EXPERIMENTAL DISTRIBUTION FUNCTIONS OF ACTIVATION ENERGIES AND RELAXATION TIMES OF SEGMENTAL MOTION IN AMORPHOUS POLYMERS.

The method of fractional thermostimulated depolymerization was used to obtain the distribution functions of activation energies, frequency factors and relaxation times for segmental rotational motion in PMMA, PVAC and PVC. The distributions are described well by exponential equations. The width of the energy spectrum (at a fraction 1/e of the height) is practically identical for the three studied polymers and amounts to 171 plus or minus 5 kJ/mole. The width of the relaxation time spectrum is temperature-dependent, and is described for the studied systems at T less than T//g by a single equation: GAMMA equals 1 plus 9 multiplied by 10**3(1/T-1/T//g).