Oxyalkylated lignin polyols, related compositions, and related methods

A method for forming an oxyalkylated lignin polyol, the method comprising:

• providing a reaction mixture comprising:
• a cyclic alkyl carbonate,
• a lignin, and
• an oxyalkylation catalyst;
• performing an oxyalkylation reaction in the reaction mixture to react the cyclic alkyl carbonate with the lignin, thereby forming an oxyalkylated lignin polyol reaction product;
• and
• performing a transesterification reaction at reduced pressure, thereby reacting (i) oxyalkylated lignin polyol with (ii) one or both of lignin and oxyalkylated lignin polyol, thereby forming a diol corresponding to the cyclic alkyl carbonate.

A method for forming an oxyalkylated lignin polyol, the method comprising:

• providing a reaction mixture comprising:
• a cyclic alkyl carbonate,
• a lignin, and
• an oxyalkylation catalyst;
• and
• performing an oxyalkylation reaction in the reaction mixture to react the cyclic alkyl carbonate with the lignin, thereby forming an oxyalkylated lignin polyol reaction product;
• wherein the lignin, prior to incorporation into the reaction mixture, has at least one of the following properties:
• a molecular weight in a range of 500 to 10000;
• a polydispersity in a range of 1.2 to 5;
• an aliphatic hydroxyl content in a range of 0.5 to 7 mmol/g;
• a phenol hydroxyl content in a range of 1 to 7 mmol/g;
• a carboxylic hydroxyl content less than 1 mmol/g;
• and
• a total hydroxyl content in a range of 2 to 10 mmol/g.

A method for forming an oxyalkylated lignin polyol, the method comprising:

• providing a reaction mixture comprising:
• a dialkyl carbonate,
• a polyol reactive co-solvent, and
• an oxyalkylation catalyst;
• performing a first transesterification reaction, thereby reacting (i) the dialkyl carbonate with (ii) the polyol, thereby forming a carbonate-terminated derivative of the polyol and an alcohol corresponding to the dialkyl carbonate;
• and
• performing a second transesterification reaction with a lignin, thereby reacting (i) the carbonate-terminated derivative of the polyol with (ii) the lignin, thereby forming a polycarbonate oxyalkylated lignin polyol.

A method for forming an oxyalkylated lignin polyol, the method comprising:

• providing a reaction mixture comprising:
• a cyclic alkyl carbonate,
• a lignin, and
• an oxyalkylation catalyst;
• performing an oxyalkylation reaction in the reaction mixture to react the cyclic alkyl carbonate with the lignin, thereby forming an oxyalkylated lignin polyol reaction product with unreacted excess cyclic alkyl carbonate;
• performing a ring-opening reaction with water, thereby reacting (i) the water with (ii) the unreacted excess cyclic alkyl carbonate, thereby forming a polycarbonate alkylene polyol.