Morphological, Chemical, and Mechanical Characterization of Untreated and Mercerized Lignocellulosic Fibers

The exponential increase in carbon emissions has prompted a deviation from natural fibers as an alternative to synthetic materials. Bamboo culms, pineapple leaves, and coconut husks contain lignocellulosic fibers that can be used in biocomposite and geotextile applications. Hence, this study aimed to determine the surface morphology, mean diameter, porosity, chemical composition, and tensile strength of untreated and alkalized fibers, with 6% sodium hydroxide used for treatment. Results revealed that mercerization enhanced the fibers’ adhesion and restructured the fractured fragments of the fibers’ microstructure. Moreover, the FTIR results showed an improved cellulose content in the treated lignocellulosic fibers. Mercerized bamboo fibers contain the highest cellulose content at a critical peak of 3389 cm-1, while treated coconut fibers yield the lowest cellulose content at an absorption peak of 3339 cm-1. Conversely, treated bamboo fibers yield the highest tensile strength of 23.6897 MPa (a 90.43% increase), while treated coconut fibers yield the lowest tensile strength of 2.0389 MPa (a 10.87% increase). In conclusion, the mercerization of fibers improves surface morphology, cellular composition, and mechanical strength.