Regenerated cellulose nanofibers fabricated through electrospinning and saponification of cellulose acetate as reinforcement of polylactide composites

Cellulose-acetate nanofibers (CA-NF) and regenerated cellulose nanofibers (RC-NF) were separately compounded as reinforcement materials for enhancement of the mechanical property of polylactide (PLA). PLA has a great potential as an alternative to widely-used plastics such as polystyrene and poly(ethylene terephthalate), which are made from petroleum. PLA is well known for its biodegradability and renewability, but the mechanical property of PLA is not sufficient for industrial applications. In this study, CA-NF were successfully fabricated by electrospinning using 20 wt% cellulose-acetate solution with acetone/N,N-dimethylacetamide (6/4, wt/wt) mixture solvent, and RC-NF were synthesized by subsequent saponification, as reinforcement materials for PLA composites. The Young’s modulus of CA-NF/PLA composites increased linearly from 1670 to 1840 MPa with the increase in the nanofiber concentration to 15 wt%. In contrast, the Young’s modulus of RC-NF/PLA composites rapidly increased to ~ 1840 MPa at the relatively low nanofiber concentration of 5.0 wt%. Above 5.0 wt%, the Young’s modulus became stable and almost constant. RC-NF exhibited better reinforcing efficiency due to the excellent mechanical property of RC-NF, although the interfacial compatibility of RC-NF for PLA matrix was relatively poor as compared with that of CA-NF.