Effects of chemical treatments on morphological, physical and chemical properties of okra bast fibers

Abstract

In this study, bast fibers have been obtained from okra (Abelmoschus esculentus) plant stems via biological degumming process. The obtained fibers were subjected to some textile pretreatment processes such as scouring, alkalizing, oxygen bleaching and chlorine bleaching which are also utilized in cellulose nanoparticle production. Effects of these processes on their physical and chemical characteristics have been investigated and statistically analyzed. Treatments have been found to statistically affect physical properties of the fibers. They led to decrease in fiber linear density but increase in moisture content and water absorption capacity. Linear density reduction took place by fibrillation and elimination of impurities. Fibrillation has been evidenced by microscopy images. Prolonged submerging resulted in increment in water absorption. FT-IR spectra, SEM images and mass loss analysis present evidence for removal of lignin, hemicelluloses and vaxes upon chemical treatments. The ranges of the linear density, moisture content and water absorption of okra bast fibers are 6.3-20.1 tex, 2.9-6.0%, and 5.80 g/g to 11.8 g/g, respectively. Properties of okra bast fibers show similarities to conventional bast fibers such as flax, hemp and jute.