Comparison of alkali concentration for obtaining fine Musa Sapientum (banana) fibers to enhance potential applications

The objective of the present research was to investigate the efficiency of alkali treatment on obtaining fine banana fibers. The fibers were exposed to alkali aqueous solutions at different concentrations changing from 5 to 20 wt%. The acting mechanism of the alkali treatment is removing of non-cellulosic constituents and separating the fiber bundle into smaller elementary single fibers. The efficiency of the alkali treatments was analyzed with the help of optical observations, fiber diameter measurement, single fiber tensile test and determination of pectin component. Chemical, crystalline, thermal and morphological properties of the fibers were examined by FTIR, XRD, TGA and SEM, respectively. FTIR analyses proved the removal of non-cellulosic components such as hemicellulose and lignin after alkali treatment. Fiber diameter decreased with increasing concentration of alkali treatment. Tensile properties and crystallinity index are correlated with alkali concentration. However, cellulose structure of the banana fiber was altered at mild alkali treatments. Microscopic observations revealed the appearance of single elementary fibers from the fiber bundle of the banana. These experimental findings suggested that alkali treatment can play promising role to prepare lignocellulosic fibers for textile applications.