Derivatives of native lignin
One aspect of the invention relates to lignin derivatives having an aliphatic hydroxyl content of 2.35 mmol/g lignin or less, and the preparation method thereof. The lignin derivatives have a desired antioxidant activity characterized by the normalized radical scavenging index (RSI). Another aspect of the invention relates to compositions comprising the lignin derivative. Another aspect of the invention relates to a use of the lignin derivatives comprising incorporating the lignin derivatives into polymer compositions.
1. A lignin derivative wherein said lignin derivative has an aliphatic hydroxyl content of from 0.001 mmol/g to 2.35 mmol/g and a weight average molecular weight (M w ) of from about 500 g/mol to about 5000 g/mol, the lignin derivative having a normalized RSI of 15 or greater.
2. The lignin derivative according to claim 1 wherein the derivative has an aliphatic hydroxyl content of about 2.25 mmol/g or less.
3. The lignin derivative according to claim 1 wherein the derivative has an aliphatic hydroxyl content of about 1.75 mmol/g or less.
4. The lignin derivative according to claim 1 wherein the derivative has an aliphatic hydroxyl content of about 0.1 mmol/g or greater.
5. The lignin derivative according to claim 1 wherein the lignin is derived from hardwood biomass.
6. The lignin derivative according to claim 1 wherein the lignin is derived from softwood biomass.
7. The lignin derivative according to claim 1 wherein the lignin is derived from annual fibre biomass.
8. The lignin derivative according to claim 1 wherein the lignin is derived from biomass comprising Populus spp., Eucalyptus spp., Acacia spp., or combinations/hybrids thereof.
9. The lignin derivative according to claim 1 wherein the biomass comprises Populus tremuloides, Eucalyptus globulus, Acacia dealbata , or combinations/hybrids thereof.
10. The lignin derivative according to claim 1 wherein the lignin is derived from biomass comprising pine, spruce, or combinations/hybrids thereof.
11. The lignin derivative according to claim 1 wherein the lignin is derived from biomass comprising Pinus radiata, Pinus taeda , BC spruce, or combinations/hybrids thereof.
12. The lignin derivative according to claim 1 wherein the lignin is derived from biomass comprising wheat straw, bagasse, corn cobs, or combinations/hybrids thereof.
13. The lignin derivative according to claim 1 wherein the derivative comprises alkoxy groups.
14. A use of the lignin derivative according to claim 1 as an antioxidant comprising incorporating the lignin derivative into a polymer composition.
15. The use of the lignin derivative according to claim 14 , wherein the polymer composition is a thermoplastic.
16. A use of the lignin derivative according to claim 1 , as an antioxidant comprising incorporating the lignin derivative into a nutritional supplement, nutraceutical, animal feed, and/or functional food.
17. A composition comprising the lignin derivative according to claim 1 and a polymer-forming component.
18. A thermoplastic composition comprising the lignin derivative according to claim 1 .
19. A polyolefin composition comprising the lignin derivative according to claim 1 .
20. A method of producing the lignin derivative according to claim 1 , said method comprising:
a) pulping a fibrous biomass in a vessel with an organic solvent/water solvent solution to form a liquor, wherein:
i. the solution comprises about 30% or greater, by weight, of organic solvent; and
ii. the pH of the liquor is from about 1 to about 6;
b) heating the liquor to about 100° C. or greater;
c) maintaining the elevated temperature and pressure for 1 minute or longer;
d) separating the cellulosic pulps from the pulping liquor; and
e) recovering derivatives of native lignin.