / ?-nitrophenol. etc. To elaborate their utilization, other activated betaine esters were prepared (scheme 9).; Fisher esterification;Scheme 9. Synthesis of Activated Cl Cationic Esters

[0084] Additionally, to the p-nitrophenol it was decided to utilize hexafluoro isopropanol, instead of the typically used pentafluorophenol. The derivatization trials showed that the HFIP betainate w as a very potent substitute to the vinyl betainate.

[0085] The obtained Cl cationic cellulose ester from the HFIP activation possessed properties that were similar to those of the one obtained previously (from vinyl betainate).However, the utilization of perfluorinated compounds have some drawbacks (e.g., some are not optimal for industry). The utilization of the p-nitrophenol activation in the derivatization process w as somewhat unsuccessful because the reagent decomposed rapidly in the tested reaction conditions.

[0086] Additionally, it was decided to change the reaction media for some of the activated betainates (vinyl and / ?-mtropheny I), and to try once again the cellulose derivatization. Testing also was performed using the classical cellulose solvent system DMA-LiCl, but the p-nitrophenyl activated betainate still decomposed rapidly.

[0087] Further, the vinyl betainate did not produce any desired product in DMA / LiCl. By optimizing the reaction conditions further via the addition of a mild or strong organic base (pyridine or mTBN), some product was produced, though the reaction was very sluggish. The reaction of the ‘mercerized’ cellulose was tested with vinyl betainate in water, but no Cl cationic ester was formed.Example 3 - Starch Esters

[0088] The cationization pathway to obtain cationic cellulose esters with vinyl betainate was further tested for derivatization of starch. Initially, the same reaction conditions used for the preparation of cellulose Cl cationic ester were tried (3 equivalents of vinyl betainate at 65 °C, in the SB-IL [mTBNH][0Ac]). How ever, the reaction did not proceed to a desirable extent.

[0089] Also, the previously used activated esters as well as the methyl betaine ester were tested in the same reaction conditions, but they did not yield any product (scheme 10).Scheme 10. Attempted Synthesis of Cl Cationic Starch Ester through Activated Betaine Esters and Methyl Betaine Ester

[0090] It was discovered that the tested potato starch did not properly dissolve into the reaction media (IL). This was an unexpected result, since the SB-IL is generally an excellent cellulose solvent and dissolves a variety of natural (like silk) and synthetic polymers (like nylon).

[0091] To overcome this solubility problem, a reaction in water was tested. The first trials in water were discouraging. The potato starch was well dissolved in the water, but it was not reactive at the attempted temperatures, even at 90 °C. An attempt was made to activate the starch by alkaline pre-treatment similarly to the cellulose mercerization process. The derivatization of the alkaline pre-treated starch with vinyl betainate was successful and the prepared material was soluble in cold water.

[0092] Prompted by the good reactivity of the pre-treated starch, it was decided to pursue reaction conditions w here a pre-activation of the starch was not needed. To try this approach, it was decided to use different concentrations of NaOH in water for alkaline activation and different concentrations of AcOH in water for acidic activation. The concentrations of NaOH or AcOH in water were varied from 0.01M to 10M and the tests results are summarized in table 1.*DS is an estimate fromXH NMR of reaction mixtures.Table 1. Cationic Starch Betainate Formation in Various Conditions

[0093] After some optimization, 20-25 mol% NaOH (compared to the vinyl betainate) was optimal, in this example, for DS and a rather short (~lh) reaction time.Extending the reaction time further to 20 hours did not change the reaction outcome, but may have affected the work up and especially the removal of the decomposed vinyl betainate (upon hydrolysis the vinyl betainate was transformed to betaine and acetaldehyde).Furthermore, the amount of the used vinyl betainate was decreased from 3 equivalents per AGU to 2 or 1 equivalent. In all cases, the desired Cl cationic starch product was formed, with a slight decrease in the degree of substitution (0.22 vs. 0.15 vs. 0.10, respectively).

