Surface modification of Himalayan nettle fibre with chemical treatments for potential reinforcement in polymer composites
摘要
Among different natural fibres, Himalayan nettle is gaining importance as reinforcement, an alternative to synthetic fibre, for polymer composite synthesis due to its wide availability, low price, and sustainable production. In this study, untreated (raw) and chemically treated nettle fibres were characterized by standard testing methods to find the best chemical type and concentration for surface modification, as there is not a single chemical treatment equally effective for all kinds of natural fibre. Alkali (3 and 5%), silane (1 and 3%), and hydrogen peroxide (3 and 5%) solutions were used for chemical treatment. The fibres were characterized by compositional analysis, XRD, FTIR, SEM, AFM, single fibre mechanical strength, and physical properties like diameter and fibre density. Among all chemical treatments, 3% alkali–treated fibre showed the maximum tensile strength (571.06 MPa), high cellulose content (83.8 wt%), high crystallinity index (82.55%), lower crystallite size (11.25 nm), highest roughness parameters (788 nm Rmax), lower fibre width, lowest microfibril angle, and higher elongation at break. The tensile strength of 571.06 MPa observed for 3% alkali–treated fibre was significantly high and suitable for reinforcement with polymer matrices. The 3% alkali–treated fibre exhibited the lowest weight loss (61.0%) in 2nd stage thermal degradation and the maximum residual weight (24.31%) at 800°C, indicating improved thermal stability than the other studied fibre samples. Thus, this study justifies the suitability of the 3% alkali treatment for surface modification of the nettle fibre to be utilized in polymer composite synthesis.