The effects of thermal modification on the properties of two vietnamese bamboo species, Part I: Effects on physical properties

Abstract

Bamboo is a very interesting bioresource for use as a building material because of its properties of strength in combination with low density. However, its susceptibility to fungi and insects is problematic for its usage. Thermal modification is used in Vietnam to improve the durability and dimensional stability of bamboo. The thermal modification causes many changes related to the physical properties of bamboo, e.g., mass, color, and equilibrium moisture content (EMC). All these changes are dependent on the modification conditions (modification temperature and duration). The mass loss (ML), the color difference (δE*ab), and the reduction of EMC (δEMC) were due to the thermal modification increase with higher temperature and/or longer duration. Therefore the temperature had greater influence than the modification duration. The changes were slight at 130 °C (ML: 0,3...0,6%; δE*ab: 3...5; δEMC: 0,5...0,8 % ), moderate at 180 °C (ML: 1,5...4 %; δE*ab: 21...37; δEMC: 3,6...4,4 %), but very strong at 220 °C (ML: 14...16 %; δE*ab: 46...51; δEMC: 5,6...5,7%). There are close correlations between the changes mentioned above.