Multi-response modeling and optimization of mechanical properties of extracted date palm fibers using Box–Behnken design

Date palm fibers (DPFs) are the most promising lignocellulosic source because of their low-cost, excellent tensile properties , and high abrasion resistance . This study focuses on optimizing of physicochemical and tensile characteristics of natural lignocellulosic fibers extracted from local DPFs in Iran. The KOH alkalization process of DPFs was evaluated using the response surface methodology (RSM). RSM was used to investigate the influence of three parameters on the physicochemical characteristics of DPFs. A surface modification method was operated on neat DPFs by alkali treatment with various KOH concentrations: 0.5, 1, and 1.5 mol/L, different times: 30, 90, and 150 min, and various temperatures: 30, 60, and 90 °C. The statistical models specified that KOH concentration was the main parameter changing the performance of DPFs. The optimum conditions that led to the highest mechanical characteristics were a treatment temperature of 30°C, a treatment time of 86.2 min, and a KOH concentration of 1.5 mol/L. The tensile strength and tensile modulus under the above conditions were obtained at 523.71 ± 9.60 MPa and 16.89 ± 1.22 GPa, respectively. KOH material was preferred to be used due to its larger molecular size than NaOH. This exclusivity causes less failure to the DPFs structure during the alkali treatment . • The KOH alkalization of DPFs was investigated by different KOH concentrations, immersion times, and temperatures. • Response surface methodology was used for modeling and optimization of mechanical properties of DPFs. • The optimized DPFs have the highest strength of 523.71 ± 9.60 MPa and highest modulus of 16.89 ± 1.22 GPa.