Le Comportement Diélectrique des Polymères en Solutions Diluées III. Influence du Solvant sur le Moment Dipolaire et sur la Relaxation Diélectrique

Abstract

Dielectric properties of dilute solutions of polymethyl methacrylate in toluene, chloroform and 1,2‐dichloro ethane, and of polybutyl methacrylate in carbon tetrachloride, in dioxan, in toluene, chloroform and 1,2‐tetrachlor ethane have been measured in a wide frequency range (0,5 Kcycle/sec. to 30 Mcycle/sec.) at temperatures varying from − 30°C to + 25°C. Previous conclusions concerning the influence of temperature and molecular weight have been confirmed.It has been shown that dipole moments in vacuo, extrapolated to infinite dilution, are independent of the solvent.The influence of the solvent on the critical frequency and average relaxation time cannot be explained simply by a viscosity effect. Thus our results are in favour of the theory elaborated by de Brouckère and Mandel. Activation energies are higher for the butyl‐esters than for the methyl esters, and are lower for the more polar solvents.