Preparation of fluorine- and nanoparticle-free superwetting polybenzoxazine/cellulose composites for efficient oil/water separations

•The furan-based polybenzoxazine (Fu-PBZ) has been successfully prepared.•The cured Fu-PBZ possessed extremely high Tg (295 °C), and low surface free energy (13.5 mJ/m2).•Fu-PBZ@CF and Fu-PBZ@FP were prepared by a non-solvent-induced phase inversion method.•Fu-PBZ@CF and Fu-PBZ@FP both possessed superhydrophobicity and superoleophilicity.•Fu-PBZ@CF and Fu-PBZ@FP exhibited excellent separation performance for oil/water mixtures and emulsions, respectively.