Polysiloxane dizwitterionomers. IV. Mechanical and dielectric relaxations

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Abstract
The relaxation behavior of a series of polysiloxane dizwitterionomers has been studied by using dynamic mechanical and dielectric spectroscopy. The temperature range was 100–375 K and the frequency was ca. 1 Hz in the mechanical measurements and 50 Hz–50 kHz in the dielectric measurements. Three relaxation regions, labeled αs, β, αz in order of increasing temperature, were observed. The βs relaxation was assigned to the nonionic portion of the siloxane chain and correlated with the glass transition of polydimethylsiloxane. The β and αz processes are ionic‐related relaxations; β probably originated from the motion of a chain segment carrying a dizwitterion, and αz, from the collapse of the organization in the ionic domains. Absorbed water exerts a profound influence on relaxation behavior–primarily on αz ionic relaxation and the relative rigidity of the samples. The water molecules solvate the ions and thus shift the αz relaxation to lower temperatures.Some aspects of the effect of thermal history on the microphase separation into domains have also been investigated. The results indicate that the organization of the zwitterions in the ionic domains is improved at slow cooling rates.