Not only does the degree of crystallinity but also the extent of thermal degradation affects the molecular mobility above Ts. Figure 2d shows the fractional change in resistance of the sample annealed at 200°C for 5 h. No peak due to molecular movement above Ts was observed. The degree of crystallinity was less than that of the as-received sample, as shown by ∆H in Table I. However the higher extent of thermal degradation resulted in less molecular movement above Ts.