Chemically modified polyaminosaccharide by a hydrocarbyl sultone compound

A process for producing a chemically modified polyaminosaccharide, comprising:

• forming a mixture by admixing an organic solvent with an un-modified polyaminosaccharide having amino functional groups;
• alkylsulfonating the un-modified polyaminosaccharide by adding a hydrocarbyl sultone compound to the mixture under a reflux temperature of the organic solvent,
• wherein the hydrocarbyl sultone compound has a formula of:
• in which
• R1 is selected from —(CH2)x— (where x is an integer of 2 to 4) and —CH═CH—;
• and
• R2 is selected from H and a C1-C3 alkyl group;
• and
• wherein the organic solvent has less than 10% water and is selected from the group consisting of methanol, ethanol, isopropanol, butanol methoxypropanol, and combinations thereof;
• such that a predetermined proportion of the amino functional groups in the thus-produced chemically modified polyaminosaccharide is alkylsulfonated by the hydrocarbyl sultone compound via a covalent bond.

A composition comprising a chemically modified chitosan and sulfur, the composition capable of suppressing the depletion of the sulfur content to no more than 3% by weight upon being subjected to the treatment of an alkaline solution, the composition being produced by a process of alkylsulfonating an un-modified chitosan having amino functional groups by a hydrocarbyl sultone compound in the presence of an organic solvent under a reflux temperature of the organic solvent,

• wherein the hydrocarbyl sultone compound has a formula of:
• in which
• R1 is selected from —(CH2)x— (where x is an integer of 2 to 4) and —CH═CH—;
• and
• R2 is selected from H and a C1-C3 alkyl group;
• and
• wherein the organic solvent has less than 10% water and is selected from the group consisting of methanol, ethanol, isopropanol, butanol methoxypropanol, and combinations thereof;
• such that a predetermined proportion of the amino functional groups in the thus-produced chemically modified chitosan is alkylsulfonated by the hydrocarbyl sultone compound via a covalent bond.