Improvement of polylactic acid film properties through the addition of cellulose nanocrystals isolated from waste cotton cloth

Cellulose nanocrystals (CNCs) were isolated from waste cotton cloth fibers using a mixed acid hydrolysis method and subsequently used as fillers to reinforce a polylactic acid (PIA) matrix for the construction of high performance and biodegradable PLA/CNC composite films. The morphology, structure, and thermal and mechanical properties of CNCs, PIA, and the composite films were characterized. The length, diameter, and aspect ratio of CNCs ranged from 38 to 424 nm, 2 to 17 nm, and 10-32 respectively. The crystallinity, tensile strength, elasticity modulus, and work-to-break of PLA/CNC composite films were effectively improved by the addition of 0.1 wt% and 0.3 wt% CNCs. However, poor performance parameters were acquired at higher CNC content (0.7 wt%), because the CNCs were not well distributed in the polymer matrix. (C) 2019 Elsevier B.V. All rights reserved.