Effects of thermal treatment on surface color, dimensional stability and mechanical properties of bamboo-based fiber composites

Bamboo fibrous veneers were fabricated using a new technology and heat-treated in a vacuum by steaming at pressure of 0.40 MPa (151°C) for 170 min. Bamboo-based fiber composites (BFC) were made from bamboo fibrous veneers that were before and after thermal-treated using a compression molding method. The results pointed out that, chemical degradation occurred in bamboo fibrous veneers, mainly in relation to hemicelluloses, and its reduction reached 59.15%. The pH value decreased significantly, whereas acid buffering capacity increased compared with control samples. The color of thermal-treated BFC was darkened; dimensional stability was significantly improved by reducing thickness swelling and wideness swelling. The mechanical properties were affected with reduction in Modulus of Rupture (MOR) and Horizontal Shear strength (HS), but Modulus of Elasticity (MOE) was affected slightly. Thus it is shown that the surface color and dimensional stability of BFC can be changed and improved by thermal treatment.