Dielectric Spectroscopy of Poly(Ethyl Methacrylate)-Carbon Dioxide System

摘要

The investigation on the interactions of polymers with sub and supercritical fluids (SCFs) by dielectric spectroscopy was the aim of this work. The dissolution of the dense gas in the polymeric matrix causes different phenomena, such as the reduction of glass transition temperature and melting point. These effects are due to the increase of the chain and segmental mobility of the polymer and are referred to as "dense gas plasticization". To study them, dielectric spectroscopy measurements of poly(ethyl methacrylate) (PEMA) were carried out in carbon dioxide (CO_2) at high pressure. Real and imaginary components of dielectric spectra are analyzed in order to study the relaxation phenomena of this macromolecular system.