Aging Behaviour Assessment of Cellulosic Fibres in Alkaline Media: A Green Technology Approach in Construction Materials

With the increasing demand for buildings, the utilisation of green materials represents a novel approach toward achieving sustainable development goals. Cellulose-based materials, such as jute, exemplify eco-friendly substances for civil engineering applications. The present study aims at studying the aging behavior of jute fibers in an alkaline environment. For this purpose, three alkali environments (NaOH, KOH, Ca(OH)2) with three different concentrations were selected. Samples were treated at three different periods (7d, 14d, and 28d) to assess the impact of treatment on the fiber properties. This study introduces a pioneering concept of the alkali treatment of jute-based fibres to evaluate tensile strength and weight loss, marking the first of its kind. This approach incorporates various characterisation techniques, including Differential Scanning Calorimetry (DSC), Thermo-Gravimetric Analysis (TGA), and Scanning Electron Microscopy (SEM) to assess the treatment process. In our experimental procedures, we evaluated key parameters such as the type of alkali, alkali concentration, and curing time for their influence on tensile strength. Subsequently, we applied Response Surface Methodology (RSM) in conjunction with bagging techniques to develop mathematical models based on the acquired data. Results demonstrated varied tensile strengths based on alkali type, concentration, and treatment duration. Fibres treated with 15 g/L concentration of NaOH exhibited an increase in tensile strength from 7 days (79.66 MPa) to 28 days (225.05 MPa). The highest tensile strength of jute fibres treated with KOH was observed with 15 g/L concentration at 14 days (237.58 MPa). For Ca(OH)₂ treatments, the highest tensile strength was observed with 30 g/L concentration at 14 days (111.28 MPa). It was also observed that prolonged exposure to very high alkali concentrations could adversely affect the tensile strength, as observed in the case of 30 g/L concentration of NaOH at 28 days (84.73 MPa). Among the various alkali materials tested, NaOH and KOH demonstrated greater effectiveness compared to Ca(OH)2. According to RSM analysis, the time of sample curing was found to be the most significant factor in tensile strength, with a P-value of 0.009. On average, the tensile strength changes by 54%, 52%, and 35% for NaOH, KOH, and Ca(OH)₂, respectively, when the curing time shifts from 7 days to 28 days.