抄録
A theoretical equation is derived to determine the tan δ-temperature(T)curve of the system composed of a single relaxation time, and the curve is calculated. Comparison of the calculation with experimental results shows that; (1) The three-element model combining the Maxwell element with one spring parallelly is most suitable for a viscoelastic model having a peak in the tan δ-T curve. (2) The peak temperature in the tan δ-T curve, Tmax (k), and the apparent activation energy ΔHa, give the inherent half value width of tan δ-T curve ΔT1/2(s) by the equation ΔT1/2(s)=5.240×10-3 Tmax2/ΔHa. (3) The log tan δ-T curve can be approximated by an equilateral triangle. (4) The parameter B∞ defined by the equation B∞=522ΔHa/Tmax, is convenient for determining the mechanism of viscoelastic absorption. (5) The average ΔT1/2(s) of various polymers is 13 deg for the absorption (αa) related to the microbrownian movement of segment in amorphous, and 20 deg for the absorption (βa) related to the local movement of the main chain. Thus, the value of βa absorption is larger than that of αa absorption. (6) A method is presented to determine the relaxation time at the glass transition temperature Tg by ΔHa and Tmax.
