Change of distribution of free volume in a polymer caused by crystallization

The marked effect of crystallization on the shape of loss-permittivity-vers us-frequency curve of poly(aryl ether ketone ketone) reported by [Ezquerra ct nl.: Phys. Rev. B 50 (1994) 6023] is explained by a simple theory assumi ng a distribution of free volume which has been successfully used to explai n the temperature dependence of the shape of loss-permittivity-versus-frequ ency curve in various polymers. From this result the relation between the d istribution of free volume and the degree of crystallinity is clarified.