<p>This study aims to evaluate the effect of an eco-friendly and cost-effective surface treatment method based on the use of commercial sodium bicarbonate on the physicochemical, morphological, and tensile properties of jute yarns. Specifically, raw jute yarns were treated with sodium bicarbonate (NaHCO₃) solutions of different concentrations (5%, 10%, 15%, 20%, 25%, and 30%) for various treatment durations (1, 3, 6, 12, 24, and 48 h) at room temperature. The modifications of jute yarns treated with a 25% concentration at different treatment durations were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and helium pycnometer. The mechanical characterization of untreated and NaHCO₃-treated jute yarns was performed through uniaxial static tensile tests. The results of the tensile properties (tensile strength <i>σ</i>, elastic strain <i>ɛ</i> and Young’s modulus <i>E</i>) of the jute bundles showed significant variability, which is typical for natural fibers. Therefore, a statistical study based on response surface methodology (RSM), analysis of variance (ANOVA), and response optimization using the desirability function approach was employed. The SEM micrographs of the longitudinal topographic surface of the jute yarns after chemical treatment with sodium bicarbonate at various times treatment indicated that the removed the waxy layer and impurities from surface and formed a roughened surface and increase the Crystallinity Index (CrI) and Crystalline Size (CrS) of the jute yarns. In addition, the results indicated that at a NaHCO₃ concentration of 25% and a treatment duration of 12.97 h, the tensile strength, elastic strain, and Young’s modulus reached optimal values of 38.49 MPa, 4.009%, and 1.311 GPa, respectively.</p> Graphical abstract <p></p>