Research on bio-based covalent adaptable networks is popular nowadays in the search for an optimal implementation of thermoset materials and composites in a circular context. Herein, a vanillin derivative is...

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Natural fiber‐reinforced composites are gaining increased interest for their significantly reduced carbon footprint compared to conventional glass or carbon fiber‐based counterparts. In this study, natural fibers are used in a resorcinol‐based epoxy resin that is thermally reshapable at higher temperatures (>180 °C) by using fast exchanging siloxane bonds, catalyzed by 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene. Stress relaxation times of only about 6 s at 220 °C can be reached. A resorcinol‐based epoxy compound is selected because it can be derived from cellulose, opening ways for more sustainable and reshapable composite materials. In a last step of the research, the low viscosity vitrimer formulation (<200 mPa s) is applied to make a flax fiber‐reinforced composite using an industrially relevant vacuum‐assisted resin infusion process. A section of this composite is successfully reshaped, which allows for envisioning a second life for natural fiber‐reinforced composites.

Pressure-sensitive adhesives (PSAs) made from norbornene-functionalized terpenoid-based monomers are reported as a possible alternative to the conventional petrochemically based PSAs. For this, tetrahydrogeranyl, menthyl, and isobornyl norbornenate monomers, with a renewable carbon content up to 72%, are synthesized and copolymerized via ring-opening metathesis polymerization (ROMP) with cyclooctadiene and 5norbornene-2-carboxylic acid. ROMP enables a much faster and controlled polymerization process in comparison to free radical polymerization techniques when targeting high molecular weights and therefore unlocks a potential to design a unique class of PSA materials. The moduli at bonding and debonding frequencies of the obtained PSAs are plotted in the Chang classification system and are used to predict their adhesive performance. Tack and peel measurements indicate that the terpenoid-based norbornenate formulations show similar adhesive properties in comparison to the previously investigated acrylic counterparts.