Dipole relaxation in polyethyl methacrylate and polyethyl acrylate as a function of frequency, temperature and pressure. The α, β and αβ relaxations

Abstract

The dielectric relaxation in polyethyl methacrylate has been studied over a wide range of frequency, temperature and pressure (up to 3000 atm). Three relaxation regions α, β and (αβ) were observed. The α relaxation moved rapidly to lower frequencies with increased pressure, whereas the β relaxation was quite insensitive in location to this variable. The (αβ) relaxation was split into α and β processes with increased pressure. The α relaxation in polyethyl acrylate moved rapidly and continuously to lower frequencies as pressure was increased.

The α, β and (αβ) relaxations are discussed in terms of molecular mechanisms. A comparison of dipole relaxations in the alkyl methacrylate series must be made with caution in view of the α and (αβ) relaxations which occur in these polymers.