Hydrogen bond chains and dielectric relaxation of polyvinyl alcohol

The dielectric constant ϵ′ and the loss factor ϵ″ of untreated and heat‐treated polyvinyl alcohol and of a deuterated polyvinyl alcohol were observed over the frequency range of 30–106 cycles/sec. at several temperatures. For comparison, ϵ′ and ϵ″ of two normal long‐chain alcohols were also measured. Polyvinyl alcohol has its ϵ″ peak at a frequency of 104−105 cycles/sec., and activation energies E* for dielectric dispersion are quite small (6–18 kcal./mole), despite the large relaxation time. This finding cannot be explained by the theory of restricted rotation of dipoles, but can be explained by the use of the concept introduced by Sack of the chain mechanism of dielectric relaxation in hydrogen‐bond chains. It is concluded that hydrogen‐bond chains in the amorphous regions of polyvinyl alcohol have a mean length of about 1350 A. and are shortened only very slightly by deuteration.