Abstract

This study investigates the use of poly(vinylidene fluoride-co-hexafluoropropylene) [P(VDF-HFP)] as a transparent, water-repellent, and antifungal coating for Krajood (Lepironia articulata) products—traditional natural fibers widely used in Thailand. Coatings with P(VDF-HFP) were formulated at concentrations ranging from 2.5 to 25% and applied via a solution casting technique. The surface, thermal, mechanical, and biological properties of the coated samples were systematically characterized and compared to uncoated and lacquer-coated controls using Fourier-transform infrared spectroscopy (FTIR), water contact angle (WCA) measurements, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and tensile testing. Results indicate that the 15% P(VDF-HFP) coating provides the most optimal performance, offering high hydrophobicity (WCA = 124.2°), enhanced tensile strength (112.26 MPa), superior thermal resistance (onset degradation at 241.9 °C), and significant fungal inactivation over a 30-day incubation period. The formation of a microporous surface structure, due to slow solvent evaporation, was found to play a key role in improving both water repellency and fungal resistance. These findings demonstrate the potential of P(VDF-HFP) coatings in extending the lifespan and functionality of natural fiber products, providing a sustainable alternative for moisture-prone applications.