Dielectric relaxation behaviour of poly(cyclobutyl methacrylate)s

Dielectric behaviour of two poly(methacrylate)s with cyclobutyl groups in the side-chains has been studied. This investigation was performed by determining the dielectric permittivity and loss in terms of frequency and temperature for poly(cyclobutyl methacrylate) (PCBuM) and poly(cyclobutylmethyl methacrylate) (PCBuMM). Dynamic dielectric measurements show sub-glass relaxations, probably due to motions in the lateral chain, including the cyclobutyl ring. The effect of the insertion of a flexible spacer group into the side-chain is also analyzed. The α relaxations were analyzed in terms of the Havriliak-Negami equation and the free volume theory tested according to the Vogel-Fulcher-Tamman-Hesse equation. The conductive and interfacial phenomena were studied by hopping and MacDonald-Coelho models.