Preparation and Properties of Silane-Modified Cellulose Nanofiber and Its Blended Bio-Polyurethane Based Composites Film

Abstract

This study focuses on enhancing nanocellulose dispersion in bio-polyurethane (B-PU) films through silane modification using methyltrimethoxysilane (MTMS). Analyzing wetting, chemical, thermal, morphological, and dispersion properties of modified and unmodified cellulose nanofiber (CNF), the study demonstrates controlled MTMS conjugation, controlling diameter between 50–100 nm. Zeta potential values indicate improved Si-CNF dispersion stability in dimethylformamide. Scanning electron microscopy confirms enhanced dispersion in B-PU composites. Tensile strength increases by 23.52% at 1–2% Si-CNF but decreases (23.80–40.47%) at 4–8%. Si-CNF increases elongation by up to 4%, decreasing slightly at 8%. X-ray diffraction shows B-PU/Si-CNF 1wt.% has the highest crystallinity. Composite films exhibit improved thermal stability. This interaction offers a unique way to enhance Si-CNF and B-PU compatibility, promising applications in furniture coating, biomedical, and food packaging industries.