Preparation and properties of aligned poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/cellulose nanowhiskers composites

► Unidirectionally aligned CNW composite was developed by applying electrical field. ► CNW concentration governs the degree of CNW alignment under the field. ► The electric field was effective in aligning CNWs up to 4 wt% CNW concentration. ► Above CNW content of 4 wt%, CNW/PHBV and CNW/CNW interactions restrain CNW mobility. ► The aligned composite showed strong anisotropy.