[0094] Moreover, it was decided to assess the concentration of starch and its effect over the reaction outcome (table 1). The performed experiments showed a clear trend of increase in the DS with the increase of the starch concentration. This behavior was somewhat predictable as there were competing reactions involved in the modification (hydrolysis and starch modification). Notably, the '‘reaction mixture” became increasingly viscous and decreased the efficiency of mixing, which might have resulted in the inhomogeneous endproduct in the laboratory scale experiments. However, it was likely that these effects could have been avoided by using proper high-consistency mixers / reactors.

[0095] A 5 g scale reaction at 15 weight % was performed and the isolated material was subjected to further studies. There were some unexpected difficulties in the isolation of the product. The isolated product was not pure and contained some amount of vinyl betainate(~9 %) and betaine (~18%). Another reaction was performed at 1 g scale in the same conditions and the pure isolated material was subjected to further studies. The DS of both pure and impure samples was ~0.45.

[0096] Also upscaled (0.5g of potato starch) was the test reaction, and obtained was a cold water soluble Cl cationic starch with a degree of substitution of ~0.2 (scheme 11).Scheme 11. Synthesis of Cl Cationic Starch Ester through Vinyl Betaine Ester in Water

[0097] Further upscaling (5g of potato starch) proceeded similarly, although the Cl cationic starch material was obtained with a slightly lower DS of 0.1. Nevertheless, this material was cold water soluble and both samples were subjected to further studies. Most likely the decrease in the DS was due to hydrolysis during the work up, which could be addressed with adjustments.

[0098] An interesting feature of the reaction process was noticed during the optimization work; the pH of the reaction changed from basic to acidic and it was noticed that the Cl cationic starch ester was more stable in acidic conditions. Plausibly, the pH change emerged from the hydrolysis of the vinyl betainate, releasing acidic betaine (and acetaldehyde, scheme 12).Scheme 12. Hydrolysis of Vinyl Betaine Ester in Water

[0099] Kinetic experiments in neutral water at 65 °C showed that the vinyl betainate was hydrolysed almost completely after 22 hours (picture 1).LISTING OF EMBODIMENTS

[0100] The following is a non-limiting listing of embodiments of the disclosure.

[0101] Embodiment 1. A method for producing a cationic polysaccharide, the method comprising, consisting essentially of, or consisting of contacting -

[0102] (i) a polysaccharide, and

[0103] (ii) a vinyl betainate, a vinyl ester, or a combination thereof to produce the cationic polysaccharide.

[0104] Embodiment 2. The method of Embodiment 1, wherein the polysaccharide does not comprise or consist of an a-glucan, such as an a- 1,3 -glucan.

[0105] Vinyl Betainates / Vinyl Esters

[0106] Embodiment 3. The method of any of the preceding Embodiments, wherein the vinyl betainate, the vinyl ester, or the combination thereof comprises, consists essentially of, or consists of one or more compounds of the following formula:

[0107] wherein R is a C1-C12 hydrocarbyl comprising at least one positively charged heteroatom; and

[0108] wherein R’ is a C1-C12 hydrocarbyl, optionally comprising at least one unsaturated bond, at least one electron withdrawing substituent, or a combination thereof.

[0109] Embodiment 4. The method of any of the preceding Embodiments, wherein R’ comprises a double bond.

[0110] Embodiment 5. The method of any of the preceding Embodiments, wherein R’ comprises a halo substituent, such as a fluoro substituent.

[0111] Embodiment 6. The method of any of the preceding Embodiments, wherein R' comprises at least one trifluoromethyl moiety’.

[0112] Embodiment 7. The method of any of the preceding Embodiments, wherein R’ comprises at least one nitro substituent.

[0113] Embodiment 8. The method of any of the preceding Embodiments, wherein R’ comprises an aryl group substituted with at least one nitro substituent.

[0114] Embodiment 9. The method of any of the preceding Embodiments, wherein R’ comprises a 4-nitrophenyl group.

[0115] Embodiment 10. The method of any of the preceding Embodiments, wherein the positively charged heteroatom is a nitrogen atom of an amine, such as a primary (1°), secondary (2°). or tertiary (3°) amine.

