REACTIVE EXTRUSION PROCESSES
One embodiment includes combining lignin, cyclic alkene carbonate, and a basic/alkaline compound and allowing the cyclic alkene carbonate and the basic/alkaline compound to modify the lignin to produce a hydroxyalkoxylated lignin. The cyclic alkene carbonate can act as a hydroxyalkoxylating reagent and the basic/alkaline compound can act as a catalyst.
1 . A method comprising:
combining lignin, cyclic alkene carbonate, and a basic/alkaline compound; and
allowing the cyclic alkene carbonate and the basic/alkaline compound to modify the lignin to produce a hydroxyalkoxylated lignin.
2 . The method of claim 1 , wherein the cyclic alkene carbonate acts as a hydroxyalkoxylating reagent and the basic/alkaline compound acts as a catalyst.
3 . The method of claim 1 , wherein the lignin is modified in a non-aqueous reaction media.
4 . The method of claim 1 , wherein the basic/alkaline compound includes an aliphatic, heterocyclic or aromatic amine having a pKa dissociation constant in the range of about 9 to about 13.
5 . The method of claim 1 , wherein the lignin, the cyclic alkene carbonate, and the basic/alkaline compound are combined in a continuous or semi-continuous reaction process.
6 . The method of claim 5 , wherein the continuous or semi-continuous reaction process is a continuous reactive extrusion process.
7 . The method of claim 6 , wherein the cyclic alkene carbonate and the basic/alkaline compound are not readily volatile at reaction temperatures but can be evaporated during the continuous reactive extrusion process.
8 . A method comprising:
combining lignin, a dialkyl carbonate, and a basic/alkaline compound; and
allowing the dialkyl carbonate and the basic/alkaline compound to modify the lignin to produce an alkoxylate-modified lignin.
9 . The method of claim 8 , wherein the dialkyl carbonate acts as an alkoxylating reagent and the basic/alkaline compound acts as a catalyst.
10 . The method of claim 8 , wherein the lignin is modified in a non-aqueous reaction media.
11 . The method of claim 8 , wherein the basic/alkaline compound includes an aliphatic, heterocyclic or aromatic amine having a pKa dissociation constant in the range of about 9 to about 13.
12 . The method of claim 8 , wherein the lignin, the dialkyl carbonate, and the basic/alkaline compound are combined in a continuous or semi-continuous reaction process.
13 . The method of claim 12 , wherein the continuous or semi-continuous reaction process is a continuous reactive extrusion process.
14 . The method of claim 13 , wherein the dialkyl carbonate and the basic/alkaline compound are not readily volatile at reaction temperatures but can be evaporated from the continuous reactive extrusion process.
15 . A method to produce a hydroxyalkoxylated lignin, the method comprising:
using a reactive solvent as a lignin-chemically-modifying reagent, wherein the reactive solvent dissolves un-fractionated kraft lignin at a concentration greater than about thirty percent solids at 100° C. to produce the hydroxyalkoxylated lignin.
16 . The method of claim 15 , wherein the reactive solvent is propylene carbonate.
17 . The method of claim 15 , wherein the reactive solvent is a cyclic alkene carbonate or an alkyl carbonate.
18 . The method of claim 15 , wherein the hydroxyalkoxylated lignin is produced in a non-aqueous reaction media.
19 . The method of claim 15 , wherein the hydroxyalkoxylated lignin is produced in a continuous or semi-continuous reaction process.
20 . The method of claim 15 wherein the hydroxyalkoxylated lignin is produced in a reactive extrusion process.