Solid-State Structures and Properties of Lignin Hydrogenolysis Oil Compounds: Shedding a Unique Light on Lignin Valorization.

This article explores the important, and yet often overlooked, solid-state structures of selected bioaromatic compounds commonly found in lignin hydrogenolysis oil, a renewable bio-oil that holds great promise to substitute fossil-based aromatic molecules in a wide range of chemical and material industrial applications. At first, single-crystal X-ray diffraction (SCXRD) was applied to the lignin model compounds, dihydroconiferyl alcohol, propyl guaiacol, and eugenol dimers, in order to elucidate the fundamental molecular interactions present in such small lignin-derived polyols. Then, considering the potential use of these lignin-derived molecules as building blocks for polymer applications, structural analysis was also performed for two chemically modified model compounds, i.

Stabilization of Hybrid Adhesives and Sealants by Thermodynamic Tuning of Molecularly Optimized Lignin Bio-Additives: Small Changes, Big Effects.

The use of lignin as a functional additive has long been a promising topic in both industry and academia, but the development of such systems is still limited by the considerable challenges posed by the incompatibility of lignin with common polymers. Herein, we designed modified silicone (MS) sealants with enhanced UV and thermal stability by incorporating molecularly engineered lignin bio-additives while establishing robust design principles to finely adjust the morphology of such blends by tailoring the molecular structures of lignin fractions. To that end, we first constructed a library of lignin fractions with various molecular weights (obtained by fractionating Kraft lignin and by using a lignin model compound) and with several chemical modifications (acetylation, butyrylation, and silylation).

Aldehyde-Assisted Lignocellulose Fractionation Provides Unique Lignin Oligomers for the Design of Tunable Polyurethane Bioresins.

Thanks to chemical stabilization, aldehyde-assisted fractionation (AAF) of lignocellulosic biomass has recently emerged as a powerful tool for the production of largely uncondensed lignin. Depolymerization of AAF lignin via ether cleavage provides aromatic monomers at near theoretical yields based on ether cleavage and an oligomeric fraction that remains largely unexploited despite its unique material properties. Here, we present an in-depth analytical characterization of AAF oligomers derived from hardwood and softwood in order to elucidate their molecular structures.

Fully Biobased Epoxy Resins from Fatty Acids and Lignin.

The use of renewable resources for plastic production is an imperious need for the reduction of the carbon footprint and the transition towards a circular economy. With that goal in mind, fully biobased epoxy resins have been designed and prepared by combining epoxidized linseed oil, lignin, and a biobased diamine derived from fatty acid dimers. The aromatic structures in lignin provide hardness and strength to an otherwise flexible and breakable epoxy resin.

Thermosetting Polymers from Lignin Model Compounds and Depolymerized Lignins.

Lignin is the most abundant source of renewable ready-made aromatic chemicals for making sustainable polymers. However, the structural heterogeneity, high polydispersity, limited chemical functionality and solubility of most technical lignins makes them challenging to use in developing new bio-based polymers. Recently, greater focus has been given to developing polymers from low molecular weight lignin-based building blocks such as lignin monomers or lignin-derived bio-oils that can be obtained by chemical depolymerization of lignins.

Novel L-DOPA-derived poly(ester amide)s: monomers, polymers, and the first L-DOPA-functionalized biobased adhesive tape.

The synthesis, characterization, and testing of a range of novel bio-inspired L-DOPA-derived poly(ester amide)s is presented, using a widely applicable, straightforward chemistry. A model system is used to study and establish the monomer and polymer synthetic protocols, and to provide a set of optimum reaction conditions. It is further shown that fully biobased L-DOPA-containing adhesive tapes can be fabricated, which are positively evaluated in terms of their adhesive properties.

Interplay between viscoelastic and chemical tunings in fatty-acid-based polyester adhesives: engineering biomass toward functionalized step-growth polymers and soft networks.

This Article describes the synthesis and characterization of renewable self-adhesive coatings with tunable viscoelastic properties and equipped with well-defined amounts of carboxylic acid "sticker" groups with adhesion promoting characteristics. Hydroxyl-ended polyesters with various architectures (linear, branched) were synthesized by melt polycondensation of dimerized fatty acids and fatty diols and then cured with maleic anhydride-modified triglycerides (such as maleinized soybean oil) in the presence of the amidine catalyst 1,8-diazabicyclo[5.4.