Effect of alkali treatment on physical and mechanical properties of bamboo short fibers

Bamboo (Arundinaria clarkei) short fibers were treated with 6% conc. NaoH solution for five different durations viz. 3 h, 6 h, 9 h, 12 h and 24 h. Effect on physical properties like diameter and density were studied. Fibers were examined using Scanning Electron Microscope (SEM) to study the effect of alkali treatment on its surface characteristics. Single fiber tensile tests were conducted to assess the tensile strength of the fibers. Comparative study of the SEM micrographs indicated removal of outer layer with the surface irregularities becoming more prominent with increasing duration. The fiber surface was scanned using an Atomic Force Microscope (AFM) to quantify the increase in surface roughness with alkali treatment. Tests results showed positive effect on the strength till 6 h beyond which the tensile strength was observed to reduce. Fourier Transform Infrared (FTIR) spectroscopy results indicated reduction in content of holocellulose along with hemicellulose, lignin and cellulose which explains the variation in tensile strength with increasing duration of treatment.