Tensile and morphological properties of bacterial cellulose nanowhiskers reinforced polylactic acid nanocomposites

Abstract

In this study, bacterial cellulose nanowhiskers (BCNW) reinforced polylactic acid (PLA) nanocomposites were prepared using solution casting technique. The BCNW nanofiller was first isolated from bacterial cellulose (BC) using acid hydrolysis treatment. PLA/BCNW nanocomposites were prepared by the addition of various amounts of BCNW [1-4 parts per hundred parts of polymer (phr)] into PLA matrix. The produced PLA/BCNW nanocomposites were then investigated using Fourier transform infrared (FTIR) spectroscopy, tensile testing and atomic force microscopy (AFM). FTIR spectra analysis indicates that the acid hydrolysis of BC did not altered the chemical structure of isolated BCNW. The tensile testing was revealed that the addition of BCNW into PLA improved the tensile properties of PLA/BCNW nanocomposites. The highest tensile strength of PLA/BCNW was obtained with the addition of 3 phr BCNW which dedicated to approximately 27 MPa. The Young's modulus of the PLA/BCNW nanocomposites increased with increasing the BCNW content due to the stiffening effect of the high modulus BCNW reinforcement. However, elongation at break of PLA/BCNW nanocomposites decreased with the addition of BCNW compared to neat PLA. AFM images of PLA/BCNW nanocomposites indicates the presence of BCNW in PLA/BCNW nanocomposites. The relatively good tensile properties of PLA/BCNW shows its suitability in a wide range of applications such as packaging.