Investigation of the effects of cellulose nanofiber on the properties of poly(vinyl alcohol) crosslinked by 2,5-furandicarboxylic acid

Bio-based and biodegradable materials have received special interests in recent years as a replacement for petroleum-based plastics. Poly(vinyl alcohol) (PVA), cellulose nanofiber (CNF), and 2,5-furandicarboxylic acid (FDCA) are typical examples among these environmentally friendly molecules. In this study, we investigated the synergistic effects of CNF reinforcement and crosslinking with FDCA on the properties of PVA. The composite films were prepared via a straightforward mechanical-dispersion method, wherein CNF was incorporated into a PVA solution and subsequently crosslinked with FDCA. Comprehensive characterizations, including Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-IR), X-ray diffraction (XRD), Thermal Gravimetric Analysis/Differential Thermal Gravimetric Analysis (TGA/DTGA), Differential Scanning Calorimetry (DSC), tensile testing, and morphological studies, were performed to assess the impact of these modifications. Our findings revealed significant enhancements in the mechanical and thermal properties of the composites. Notably, the tensile strength of the PVA-c-FDCA/CNF composite with 2% CNF reached 37.08 MPa, representing a twofold increase compared to both crosslinked PVA (16.84 MPa) and unmodified PVA (14.57 MPa). TGA/DTGA analysis demonstrated improved thermal stability, with the degradation temperature reaching 371°C, compared to the 298°C observed for PVA. DSC and XRD results indicated a reduction in PVA crystallinity after crosslinking and blending with CNF. Scanning electron microscopy (SEM) images showed good compatibility between PVA and CNF. This study underscores the potential of CNF reinforcement and FDCA crosslinking as a viable strategy to enhance the mechanical properties of PVA-based materials.