Mechanical properties and in vitro degradation of electrospun bio-nanocomposite mats from PLA and cellulose nanocrystals

Abstract

Fibrous bio-nanocomposite mats consisting of cellulose nanocrystals (CNCs) and poly(lactic acid) (PLA) were electrospun from a solvent mixture consisting of N,N'-dimethylformamide and chloroform at room temperature. Morphological, mechanical and thermal properties, as well as in vitro degradation of nanocomposite mats were characterized as a function of material composition. Average diameter of the electrospun fibers decreased with increased CNC-loading level. Thermal stability, and tensile strength and modulus of nanocomposite mats were effectively improved by the addition of CNCs up to the 5 wt% level. The reinforcement of CNCs on electrospun mats was illustrated by the observation of SEM-based morphologies on the tensile fracturing process of nanocomposite mats. At the CNC content of 5 wt%, the maximum tensile stress and Young's modulus of the nanocomposite mats increased by 5 and 22 folds than those of neat PLA mats, respectively. Moreover, compared with neat PLA mats, the nanocomposite mats, especially at high CNC-loading levels, degraded more rapidly in phosphate-buffered saline solution.