Chemical modification of lignin and lignin derivatives
In one example implementation, a trans-esterified HPL can include a HPL and a polyester including polyester chains. The polyester may be an aliphatic polyester, a semi-aromatic polyester, or an aromatic polyester.
1. A trans-esterified hydroxypropyl lignin (HPL) comprising:
a HPL; and
a polyester including polyester chains.
2. The trans-esterified HPL of claim 1 , wherein the polyester is an aliphatic polyester, a semi-aromatic polyester, or an aromatic polyester.
3. The trans-esterified HPL of claim 1 , wherein an acetate ester of the HPL is used to swap carboxylic acid groups with alcohol oligomer units in the polyester chains.
4. The trans-esterified HPL of claim 1 , wherein polyester oligomer units are covalently-bonded to the HPL while one or more of the polyester chains are shortened and terminated with acetate esters.
5. The trans-esterified HPL of claim 1 , wherein the trans-esterified HPL is represented by a formula R′COOR in which R′ represents the HPL and R represents the polyester.
6. The trans-esterified HPL of claim 1 , wherein transesterification occurs with a replacement of one alcohol group in an ester by another different alcohol group.
7. A trans-esterified hydroxypropyl lignin (HPL) blend comprising:
a HPL;
a polyester including polyester chains; and
one or more additives.
8. The trans-esterified HPL blend of claim 7 , wherein the one or more additives are selected from the group consisting of catalysts, compatibilizers, odor neutralizers, fragrances, and process aids.
9. The trans-esterified HPL blend of claim 7 , further comprising:
a plasticizer.
10. The trans-esterified HPL blend of claim 9 , wherein the plasticizer reduces a glass transition temperature of the trans-esterified HPL.
11. The trans-esterified HPL blend of claim 7 , wherein the trans-esterified HPL blend comprises by weight:
1% to 99% of the HPL;
1% to 99% of the polyster; and
less than 50% of the one or more additives.
12. The trans-esterified HPL blend of claim 9 , wherein the trans-esterified HPL is represented by the formula R′COOR, wherein R′ represents the HPL and R represents the polyester.
13. The trans-esterified HPL blend of claim 9 , wherein an acetate ester of the HPL is used to swap carboxylic acid groups with the alcohol oligomer units in the polyester chains.