The effect of pre-hydrolysis treatment on properties of novel cellulosic fibre from petioles of betel leaf (Piper betle L.)

In the present study, cellulosic fibres were extracted from petioles of betel leaf (BLP), a by-product of betel leaf industry. The effect of a pre-hydrolysis using HCl on chemical, morphological, structural, and thermal properties of the cellulosic fibre was assessed and compared with the fibre obtained without the hydrolysis treatment. Chemical composition analysis showed that raw BLP contained 33.48%, 12.51%, and 24.89% of cellulose, hemicellulose, and lignin, respectively. Pre-hydrolysis treatment was found to be more effective in the removal of hemicellulose and lignin compared to without pre-hydrolysis treatment and produced cellulosic fibres with cellulose percentage of 81.15%. The individual thread-like microstructure of pre-hydrolysed cellulosic fibres also revealed that, due to the pre-hydrolysis treatment, a significant amount of lignin and inorganic compounds were removed from the raw BLP during delignification and alkali treatments. Pre-hydrolysis treatment also improved the crystallinity index (63.6) and thermal stability (289 degrees C) which were 61.9 and 254 degrees C, respectively, for the cellulose obtained without pre-hydrolysis method. Hence, the cellulosic fibre extracted through pre-hydrolysis treatment can be considered a suitable precursor for nano-cellulose production.