Agenda 2030 with the 17 Sustainable Development Goals calls for a range of different measures and actions. One important corner-stone is the availability to sustainable materials, which has intensified the interest for lignocellulosics as they represent an almost inexhaustible source for new materials. This realization has further spurred the interest for biorefinery of biomass as a pathway to isolate new building blocks for renewable materials having the potential to replace fossil-based counterparts.

The aim of this contribution is to discuss some of our latest findings when studying low molecular weight compounds that can be derived from lignocellulosic feedstock, chemically transformed and used for radiation-curable coating applications.

Ferulic acid, or (E)-3-(4-hydroxy-3-methoxyphenyl) prop-2-enoicacid, is a naturally occurring trans-cinnamic acid derivative. It is a component in lignin, found in the plant cell wall bonded to arabinoxylan for instance. Ferulic acid has three functional groups; a phenol, a cinnamoyl double bond, and a carboxylic acid-group, making it a challenging but also useful precursor for material synthesis. We demonstrate that allylation of ferulic acid can attain both mono- and bifunctional monomers that can be used in UV-initiated thiol-ene polymerization. Their reactivity towards trimethylolpropane tris(3-mercaptopropionate) was investigated in detail by photorheology and FT-IR analysis and the crosslinked films were assessed by dynamic mechanical analysis (DMTA) and thermal (DSC) analysis [1].

Turpentine, a pulp industry-derived pine-tree resin, is available in a 300 000 ton scale annually. α-Pinene is the main component in turpentine. It has a bicyclic unsaturated aliphatic structure with rather low reactivity towards conventional polymerization chemistries. However, one of a-pinene ‘s metabolites Sobrerol, which can be formed directly via biotransformation of α-pinene in the fungi Armillaria mella or through aqueous oxidation, constitutes an interesting building block. We demonstrate the further derivatization of Sobrerol to sobrerol-based polymethacrylates (PSobMAs) and their further evaluation in radiation-curable thiol-ene systems [2].

References
[1] L. Pezzana, M. Mousa, E. Malmström., M. Johansson, M. Sangermano, Progress in Organic Coatings 2021, 150, 105986
[2] A. Stamm, M. Tengdelius, B. Schmidt, J. Engström, P. O. Syrén, L. Fogelström, E. Malmström Green Chem., 2019, 21, 2720–273

Alexandros Alexakis

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