Impact of the processing method on the properties of castor oil/cellulose acetate polyurethane adhesives for bonding wood

During the last decades, replacement of traditionally petro-based raw materials by eco-friendly substances in polyurethane production has become a great challenge. The synthesis polyurethanes is mainly conducted means selective reaction between active isocyanate and hydroxyl groups, yielding characteristic segmented chemical structure. In this study, traditional solvent-based polycondensation for bio-based adhesives, involving first cellulose acetate modification with 1,6-hexamethylene diisocyanate subsequent crosslinking castor oil, was evaluated compared simpler solvent-free single-step protocol. impact preparation procedure reagent proportions, on structure, thermo-rheological behaviour ultimate adhesion performance were evaluated. rheological response these bio-inspired also to those found some commercial adhesives. This research highlights reinforcing stabilizing effect bio-polyurethane performance. Particularly, inclusion into adhesive manufacture allowed reduction maximum curing time under room conditions almost one week, while higher thermal stability fourfold increase elastic modulus comparison acetate-free counterpart. Moreover, proposed synthetic route enhanced microphase mixing ensuing polyurethanes, exhibiting an comparable considered benchmarks, but failure occurring primarily within substrate material – preferred locus failure.