Viscoelastic properties characterization of modified bamboo (Dendrocalamus asper) through acetylation assisted by supercritical CO2 S Silviana, M Petermann
Department of Chemical Engineering, Faculty of Engineering, Diponegoro University, Jl. Prof. Sudarto, SH Kampus Tembalang, 50275 Semarang, Indonesia
Particle Technology, Faculty of Mechanical Engineering, Ruhr University Bochum, Universitaetsstrasse 150, 44801 Bochum, Germany
Abstract
Acetylation of bamboo assisted by supercritical CO2 had been observed to overcome conventional modification regard with time and chemicals. The modification by acetylation had been executed to endure the bamboo in term of carbon capture storage in materials. This paper is aimed to identify the viscoelastic properties of acetylated bamboo such as glass transition temperature (Tg) using dynamic mechanical analysis (DMA) with a DMA Eplexor 500N instrument. Testing was performed in a heating range of 293 to 523 K at a rate of 2oC/min, with an oscillating torsional force applied at a frequency of 2 Hz. The untreated, dried bamboo exhibited a high Tg of 408 K. This Tg of the untreated bamboo reflected the same with Tg of the lignin and hemicellulose components, while the Tg is lower than that of the cellulose component, i.e. 516 K. The treated bamboo exhibited thermal softening releasing the Tg of lignin and hemicellulose decreased to 314 K and the Tg of cellulose shifted to 496 K owing to the plasticizing effect of the esterification reaction after the acetylation. Investigation of the thermoplastic behavior of solid acetylated bamboo indicated that the significant decrease in the Tg was resulted from acetylation reaction.
