Characterization and Optimization of Lygodium Circinnatum (Nito) Fiber Properties through Alkali Treatment and Factorial Design

This study characterized Lygodium circinnatum (Nito), a natural fiber native to the Philippines, using a factorial design of experiments to determine the optimal alkali treatment for enhancing its chemical and mechanical properties. Sodium hydroxide (NaOH) was applied at varying concentrations (2%, 8.5%, and 15%) and soaking times, with conditions evaluated using Minitab 18 software. X-ray diffraction (XRD) was used to assess crystallinity index (CI), identifying 2% NaOH and 0.50-hour soaking as the most effective combination, yielding the highest CI. Fourier transform infrared (FTIR) spectroscopy confirmed a reduction in non-cellulosic compounds after treatment. Morphological changes were observed using scanning electron microscopy (SEM), which revealed smoother surfaces and reduced impurities. Mechanical tests showed increased tensile strength and tensile force, although a slight decrease in cross-sectional area was noted, attributed to the loss of surface material. These results demonstrate that mild alkali treatment significantly improves Nito fiber's structural integrity and performance. The study provides a scientific basis for optimizing natural fiber treatment and highlights the potential of Nito fiber in developing sustainable, high-performance materials for use in various engineering and industrial applications, including composites and biodegradable products.