[0116] Embodiment 11. The method of any of the preceding Embodiments, wherein R is of the following formula:

[0117] wherein R1is a divalent C1-C9 hydrocarbyl;

[0118] wherein R2, R3, and R4are independently selected from hydrogen or a Ci-Ce hydrocarbyl, such as a C1-C5 hydrocarbyl, a C1-C4 hydrocarbyl, a C1-C3 hydrocarbyl, a C1-C2 hydrocarbyl, or a Ci hydrocarbyl (e.g., a methyl); and

[0119] wherein the total number of carbon atoms in R1, R2, R3, and R4is 12 or less.

[0120] Embodiment 12. The method of any of the preceding Embodiments, wherein the anion is a halide, such as a chloride.

[0121] Embodiment 13. The method of any of the preceding Embodiments, wherein the vinyl betaine, the vinyl ester, or the combination thereof is selected from the group consisting of-Liquids

[0122] Embodiment 14. The method of any of the preceding Embodiments, wherein the contacting of (i) the polysaccharide and (ii) the vinyl betainate, the vinyl ester, or the combination thereof occurs, at least in part, in a liquid; wherein optionally the polysaccharide is soluble, partially soluble, or insoluble in the liquid.

[0123] Embodiment 15. The method of Embodiment 14, wherein the liquid comprises, consists essentially of, or consists of an ionic liquid.

[0124] Embodiment 16. The method of Embodiment 15, wherein the ionic liquid comprises, consists essentially of, or consists of a superbase ionic liquid.

[0125] Embodiment 17. The method of Embodiment 16, wherein the superbase ionic liquid comprises, consists essentially of, or consists of [mTBNEI] [O Ac].

[0126] Embodiment 18. The method of any of Embodiments 14 to 17, wherein the liquid comprises, consists essentially of, or consists of water or an organic liquid, such as a polar organic liquid.

[0127] Embodiment 19. The method of any of Embodiments 14 to 18, wherein the polysaccharide is soluble or partially soluble in the liquid.

[0128] Pre-treatment of Polysaccharide

[0129] Embodiment 20. The method of any of the preceding Embodiments, further comprising, consisting essentially of, or consisting of pre-treating the polysaccharide prior to the contacting of the polysaccharide and the vinyl betainate, the vinyl ester, or the combination thereof.

[0130] Embodiment 21. The method of Embodiment 20, wherein the pre- treating of the polysaccharide comprises, consists essentially of, or consists of contacting the polysaccharide and a base.

[0131] Embodiment 22. The method of Embodiment 21, wherein the base comprises, consists essentially of, or consists of NaOH.

[0132] Embodiment 23. The method of Embodiment 21 or 22, wherein a concentration of the base is about 0.001 M to about 0.5 M, about 0.01 M to about 0.5 M, about 0.01 M to about 0.25 M, about 0.01 M to about 0.1 M.

[0133] Embodiment 24. The method of any one of Embodiments 21 to 23, wherein the polysaccharide is contacted with about 1 mol% to about 30 mol%, about 1 mol% to 25 mol%, about 10 mol% to about 25 mol%, about 15 mol% to about 25 mol%, or about 20 mol% to about 25 mol% of the base, relative to the vinyl betainate, the vinyl ester, or the combination thereof.Concentrations / Mole Ratios

[0134] Embodiment 25. The method of any of the preceding Embodiments, wherein a concentration of the polysaccharide in the liquid (prior to the contacting of the polysaccharide and the vinyl betainate, vinyl ester, or the combination thereof) is about 0.01 wt% to about 30 wt%, about 0.01 wt% to about 25 wt%, about 0.01 wt% to about 20 wt%, about 0.01 wt% to about 15 wt%, about 0.01 wt% to about 10 wt%, about 0.01 wt% to about 5 wt%, about 0.01wt% to about 2.5 wt%, about 0.01 wt% to about 0.5 wt%, about 0.1 wt% to about 0.5 wt%, based on the total weight of the liquid and the polysaccharide.

