Ductile nanocellulose-based films with high stretchability and tear resistance

•Nanofibrillated cellulose–cationic hydroxyethylcellulose–glycerol films prepared.•Films cast from aqueous solution.•Poly(propylene carbonate) used as coating to enhance water stability.•High elongation values; amongst the highest for high cellulose content films.•Toughness and water stability also enhanced.