Year-end Sale % OFF 
Abstract
Dielectric measurements (5Hz–8.5 GHz) at temperatures from –30 to 100°C have been made on polar solutes molecularly dispersed in a polystyrene matrix. Rigid molecules of varying size and shape (camphor, anthrone, cholest-4-en-3-one, tetraphenyl cyclopentadienone) and β-naphthol are considered. By 80° all the molecules show their full dipole moments in polystyrene : the apparent (Eyring) activation energies ΔH*E for molecular dipole relaxations vary from 0.9 kcal mole–1 for camphor to 130 kcal mole–1 for tetracyclone. The apparent ΔH*E over limited temperature ranges themselves reflect changes in the polymer matrix relaxations, and the 130 kcal mole–1 value may well be derived from the glass-transition process. The ΔH*E and ΔS*E correlate linearly and the former is dependent upon the molecular rotational volume. The “whole molecule” and hydroxyl group rotations are well resolved for β-naphthol with ΔH*E values of 11.2 and 0.5 kcal mole–1 respectively.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
