Effect of NaOH Concentration on Tensile Strength of Bamboo Hand Sheet

Abstract

In order to use bamboo as reinforcement in composite material, we first need to extract individual fibers from bamboo strips and re-fabricated as hand sheets. Those hand sheets contain millions of individual fibers contacting each other by their surface force and mainly hydrogen bonding. Therefore, different NaOH concentration used during the extraction stage would provide different surface properties impacting tensile strength of bamboo hand sheets. The objective of this study is to recommend suitable concentrations of NaOH for producing hand sheets as reinforcement material. Hand sheets were produced by cooked bamboo strips in different NaOH concentration, which are 1%, 6%, and 30% at 120oc for 2 hours. More than 10 samples of bamboo hand sheets with different treatments were submitted to mechanical tensile test following ISO 1924-1. It was found that the ultimate tensile strength and the Young’s modulus of bamboo hand sheets of the different specimen were globally similar. However, for low concentration, ultimate tensile strength and Young’s modulus increase while the NaOH concentration increases. On the other hand, higher values of NaOH concentration do not only extract bamboo fiber but also severely alter bamboo fiber shape. The best ultimate tensile strength and Young’s modulus values are presented by 6% NaOH which are 0.95 kN/m2 and 236.4 MPa respectively.