[0135] Embodiment 26. The method of any of the preceding Embodiments, wherein the contacting of the polysaccharide and the vinyl betainate, the vinyl ester, or the combination thereof comprises, consists essentially of, or consists of contacting the polysaccharide with about 1 to about 5, about 1 to about 4, about 1 to about 3, or about 2 to about 3 equivalents of the vinyl betainate, the vinyl ester, or the combination thereof per cyclic moiety of the polysaccharide.Polysaccharide

[0136] Embodiment 27. The method of any of the preceding Embodiments, wherein the polysaccharide is selected from starch, cellulose, dextran, glycogen, pullulan. or a combination thereof.Degree of Substitution

[0137] Embodiment 28. The method of any of the preceding Embodiments, wherein the cationic polysaccharide has a degree of substitution (as determined by 'H NMR) of about 0.01 to about 3, about 0.01 to about 2.5, about 0.01 to about 2, about 0.01 to about 1.5, about 0.01 to about 1, about 0.01 to about 0.8, about 0.01 to about 0.6, about 0.03 to about 0.6, about 0.03 to about 0.55, about 0.03 to about 0.5, about 0.03 to about 0.45, about 0.03 to about 0.4, about 0.03 to about 0.35, about 0.03 to about 0.3. about 0.03 to about 0.25, about 0.03 to about 0.2, about 0.03 to about 0.15, or about 0.03 to about 0.1.Reaction Conditions

[0138] Embodiment 29. The method of any of the preceding Embodiments, wherein the contacting of the polysaccharide and the vinyl betainate, the vinyl ester, or the combination thereof occurs at a temperature of less than 100 °C, or about 30 °C to about 100 °C, about 40 °C to about 100 °C, about 40 °C to about 90 °C, about 40 °C to about 80 °C, about 50 °C to about 80 °C, about 50 °C to about 70 °C, or about 60 °C to about 70 °C.

[0139] Embodiment 30. The method of any of the preceding Embodiments, wherein the contacting of the polysaccharide and the vinyl betainate, the vinyl ester, or the combination thereof occurs for about 30 minutes to about 300 minutes, about 30 minutes to about 250 minutes, about 30 minutes to about 180 minutes, or about 60 minutes to about 180 minutes.Further Elements

[0140] Embodiment 31. The method of any of the preceding Embodiments, wherein when the liquid comprises, consists essentially of, or consists of the ionic liquid, the methodfurther comprises, consists essentially of, or consists of contacting a mixture comprising the ionic liquid and the cationic polysaccharide with water to dissolve the cationic polysaccharide, and separate the cationic polysaccharide from the ionic liquid; and optionally precipitating the cationic polysaccharide.

[0141] Embodiment 32. The method of any of the preceding Embodiments, wherein the contacting of the polysaccharide and the vinyl betainate, the vinyl ester, or the combination thereof produces one or more side products, and the method further comprises, consists essentially of, or consists of collecting the one or more side products.

[0142] Embodiment 33. The method of Embodiment 32, wherein the side product comprises, consists essentially of or consists of acetaldehyde.

[0143] Embodiment 34. The method of any of the preceding Embodiments, further comprising, consisting essentially of, or consisting of washing the cationic polysaccharide, wherein optionally the washing of the cationic polysaccharide comprises, consists essentially of, or consists of contacting the cationic polysaccharide and a non-nucleophilic liquid (e.g., solvent), such as acetone, toluene, dioxane, etc.Cationic Polysaccharides

[0144] Embodiment 35. A cationic polysaccharide produced according to the method of any of the preceding Embodiments.

[0145] Embodiment 36. A cationic polysaccharide, wherein the cationic polysaccharide has a structure comprising the following formula:

[0146] wherein Ra, Rb, and Rcare independently selected from hydrogen or a substituent of the following formula -

[0147] wherein at least one of Ra, Rb, and Rcis not hydrogen;

[0148] wherein R is a C1-C12 hydrocarbyl comprising at least one positively charged heteroatom, and n is an integer from 10 to 100,000.

[0149] Embodiment 37. The cationic polysaccharide of any of the preceding Embodiments, wherein the positively charged heteroatom is a nitrogen atom of an amine, such as a primary (1°), secondary (2°), or tertiary (3°) amine.

[0150] Embodiment 38. The cationic saccharide of any of the preceding Embodiments, wherein R is of the following formula:

[0151] wherein R1is a divalent C1-C9 hydrocarbyl;

[0152] wherein R2, R3, and R4are independently selected from hydrogen or a Ci-Ce hydrocarbyl, such as a C1-C5 hydrocarbyl, a C1-C4 hydrocarbyl, a C1-C3 hydrocarbyl, a C1-C2 hydrocarbyl, or a Ci hydrocarbyl (e.g., a methyl); and

[0153] wherein the total number of carbon atoms in R1, R2, R3, and R4is 12 or less.

