Chitosan film reinforced with nano-sized chitin whiskers and crosslinked using tannic acid was synthesized by the casting-vaporation method. The mechanical and physicochemical properties of several film samples (consisting of different ratio of chitin and tannic acid) were compared with neat chitosan. Tensile tests show that the addition of chitin improves the nanocomposite films mechanical properties up to 137% compared to neat chitosan, but this is slightly degraded when tannic acid is introduced. However, tannic acid and chitin whisker content greatly reduced moisture content by 294% and water solubility by 13%. Transmission electron microscopy (TEM) and Fourier-transform-infrared spectroscopy (FTIR) were used to investigate the morphology and molecular interaction of film. X-ray diffraction results indicated that the samples with chitin whiskers had a more rigid structure. The addition of tannic acid changed the structure into an anhydrous crystalline conformation when compared to neat chitosan film.
This article presents an analysis of the influence of heat treatment on chitosan nanocomposite film. A series of samples comprising: pure chitosan film, chitosan film embedded with nanocrystalline cellulose (NCC), chitosan film crosslinked with tannic acid and chitosan film with a blend of NCC and tannic acid were heat treated using a convection oven. Fourier-transform-infrared spectroscopy (FTIR) and X-ray diffraction test (XRD) shows the changes in chemical interaction of the heat treated films. The heat treated films show significant improvements in moisture absorption. Tensile strength and Young's Modulus were increased up to 7MPa and 259MPa, respectively when the samples were subjected to heat treatment. For the NCC particles, a transmission electron microscope (TEM) was used to inspect the structural properties of cellulose particle in suspension form.