Positron annihilation lifetime spectra were measured for polyvinylalcohol doped with CuCl2 (0.5 to 5.0wt%) at temperatures rising from 30 degrees C to 160 degrees C (heating run) and then from 160 degrees C down to room temperature (cooling run). The data clearly revealed the glass transition (T-g) at around 90 degrees C. Both I-3 and tau 3 were decreased by the added CuCl2, being interpreted as the result of inhibition and quenching. Both the inhibition coefficient alpha and the quenching rate constant kappa were smaller than the corresponding values in liquids. The diffusion constant of ortho-positronium (o-Ps) estimated from kappa implies that o-Ps is not very mobile in the polymer. For all the samples tau(3) below T-g was always larger in the heating runs than in the cooling runs, but above T-g tau(3) was the same for heating and cooling runs. This is due to the existence of strain brought about by the process of preparation of the samples.