[0154] Embodiment 39. The cationic polysaccharide of any of the preceding Embodiments, wherein the anion is a halide, such as a chloride.

[0155] Embodiment 40. The cationic polysaccharide of any of the preceding Embodiments, wherein the Ra, Rb, and Rcare independently selected from hydrogen orcr

[0156] Embodiment 41. The cationic polysaccharide of any of the preceding Embodiments, wherein the cationic polysaccharide is biodegradable.

[0157] Embodiment 42. The cationic polysaccharide of any of the preceding Embodiments, wherein one or more products produced by a hydrolysis reaction of the cationic polysaccharide are biodegradable.

[0158] Embodiment 43. The cationic polysaccharide of any of the preceding Embodiments, wherein a hydrolysis of the cationic polysaccharide occurs when the cationic polysaccharide is disposed in water, such as at a pH of at least 6.

[0159] Embodiment 44. A composition comprising, consisting essentially of, or consisting of the cationic polysaccharide of any of the preceding Embodiments.

[0160] Embodiment 45. 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.Methods of Purification

[0161] Embodiment 46. A method of purification, the method comprising, consisting essentially or, or consisting of-

[0162] providing an amount of water; and

[0163] contacting the water and a cationic polysaccharide of any of the preceding Embodiments.

Claims

Claims -1. A method producing a cationic polysaccharide, the method comprising:contacting (i) a polysaccharide, and (ii) a vinyl betainate, a vinyl ester, or a combination thereof to produce the cationic polysaccharide;wherein the polysaccharide does not include an a-glucan.

2. The method of claim 1, wherein the vinyl betainate, the vinyl ester, or the combination thereof comprises a compound of the following formula:wherein R and R’ are independently selected from a C1-C12 hydrocarbyl, wherein R comprises at least one positively charged heteroatom.

3. The method of claim 2, wherein R’ comprises at least one unsaturated bond, at least one electron withdrawing substituent, or a combination thereof.

4. The method of claim 3, wherein R’ comprises a double bond, a halo substituent, a nitro substituent, or a combination thereof.

5. The method of claim 2, wherein R is of the following formula:wherein R1is a divalent C1-C9 hydrocarbyl; andwherein R2, R3, and R4are independently selected from hydrogen or a C1-C6hydrocarbyl; andwherein the total number of carbon atoms in R1, R2, R3, and R4is 12 or less.

6. The method of claim 2, wherein the anion is a halide.The method of claim 1, wherein the vinyl betaine, the vinyl ester, or the combination thereof is selected from the group consisting of-8. The method of claim 1, wherein the contacting of (i) the polysaccharide and (ii) the vinyl betainate. the vinyl ester, or the combination thereof occurs at least partially in a liquid.

9. The method of claim 8, wherein the liquid comprises an ionic liquid.

10. The method of claim 8, wherein the liquid comprises water or an organic liquid.

11. The method of claim 8, wherein the polysaccharide is soluble or partially soluble in the liquid.

12. The method of claim 1, further comprising:pre-treating the polysaccharide prior to the contacting of the polysaccharide and the vinyl betainate, the vinyl ester, or the combination thereof;wherein the pre-treating of the polysaccharide comprises contacting the polysaccharide and a base.

13. The method of claim 1, wherein the polysaccharide is contacted with about 1 to about 3 equivalents of the vinyl betainate, the vinyl ester, or the combination thereof per cyclic moiety of the polysaccharide.

14. A cationic polysaccharide having a structure comprising the following formula:wherein Ra, Rb, and Rcare independently selected from hydrogen or a substituent of the following formula -wherein at least one of Ra, Rb, and Rcis not hydrogen;wherein R is a C1-C12 hydrocarbyl comprising at least one positively charged heteroatom, and n is an integer from 10 to 100,000.

15. A method of purification, the method comprising:providing an amount of water; andcontacting the amount of water and the cationic polysaccharide of claim 14.

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