Nanocomposite Fibers Electrospun from Poly(lactic acid)/Cellulose Nanocrystals

PLA/cellulose nanocomposite fibers were electrospun at elevated temperatures from solutions of Poly(lactic acid) (PLA) in N,N-dimethylformamide (DMF) containing suspended cellulose nanocrystals. Electrospinning conditions were optimized to form PLA/cellulose nanocomposite fibers with uniform diameters and smooth morphology at cellulose nanocrystal loadings of 0%, 1% w/w and 10% w/w (on the weight of PLA). Average fiber diameter decreased with the addition of cellulose nanocrystals. Surface elemental composition analysis confirmed the presence of cellulose nanocrystals at the surface of PLA fibers and the quantity of cellulose available at the surface was enriched compared to the bulk composition. Cellulose nanocrystals acted as nucleation sites during the electrospinning process resulting in increased crystallinity of electrospun PLA nanocomposite fibers. The strength of the electrospun non-woven fabrics was improved by the incorporation of cellulose nanocrystals into PLA as a result of increased crystallinity and decreased fiber diameter. Elongation of electrospun non-woven fabrics decreased at higher cellulose nanocrystal loadings indicating a lack of adhesion between cellulose nanocrystals and PLA in the fibers.