Extraction and physicochemical–thermal characterization of leaf mucilage from Butea monosperma with potential relevance to biodegradable materials

Abstract

Background: Growing concerns over the persistence of petroleum-based plastics have renewed interest in plant-derived polysaccharides as sustainable material precursors. Methodology: In this work, mucilage extracted from Butea monosperma leaves was examined using comprehensive physicochemical, rheological, thermal, morphological, and solid-state characterisation to assess its properties. Result and Discussion: The extraction process yielded 10.58±0.42% (n=3) mucilage. Powder flow analysis indicated acceptable handling characteristics, with an angle of repose of 29.17±1.34°, Carr’s index of 17.18±1.02%, and a Hausner ratio of 1.20±0.04. Aqueous dispersions (1.5% w/v) displayed shear-dependent viscosity over the range of 10–150 rpm, consistent with pseudoplastic flow behaviour. Dynamic light scattering measurements showed a mean hydrodynamic diameter of approximately 1085 nm, while the zeta potential value of –11.6 mV suggested moderate electrostatic stability of the dispersion. FTIR spectra confirmed the polysaccharide nature of the mucilage through characteristic hydroxyl, aliphatic, carbonyl, and glycosidic bands. X-ray diffraction revealed a predominantly amorphous structure with limited semi-crystalline domains. Thermal analysis showed minor mass loss below 190°C, followed by a principal degradation stage between 226 and 322 °C with an overall mass loss of ~61.9%, while DSC analysis identified multiple endothermic transitions, including a major event at 275.99°C. Conclusion: Collectively, these findings establish reproducible yield, non-Newtonian rheology, moderate thermal stability, and an amorphous solid-state profile for Butea monosperma leaf mucilage. The observed properties suggest their potential relevance as a plant-based biopolymer and merit further investigation through material fabrication, mechanical and barrier testing, biodegradation assessment, and safety evaluation.