Relaxational study of poly(2-chlorocyclohexyl methacrylate) by thermally stimulated current, dielectric, and dynamic mechanical spectroscopy

A comparative study of the mechanical and dielectric relaxation spectra of poly(2-chlorocyclohexyl methacrylate) (P2CCM) is reported. Two clear relaxational zones are found. The spectra present a moderate subglass γ absorption, followed in increasing temperature order by a prominent α glass-rubber relaxation process. The last peak is not clearly observed in dielectric measurements due to conductivity effects which overlap the loss permittivity spectrum. Moreover, evidence of remnant mechanical as well as dielectric activity is observed near room temperature. This phenomenon has already been observed in poly(2-chlorocyclohexyl acrylate) (P2CCA). To describe in a suitable way these results, a deconvolution method has been proposed to get information about the relaxational behavior of this polymer. A more detailed analysis about the third relaxation called β, between α and γ relaxations, has been achieved by using the thermally stimulated depolarization current technique (TSDC). Special attention was devoted to the analysis of the molecular motion that produces dielectric and mechanical activity in glassy P2CCM as well as to link the elementary TSDC to the ac dielectric spectra. A comparative study of P2CCM and P2CCA is also reported.