Functional lignin, and its use in producing blends, copolymers, and self-healing elastomers

Abstract

A composition comprising lignin compounds possessing 8-30 (or 5-15 or 8-12) phenyl rings interconnected by ether and alkylene linkages and containing hydroxy and/or methoxy groups attached to said phenyl rings, wherein said composition possesses a glass transition temperature of 80-100° C. (or 95-98° C.) and a degree of substitution (DS) of carboxylic acid groups per phenyl ring of at least 0.5 and a DS of methoxy groups per phenyl ring of no more than 1.2, 1.1, or 1.0, wherein at least 90 wt % of said lignin compounds has a molecular weight within a range of 500-5000 g/mol, 1500-3000 g/mol, or 2000-2500 g/mol and/or wherein the molecular weight distribution of the lignin compounds is characterized by a polydispersity index of 1.0-1.5, 1.0-1.4, or 1.0-1.3, and wherein other lignin compounds not possessing the above characteristics are not present. Methods for producing the lignin extract and lignin copolymers and blends produced therefrom are also described.