Optically transparent laminated acrylic composites reinforced with mercerised bacterial cellulose nanopaper

Bacterial cellulose (BC) nanopaper is an important material structure for the production of high-performance cellulose nanocomposites. Here, we report the mercerisation of BC nanofibrils as a route to produce ductile BC nanopaper. Mercerised BC nanopaper was found to possess a ductile response under uniaxial tension, albeit with lower tensile modulus and strength compared to neat BC nanopaper due to the presence of large fraction of disordered cellulose. The impregnation of (mercerised) BC nanopaper with an acrylated urethane resin, followed by lamination with impact-modified acrylic produces optically transparent BC/acrylic composites. At a BC loading of only 8 wt%, the mercerised BC/acrylic composite possessed a flatwise and edgewise Charpy impact strength of 19.0 kJ m(-2) and 19.5 kJ m(-2), respectively; a 62% and 22% increase over monolithic acrylic. The influence of different alkaline treatments on the morphology, crystallography, mechanical and optical properties of the BC nanopaper, as well as the BC/acrylic composites are juxtaposed in this work.