Bio-Based Polybenzoxazine-Cellulose Grafted Films: Material Fabrication and Properties

Despite the fact that amino cellulose (AC) is biodegradable, biocompatible, and has excellent film-forming properties, AC films have poor mechanical properties and are not thermally stable. An AC-based composite film prepared from AC and curcumin-stearylamine based benzoxazine (C-st) is reported in order to improve its performance and promote its application. As starting materials, C-st and AC were used to produce a C-st/AC composite film possessing a synergistic property through chemical cross-linking and hydrogen bonds. Two salient features with respect to the curing behavior were obtained. Firstly, the onset of curing was reduced to 163 °C when the benzoxazine monomer was synthesized from fully bio-based precursors (such as curcumin and stearylamine). Secondly, a synergistic effect in curing behavior was obtained by mixing C-st with AC. As a result of tensile tests and thermal analysis, the poly(C-st) benefited the composite films with pronounced mechanical and thermal properties, even at elevated temperatures. There was a 2.5-fold increase in tensile strength compared to the AC film, indicating that the composite films have the potential to be used for functional purposes. These poly(C-st)/AC films with improved mechanical and thermal properties have the ability to replace naturally occurring polymer films in film-related applications.