High value lignin derivatives, polymers, and copolymers and use thereof in thermoplastic, thermoset, composite, and carbon fiber applications

Abstract

The present disclosure relates to reactive modified lignin, methods of preparing such modified lignin, and materials, such as polymer systems, incorporating the modified lignin. More specifically, the lignin can be modified by selectively masking reactive functional groups such that the material has a modulated reactivity and is thus better suited for incorporation into and/or formation of further materials, such as carbon fibers.

1 - 34 . (canceled) 
     
     
         35 . A method of fractionating lignin, the method comprising:
 combining technical lignin with a first solvent that is suitable to solubilize a portion of the technical lignin and partition the technical lignin into a soluble lignin and an insoluble lignin;   separating the soluble lignin from the insoluble lignin; and   combining the soluble lignin with a second, different solvent that is suitable to fractionate the soluble lignin into two or more fractions with different average molecular weights, different molecular weight distributions, or different functionalities.   
     
     
         36 . The method of  claim 35 , wherein the first solvent comprises a ketone. 
     
     
         37 . The method of  claim 35 , wherein the first solvent comprises acetone. 
     
     
         38 . The method of  claim 35 , wherein the soluble lignin has an average molecular weight that is less than the average molecular weight of the insoluble lignin. 
     
     
         39 . The method of  claim 35 , wherein the second solvent comprises an alkane. 
     
     
         40 . The method of  claim 35 , further comprising modifying at least one of the soluble lignin fractions by covalently incorporating a masking moiety into the structure thereof to form a lignin derivative. 
     
     
         41 . The method of  claim 40 , further comprising polymerizing the lignin derivative. 
     
     
         42 . The method of  claim 41 , wherein the polymerizing comprises copolymerizing the lignin derivative with a comonomer. 
     
     
         43 . The method of  claim 40 , further comprising forming the lignin derivative into a solution or melt blend.