Reinforcement Effects of Microfibrillated Cellulose on Chitosan–Polyvinyl Alcohol Nanocomposite Film Properties

Abstract The objective of this research was to analyze the reinforcement effect of microfibrillated cellulose (MFC) on chitosan–polyvinyl alcohol (chitosan-PVA) nanocomposite films in terms of their morphological, physical, chemical, thermal, biological, and mechanical properties. Chitosan-PVA blend films reinforced with MFC filler loadings at 0.5 to 5 percent had smoother, more regular, and more uniform external surface morphology compared with chitosan-PVA reinforced with MFC filler loaded at 7.5 percent. With regard to the physical properties, incorporation of MFC into chitosan-PVA polymer blends reduced nanocomposite film transparency. Furthermore, the films had three different diffraction peaks: crystalline peak, amorphous peak, and small ancillary peak. Compared with the neat chitosan-PVA blend, the addition of MFC to chitosan-PVA polymer blends shifted Fourier-transform infrared spectroscopy peaks at 3,500 to 3,000, 2,918, 1,440, 1,101, and 850 cm−1, indicating a chemical interaction between chitosan-PVA polymer blends and MFC. According to differential scanning calorimetry, thermogravimetric analysis, and differential thermal analysis, the addition of MFC enhanced the thermal stability of chitosan-PVA compared with neat chitosan-PVA composite films. Most nanocomposite films reinforced with MFC had a higher tensile strength than films made from neat chitosan-PVA and chitosan-PVA-MFC 7.5 percent because of percolation formation. However, neither neat chitosan-PVA composite film nor chitosan-PVA-MFC nanocomposite films showed a zone of inhibition or had a zone of inhibition index against Escherichia coli, Staphylococcus aureus, Candida albicans, and Ganoderma sp.