Title
A study of morphological thermal mechanical and barrier properties of PLA based biocomposites prepared by micro and nano sized cellulosic fibers
Authors
ALI ABDULKHANI JABER HOSSEINZADEH SAMANEH KARIMI SAEED DADASHI and MOHAMMAD MOUSAV

Published Volume 49 Issue 7-8 July-August
Keywords cellulose, polylactic acid, nanofiber, microcrystalline cellulose, nanocomposite

Abstract
Polylactic acid (PLA) nanocomposites with embedded acetylated cellulose nanofiber (CNF-Ac) and microcrystalline cellulose (MCC) were prepared using a solvent casting procedure. The microstructure, topography, barrier, mechanical and thermal properties of the composites were evaluated. Scanning electron microscopy micrographs clearly reveal uniform distribution of the reinforcing particles in the polymer at low loading levels (1 and 3 wt%), while higher content (5 wt%) of CNF-Ac and MCC contributed to easy aggregation within the matrix. The mechanical properties of the CNF-Ac incorporated composites were substantially increased in comparison with MCC filled PLA films. Comparing with nanocomposites, water vapor permeability of the MCC composites was increased at low content of MCC in the films. The tensile strength and tensile modulus of the composites with different loadings of MCC and 1 wt% CNF-Ac did not show any significant change. However, the strain of nano and micro filled composites was increased by more than 60% and 35%, respectively. The tensile strength, tensile modulus and strain were significantly increased for nanocomposites with 3 and 5 wt% CNF-Ac. Glass transition temperature of PLA was increased as a result of the incorporation with nanocellulose, while it was decreased by the incorporation of the films with microcrystalline cellulose.