✦ LIBER ✦

Dielectric properties of a curing epoxy/amine system at microwave frequencies

✍ Scribed by Mark C. Finzel; Martin C. Hawley; Jinder Jow

Publisher: Society for Plastic Engineers
Year: 1991
Tongue: English
Weight: 391 KB
Volume: 31
Category: Article
ISSN: 0032-3888
DOI: 10.1002/pen.760311614

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

Dielectric data collected at 2.45 × 10^9^ Hz has been analyzed using a mean relaxation time model over the temperature range 50 to 100°C and at extents of cure from 0 to 57% for a stoichiometric DER 332 (Dow)/DDS (Aldrich) mixture. The relaxation times thus obtained obey the Arrhenius law and tend to increase with the extent of cure. This corresponds to the more rigid nature of the molecular structure as the network forms and the dipolar relaxations become more inhibited. Decreases in the activation energy of the relaxation along with a widening of the relaxation time distribution imply that the relaxations involve ever shorter chain segments as the extent of cure increases.

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