Comparison of polyvinyl alcohol films reinforced with cellulose nanofibers derived from oil palm by impregnating and casting methods.

Cellulose nanofibers (CNFs) derived from oil palm trees were utilized to reinforce polyvinyl alcohol (PVA) films by either casting or impregnating. CNFs derived from trunks of the oil palm tree were dispersed well in a PVA film by the casting method. Using the impregnating method, however, a sandwich construction with CNFs and PVA was obtained, which was confirmed using attenuated total reflectance Fourier transform infrared spectroscopy. The thermal stability, tensile strength, and Young's moduli of the PVA/CNF nanocomposite films were increased by compounding CNFs at different concentrations using both the casting and impregnating methods. However, the impregnated nanocomposite films showed higher thermal melting temperature and higher tensile toughness than those obtained by the casting method. No obvious differences appeared in the X-ray diffraction patterns or thermal decomposition behavior between the impregnated and cast nanocomposite films. In addition, adding CNFs was confirmed to increase the crystallinity of PVA.