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Dielectric relaxation spectroscopy of reactive network-forming polymers

โœ Scribed by Benjamin D. Fitz; Jovan Mijovic

Publisher
John Wiley and Sons
Year
1998
Tongue
English
Weight
341 KB
Volume
9
Category
Article
ISSN
1042-7147

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โœฆ Synopsis

Dipole dynamics in network-forming epoxy-amine formulations were investigated by dielectric relaxation spectroscopy. The unreacted liquid monomer mixture was characterized by a single ab process at high frequencies. The ab relaxation peak broadens with the progress of chemical reactions and separates into two peaks: a which shifts to lower frequencies and longer relaxation times, and a second peak at high frequency (megahertz range) of diminishing intensity, but essentially unchanging relaxation time. The most probable relaxation times were calculated and plotted as a function of reciprocal temperature resulting in activation energy plots. It was shown that the splitting of the ab process into a and b processes can be brought about by either cooling a liquid without changing its structure, or continuing chemical reactions (i.e. changing the structure) while maintaining a constant temperature.

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