ISSN:
1573-482X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Electrical Engineering, Measurement and Control Technology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The dielectric properties of latex water-cast and conventional solvent-cast epoxy neat resin systems were investigated under three formation conditions: solvent-based as-made, water-based as-made, and water-based following a boiling fluid extraction procedure to remove residual surfactant. Samples from each of these three groups were cast, cured, and exposed to controlled humidities in an environmental chamber at room temperature and elevated temperature, a steam bath at various temperatures, and soaked in boiling water. Composite laminates, press fabricated using solvent and latex-based epoxy impregnated glass cloth, were subjected to similar environmental exposure. The microwave frequency dielectric properties of these materials, after each environmental exposure, were measured at 9.4 GHz. These dielectric measurements revealed that under identical exposure conditions, water-borne epoxy systems absorbed more water than solvent-based systems and also allowed more free water into the samples. Extraction of water and soluble components in the resin had no effect on the dielectric properties of the water-borne samples. The presence of high quantities of free water at moisture fractions beyond 4.0 wt %, suggests that the differences between the dielectric properties of solvent and water-borne epoxy systems are due to void morphology, which was confirmed by optical and electron microscopy. ©1999Kluwer Academic Publishers
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1008939426270
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