Mechanism Analysis of Thermal Treatment for the Mechanical Properties of Bamboo Fiber-Based Composites

Abstract

High-performance bamboo fiber-based composites (BFBC) is a typical application to achieve high efficiency of bamboo for sustainable engineering. As the important pretreatment during the manufacture process of BFBC to improve its dimensional stability and weather resistance, thermal treatment would weaken mechanical properties, whose influence mechanism has not been determined. Herein, we mainly focus on the main bearing substance of BFBC- bamboo cellulosic fibers (BCFs), to clarify the relationship between the macroscopic mechanical properties of BFBC and microstructure of BCFs by studying their microscopic mechanical properties, crystal structure, and degree of polymerization (DP) under thermal treatment at 140 °C and 200 °C. With the temperature increased, the diameter and orientation of BCFs basically remain unchanged, the crystallinity increases slightly, but the DP of cellulose is decreased, which lead to the decrease of tensile strength of BCFs. The macroscopic mechanical properties of BFBC are positively correlated with the micromechanical properties of BCFs.

Keywords: Thermal treatment, Bamboo fiber-based composites, Mechanical properties, Bamboo cellulosic fiber