Dielectric losses and polarization of polymers

Abstract

Results of research on the dielectric losses and polarization of polymers are presented. In the first and second parts of the paper these behaviors of the polymers are considered for high‐elastic state. The dielectric losses are shown to be of relaxation character since they can be described by the segmental thermal motion of polymolecules. The second part deals with effective dipole moments of elementary chain units of macromolecules of the homologous series of methacrylic acid esters. It is stated that for the polymers under consideration the intramolecular interaction is of considerable significance. The third part of the report supplies data on the dielectric losses and polarization research of the same polymers in the glassy state. In this case the losses of relaxation character, called dipole‐radical, are observed, as they can be described by the thermal motion of separate polar groups or radicals. The application of the method of effective dipole moments for analysis of the experimental date has brought us to the conclusion that it is the intermolecular interaction which is of greater importance for the dipole‐radical losses.

Sequential homo‐interpenetrating polymer networks of poly(2‐hydroxyethyl methacrylate): Synthesis, characterization, and calcium uptake

“…These events, which are related to energy absorption, are known as “transitions,” “relaxations,” or “dispersions.” The transition regions detectable in glass‐forming amorphous polymers through a number of methods—especially dielectric spectroscopy, DMA or DSC—are traditionally labeled as α, β, γ, δ, etc. from the higher to the lower temperature (i.e., T α > T β > T γ > T δ > ...) 47, 65–76. It should be mentioned that transitions occurring at temperatures lower than T γ have been seldom reported.…”

Dielectric and Mechanical Relaxational Behavior of Poly (Chlorobenzyl Methacrylate)s

“…In the case of poly(4-chlorophenyl methacrylate) [15] and poly(dichlorophenyl methacrylate) [16] Kirkwood correlation function Table 6. This indicates that the intermolecular contributions do not significantly affect the correlation factor at these temperatures as suggested by Williams [17][18].…”

Mechanical and scratch behaviors of polyrotaxane‐modified poly(methyl methacrylate)

“…In fact, the effect of the length of the alkyl side group of PMMA on the apparent activation energy of the β-process has been unclear. 38,39 According to Ishida and Yamafuji, 31 PMMA is considered to have a "flexible" dipole whose micro-Brownian motions are active even below T g . PMMA has two kinds of dipoles coming from the methyl and the ester groups.…”