Compositions including esterified lignin and poly (lactic acid) and carbon fibers produced therefrom

Abstract

The present invention relates to compositions comprising esterified lignin and poly(lactic acid). In various embodiments, the present invention provides fibers comprising the esterified lignin and poly(lactic acid) blend, carbon fibers made therefrom, and methods of making the fiber and the carbon fibers.

1 . (canceled) 
     
     
         2 . A composition comprising:
 lignin comprising at least one esterified —OH group, wherein
 the esterified —OH group has the structure —OC(O)R, and 
 each R is independently a C 1 -C 30  hydrocarbyl group; and 
   poly(lactic acid).   
     
     
         3 . The composition of  claim 2 , wherein the weight ratio of the esterified lignin to the poly(lactic acid) is about 1:1-999:1 by weight. 
     
     
         4 . The composition of  claim 2 , wherein the weight ratio of the esterified lignin to the poly(lactic acid) is about 1.9:1-9:1 by weight. 
     
     
         5 . The composition of  claim 2 , wherein the esterified lignin is derived from at least one of softwood lignin, hardwood lignin, lignin obtained from a sulphite pulping process, lignin obtained from a soda pulping process, lignin obtained from an organosolv process, lignin obtained from a kraft process, and lignin extracted using an ionic liquid. 
     
     
         6 . The composition of  claim 2 , wherein about 50-100% of the —OH groups on the lignin are esterified. 
     
     
         7 . The composition of  claim 2 , wherein about 100% of the —OH groups on the lignin are esterified. 
     
     
         8 . The composition of  claim 2 , wherein each R group is a C 1 -C 30  alkyl group. 
     
     
         9 . The composition of  claim 2 , wherein each R group is a propyl group. 
     
     
         10 . The composition of  claim 2 , wherein the composition has a glass transition temperature of about 40-70° C. 
     
     
         11 . The composition of  claim 2 , wherein the composition has a melting temperature of about 150-170° C. 
     
     
         12 . The composition of  claim 2 , wherein the esterified lignin and the PLA are not fully miscible. 
     
     
         13 . The composition of  claim 2 , wherein the composition has a maximum thermal decomposition temperature of about 330-395° C. 
     
     
         14 . A fiber comprising the blend of  claim 2 . 
     
     
         15 . The fiber of  claim 14 , wherein the fiber has a diameter of about 1-300 μm. 
     
     
         16 . The fiber of  claim 14 , wherein the fiber has a tensile modulus of about 500 to about 4000 MPa. 
     
     
         17 . The fiber of  claim 14 , wherein the esterified lignin and poly(lactic acid) do not exhibit macrophase separation. 
     
     
         18 . The fiber of  claim 14 , wherein the esterified lignin and poly(lactic acid) have at least some microphase separation. 
     
     
         19 . The fiber of  claim 14 , comprising a plurality of smaller fibers within a larger fiber, wherein the plurality of smaller fibers substantially align with the length of the larger fiber. 
     
     
         20 . The fiber of  claim 19 , wherein each of the plurality of smaller fibers independently have a diameter that is about 1/10 to about 1/1,000,000 the diameter of the larger fiber. 
     
     
         21 . The fiber of  claim 19 , wherein each of the plurality of smaller fibers independently has a diameter of less than about 1-2 μm.