Dynamic mechanical analysis of viscoelastic properties of heat treated glycerol-impregnation poplar wood
The viscoelastic properties of glycerol-impregnated poplar wood after heat treatments at various temperatures were examined by dynamic-mechanical analysis. The spectra of storage modulus (E’) and loss tangent (tgδ) in the frequency at 10 Hz were measured at the temperature range from -100 to 300℃. Compared to no peak in E’ spectra and two relaxation processes in tanδ spectra of non-impregnated wood, two peaks in E’ spectra and two new relaxation processes in tanδ spectra were observed in the glycerol-impregnated wood. The magnitudes of the peaks decreased with the heat treatment temperatures. Both the peaks in E’ spectra and the new relaxation processes in tan δ spectra disappeared at the heat treatment temperature above 180℃. The analysis results suggested that there are special interactions between glycerol and wood polymer and the interactions completed at the higher temperature.