Dielectric relaxation properties of linear polythioethers

Values of the dielectric loss tangent were obtained as a function of temperature for poly(pentamethylene sulfide) (P5MS) and poly(1,3-dithiocane) (PDTC). Both P5MS and PDTC exhibit a β absorption, located in the vicinity of their respective glass transition temperatures, ?105°C and ?73°C, which is believed to be associated with micro-Brownian motions in the amorphous phase of the crystalline polymers. The glass-rubber transitions of the polymers are discussed in terms of the flexibility of the chains, as expressed by their conformational partition functions and entropies.