Strategies for the Conversion of Lignin to High-Value Polymeric Materials: Review and Perspective

Abstract

The majority of commodity plastics and materials are derived from petroleum-based chemicals, illustrating the strong dependence on products derived from non-renewable energy sources. As the most accessible, renewable form of carbon (in comparison to CO2), lignocellulosic biomass (defined as organic matter available on a renewable basis) has been acknowledged as the most logical carbon-based feedstock for a variety of materials such as biofuels and chemicals. This Review focuses on methods developed to synthesize polymers derived from lignin, monolignols, and lignin-derived chemicals. Major topics include the structure and processing of lignocellulosic biomass to lignin, polymers utilizing lignin as a macromonomer, synthesis of monomers and polymers from monolignols, and polymers from lignin-derived chemicals, such as vanillin.

Complete lignocellulose conversion with integrated catalyst recycling yielding valuable aromatics and fuels

“…8a, Supplementary Note 13) 42,43 . Firstly, some of the compounds synthetized here have already found applications as polymer building blocks.…”

“…For instance, compound 7 was used to synthesize a series of well-defined bio-based poly(vinylguaiacols) with phenolic functions 44 . 6 is a building block for the synthesis of epoxy resins, polyesters or polyurethanes 42,43 . Stilbene (7S) serves as starting material for bisphenol-A analogues 42 , while 3G and 6 can also be used as precursors for synthesis of sustainable bisphenols 42,43 .…”

“…Secondly, besides existing applications, the building blocks described here will open new avenues toward the development of new, emerging renewable polymeric materials as potential replacements for petroleum-derived plastics (Supplementary Note 14) 42,43 . Compound 7 may serve as a building block in various glycopolymers used for drug or gene delivery systems 45 .…”

“…Compound 7 may serve as a building block in various glycopolymers used for drug or gene delivery systems 45 . Due to the similar structure to vanillin alcohol, 1G can also be used for synthesis of bisphenols, epoxy resins, polyesters or polyurethanes 43 . Building blocks 1G, 4, 5, 6, 12a-c and 13 can potentially serve as precursors for new polyesters or polyamides as sole components or by co-condensation with bio-derived diols or dicarboxylic acids 43 .…”

“…Due to the similar structure to vanillin alcohol, 1G can also be used for synthesis of bisphenols, epoxy resins, polyesters or polyurethanes 43 . Building blocks 1G, 4, 5, 6, 12a-c and 13 can potentially serve as precursors for new polyesters or polyamides as sole components or by co-condensation with bio-derived diols or dicarboxylic acids 43 . On catalytic demethylation, 5 is an attractive monomer for the synthesis of advanced biomimetic glues 46 .…”