DYNAMIC MECHANICAL THERMAL ANALYSIS OF MOSO BAMBOO (Phyllostachys heterocycla) AT DIFFERENT MOISTURE CONTENT

Abstract

Bamboo is a type of biomass materials that has great potential as a bio-energy resource in China. The thermal-mechanical behavior of bamboo plays an important role in the formation process of pellets. To investigate the effect of moisture content (MC) on thermal-mechanical behavior of bamboo, the storage modulus and loss factor of moso bamboo was determined using dynamic mechanical thermal analysis (DMTA) from -50 to 150 oC. The experimental results showed that the general feature of bamboo thermal-mechanical properties with temperature is similar to other cellulosic materials, and they are affected by MC. A substantial decrease of storage modulus over the entire temperature range implies that bamboo underwent a glass to rubber transition. Bamboo, at lower MC, has a higher storage modulus, which decreases the mechanical strength of pellets. The loss factor exhibited two major transitions for all samples. There was an α-transition (α1), attributed to glass transition of lignin, peaking in a higher temperature range. The second major relaxation (α2), located in a lower temperature range, was attributed to glass transition of hemicelluloses. Activating lignin and hemicelluloses using moisture and temperature in the temperature range of glass transition can be very helpful to achieve durable particle-particle bonding.