Characterization of raw and alkali-treated mulberry fibers as potential reinforcement in polymer composites

Abstract

In this research the fibers were extracted from mulberry plant and treated with various concentrations of alkali solution (NaOH) such as 5, 10, and 15%, and their physical, chemical, mechanical, morphological, and thermal properties were investigated experimentally. Due to alkali treatment, it was observed that the density of mulberry fibers increased while the diameter of fibers reduced. The chemical analyses showed that the cellulose content increased and hemicellulose, lignin, wax, and ash contents were found to be reduced due to alkali treatment. The chemical species present in the fibers were characterized by Fourier transform infrared spectrometry. In addition, tensile test showed that 5% alkali-treated fibers exhibited a tensile strength of 605.61 ± 41.34 MPa, tensile modulus of 11.78 ± 1.93 GPa, and strain at break of 4.73 ± 1.06%. The surface texture and thermal properties of raw- and alkali-treated fibers were examined using scanning electron microscopy and thermogravimetric analysis and differential thermogravimetric analysis.