Preparation and characterization of Nano- and Micro fiber Cellulose in the polylactic acid (PLA) based biocomposites

Cellulose nanofiber (CNF) and microcrystalline cellulose (MCC) reinforced polylactic acid (PLA)composites were prepared using a solvent casting method, with the aim of making greennanocomposites. Microstructure, mechanical and thermal properties of the nanocomposites werestudied. Scanning electron microscopy (SEM) micrographs revealed uniform distribution of nano andmicro particles in the polymer matrix at low contents (1 and 3 wt%), but also that a higher content (5wt%) of CNF was easily agglomerated. Mechanical properties of the composites were increasedconsiderably in CNF incorporated composites comparing to MCC filled PLA films. Tensile strength(TS) and elastic modulus (EM) of nanocomposites with MCCs and 1 wt% CNF did not show significantchanges, however elongation percentage (E) increased by more than 60%. The TS, EM and E changedsignificantly for nanocomposites with 3 and 5 wt% CNF. Moreover, nanofiber orientation effectivelyoccurred in the PLA matrix. The reinforcing effect of CNF composition with PLA caused a slightincrease in glass transition and melting temperatures

Keywords:

Cellulose , polylactic acid , nanofiber , microcrystalline , nanocomposite