Recent Advances in the targeted Functionalization of Lignin

A targeted use and functionalisation of lignin obtained within biomass refinery processes is still to be improved in order to obtain a wider variety of possibilities that can give rise to the application of lignin in high value applications. The oxidative functionalisation, and thus valorisation of lignin, is a very promising way to go, since it holds the possibilities to yield highly functionalised, monomeric or oligomeric products that can serve as starting materials for further valorisation in the chemical and pharmaceutical industries. Gaining a profound knowledge about the structure of lignin, being able to analyse structural features, separate lignins according to structural features, and understanding the mechanisms that guide the reactions leading to oxidative derivatisation and enzymatic functionalisation of lignin samples from different renewable sources are key requirements for developing protocols for a defined oxidative valorisation of lignin. In our presentation, we wish to revisit, and set into context, some important achievements in the field of oxidatively upgrading lignin and add new findings concerning the use of non-classical lingo-cellulosic enzymes in lignin valorisation protocols. Apart from enzymatic transformations, we will present the formation of a wide variety of functional lignins via a simple strategy. This strategy is applicable also to the formation of block-copolymers in which lignin is covalently linked to both other natural polymers and synthetic polymers