Derivatives of native lignin from softwood feedstocks
One aspect of the invention relates to softwood lignin derivatives having an aliphatic hydroxyl content of from about 2.5 mmol/g to about 7 mmol/g lignin, and the preparation method thereof. The lignin derivatives have a desired antioxidant activity characterized by radical scavenging index (RSI). Another aspect of the invention relates to compositions comprising the softwood lignin derivative. Another aspect of the invention relates to a use of the softwood lignin derivatives comprising incorporating the softwood lignin derivatives into polymer compositions.
1. A softwood lignin derivative recovered from a pulping process of a lignocellulosic biomass, said softwood lignin derivative having an aliphatic hydroxyl content of from about 2.5 mmol/g to about 7 mmol/g, and a weight average molecular weight of from about 500 g/mol to about 5000 g/mol, and a normalized RSI of about 10 to about 40.
2. The lignin derivative according to claim 1 , wherein the pulping process is selected from the group consisting of: steam explosion, dilute acid hydrolysis, ammonia fiber expansion, autohydrolysis, kraft and modifications thereof, soda pulping and modifications thereof, sulphite pulping, and organosolv processes.
3. The lignin derivative according to claim 1 , wherein the pulping process is a kraft process or a modification thereof.
4. The lignin derivative according to claim 1 , wherein the pulping process is an organosolv process.
5. The lignin derivative according to claim 1 , wherein the derivative has an aliphatic hydroxyl content of from about 2.75 mmol/g to about 5 mmol/g.
6. The lignin derivative according to claim 1 , wherein the lignin is derived from biomass comprising pine, spruce, or combinations/hybrids thereof.
7. The lignin derivative according to claim 1 , wherein the lignin is derived from biomass comprising Pinus radiata, Pinus taeda , spruce, or combinations/hybrids thereof.
8. The lignin derivative according to claim 1 , having a normalized RSI of about 15 to about 35.
9. The lignin derivative according to claim 1 , wherein the derivative comprises alkoxy groups.
10. The lignin derivative according to claim 1 , wherein the derivative comprises ethoxyl groups.
11. The lignin derivative according to claim 1 , wherein the derivative has an ethoxyl content of 1.4 mmol/g or less.
12. A composition comprising the derivative of claim 1 and a polymer-forming component.
13. A thermoplastic composition comprising the lignin derivative according to claim 1 .
14. A polyolefin composition comprising the lignin derivative according to claim 1 .
15. The lignin derivative according to claim 1 having a normalized RSI of about 24.56 to about 36.97.
16. The lignin derivative according to claim 1 having an aliphatic hydroxyl content of from about 2.6 mmol/g to about 3.81 mmol/g.