Hemicellulose Compositions
Hemicellulose compositions are prepared by treating a cellulosic material with an extractant comprising a cellulose solvent and co-solvent. The hemicellulose compositions preferably comprise from 55 to 99 wt. % xylan and have distinct molecular weights, elemental metal ions, and intrinsic viscosities when compared to known hemicellulose compositions.
1 . A hemicellulose composition comprising from 55 to 99 wt. % xylan, based on the total dried weight of the hemicellulose composition.
2 . The hemicellulose composition of claim 1 , wherein the composition comprises from 55 to 80 wt. % xylan.
3 . The hemicellulose composition of claim 1 , wherein the composition comprises less than 0.3 wt. % mannan.
4 . The hemicellulose composition of claim 1 , wherein the composition comprises less than 0.1 wt. % mannan.
5 . The hemicellulose composition of claim 1 , wherein the composition comprises less than 5 wt. % glucan.
6 . The hemicellulose composition of claim 1 , wherein the composition comprises less than 0.1 wt. % arabinan.
7 . The hemicellulose composition of claim 1 , wherein the weight ratio of xylan to mannan is at least 200:1.
8 . The hemicellulose composition of claim 1 , wherein the weight ratio of xylan to mannan is at least 500:1.
9 . The hemicellulose composition of claim 1 , wherein the composition has a weight average molecular weight from 20,000 to 35,000 g/mol.
10 . The hemicellulose composition of claim 1 , wherein the composition has a number average molecular weight from 10,000 to 40,000 g/mol.
11 . The hemicellulose composition of claim 1 , wherein the composition has a Z-average molecular weight from 20,000 to 45,000 g/mol.
12 . The hemicellulose composition of claim 1 , wherein the composition has an intrinsic viscosity of at least 0.3.
13 . The hemicellulose composition of claim 1 , wherein the composition has an intrinsic viscosity of at least 0.34.
14 . The hemicellulose composition of claim 1 , wherein the composition comprises less than 5000 ppm sodium.
15 . The hemicellulose composition of claim 1 , wherein the composition comprises less than 250 ppm sodium.
16 . The hemicellulose composition of claim 1 , wherein the composition comprises less than 5000 ppm potassium.
17 . The hemicellulose composition of claim 1 , wherein the composition comprises less than 70 ppm potassium.
18 . The hemicellulose composition of claim 1 , wherein the hemicellulose composition is derived from a hardwood pulp.
19 . A hemicellulose composition comprising xylan and mannan in a weight ratio from 200:1 to 2000:1.
20 . A hemicellulose composition comprising from 55 to 99 wt. % xylan, less than 0.3 wt. % mannan, less than 5 wt. % glucan and less than 0.1 wt. % arabinan.