HYDROPHOBICALLY-MODIFIED POLYSACCHARIDES AND USES THEREOF
Described herein are hydrophobically-modified polysaccharides, their manufacture, and their use in microencapsulation, typically of water-insoluble active materials.
1 . A process for synthesizing a hydrophobically-modified polysaccharide, the process comprising reacting a polysaccharide with a compound represented by formula (I)
G-R (I)
wherein
G is a carbonyl-containing functional group, and
R is a hydrophobic group.
2 . The process according to claim 1 , wherein G comprises an anhydride group, an aldehyde group, an acid halide group, a ketone group, or an amide group.
3 . The process according to claim 1 , wherein G is an anhydride group represented by the structure
wherein n is 0 or 1.
4 . The process according to claim 1 , wherein G is an aldehyde group.
5 . The process according to claim 1 , wherein R is a hydrocarbyl selected from the group consisting of alkyl, alkenyl, alkynyl, aryl, arylalkyl, arylalkenyl, and arylalkynyl, each being optionally substituted.
6 . The process according to claim 1 , wherein R is (C 1 -C 40 )hydrocarbyl.
7 . The process according to claim 1 , wherein the polysaccharide is a glucan, starch, amylose, amylopectin, glycogen, dextran, cellulose, mannan, xylan, lignin, araban, galactan, galacturonan, chitin, chitosan, glucuronoxylan, arabinoxylan, xyloglucan, glucomannan, pectin, arabinogalactan, carrageenan, agar, gum arabic, gum tragacanth, ghatti gum, karaya gum, carob gum, polygalactomannan, or a mixture thereof.
8 . The process according to claim 1 , wherein a degree of hydrophobic substitution (DS h) of the hydrophobically-modified polysaccharide is from 0.001 to 3.0.
9 . The process according to claim 1 , wherein an amount of the compound represented by formula (I) is from 1 to 99% by weight relative the amount of the polysaccharide.
10 . The process according to claim 1 , wherein the weight average molecular weight of the polysaccharide is from 1,000 g/mol to 10,000,000 g/mol.
11 . A hydrophobically-modified polysaccharide synthesized by the process according to claim 1 .
12 . A process for forming an emulsion, the process comprising mixing the hydrophobically-modified polysaccharide according to claim 11 , in aqueous solution or dispersion; with a water-insoluble active material, thereby forming the emulsion.
13 . The process according to claim 12 , wherein the water-insoluble active material comprises a flavor, fragrance, pro-fragrance, taste masking agent, taste sensate, malodor counteracting agent, vitamin, antibacterial agent, sunscreen active, antioxidant, anti-inflammatory agent, anesthetic, analgesic, antifungal agent, antibiotic, anti-viral agents, anti-parasitic agent, anti-infectious agent, anti-acne agent, dermatological active ingredient, enzymes and co-enzymes, skin whitening agent, anti-histamine, chemotherapeutic agent, insect repellent, or a mixture thereof.
14 . The process according to claim 12 , wherein the emulsion comprises discrete droplets having a droplet size from 0.1 μm to 200 μm.
15 . The process according to claim 12 , wherein the emulsion is further reacted with a crosslinker.
16 . The process according to claim 12 , wherein the emulsion formed is stable for at least 1 week.
17 . The process according to claim 12 , wherein the emulsion comprises one or more microcapsules, wherein the one or more microcapsules each comprise a core having the water-insoluble active material and a wall having the hydrophobically-modified polysaccharide.
18 . An emulsion formed according to the process of claim 12 .
19 . A microcapsule comprising a core having a water-insoluble active material and a wall having the hydrophobically-modified polysaccharide according to claim 11 .
20 . The microcapsule according to claim 19 , wherein the microcapsule has a size from 100 nm to 50 μm.
21 . The process according to claim 15 , wherein the crosslinker is a salt comprising at least one multivalent cation.
22 . The process according to claim 21 , wherein the crosslinker is CaCl 2 .
23 . The process according to claim 15 , wherein the crosslinker is a polyalkoxysiloxane.
24 . A microcapsule comprising a core having a water-insoluble active material and a wall having a hydrophobically-modified polysaccharide, wherein the hydrophobically-modified polysaccharide comprises a polysaccharide having at least one hydrophobic substituent, wherein the hydrophobic substituent is a (C 5 -C 45 )ether, (C 5 -C 45 )ester, or a mixture thereof.
25 . The microcapsule according to claim 24 , wherein the at least one hydrophobic substituent comprises a (C 1 -C 40 )hydrocarbyl.
26 . The microcapsule according to claim 24 , wherein the at least one hydrophobic substituent comprises at least one pendant carboxyl group.
27 . The microcapsule according to claim 24 , wherein the microcapsule has a size from 100 nm to 200 μm.
28 . The microcapsule according to claim 24 , wherein the polysaccharide is selected from the group consisting of a glucan, starch, amylose, amylopectin, glycogen, dextran, cellulose, mannan, xylan, lignin, araban, galactan, galacturonan, chitin, chitosan, glucuronoxylan, arabinoxylan, xyloglucan, glucomannan, pectin, arabinogalactan, carrageenan, agar, gum arabic, gum tragacanth, ghatti gum, karaya gum, carob gum, polygalactomannan, and combinations thereof.
29 . An emulsion comprising a plurality of the microcapsule according to claim 24 , wherein 75% to 100% of the microcapsules have a size from 100 nm to 200 μm.