Dynamical Study on the Secondary Anomalous Absorption Region of Polymethyl Methacrylate

Abstract

Secondary absorption region of polymethyl methacrylate was studied dynamically. In addition to the absorption region, which corresponds to so-called second order transition or softening temperature, a secondary absorption region was found at lower temperature, its peak being lower and broader. By means of bending and torsional vibrations, frequencies for the maximum absorption were measured at several temperatures. The activation energy of 29 kcal/mol was obtained. The results of the experiment were compared with those obtained electrically by Mead and Fuoss.