Thermo-physical characterization of sesame stalk fibers for future use in bio-composite materials

Abstract

In response to the challenges posed by climate change and growing urbanization, the construction sector is under increasing pressure to reduce its environmental footprint. Plant-based insulation materials offer a sustainable alternative to conventional solutions due to their low cost, renewability, and carbon-neutral life cycle. Among these, sesame (Sesamum indicum L.) is widely cultivated in Senegal, yet its fibrous by-products are largely underutilized. This study investigates the thermo-physical properties of sesame fibers to assess their suitability for use in eco-friendly building insulation materials. Physical characterization included particle size distribution, moisture content, water absorption, solubility, bulk density, and sorption–desorption behavior. Thermal performance was evaluated through thermal conductivity and effusivity measurements using the hot-wire method. Results show that sesame fibers are highly porous, with an average bulk density of 101.13 kg/m³, and exhibit strong hydrophilic behavior, absorbing up to ∼300% of their dry mass. Their moisture content ranged from 11% to 12%, and solubility was minimal (<0.05%). Thermal conductivity values ranged from 0.048 to 0.057 W.m⁻¹.K⁻¹, increasing with bulk density. These values are comparable to those of other natural insulators such as hemp and Typha, based on the literature. The findings confirm the potential of sesame fibers as a low-cost, locally available, and environmentally sustainable alternative for the production of bio-composites materials.