Characterization of Epoxy Foams

P. M. STEFANI; A. TEJEIRA BARCHI; J. SABUGAL; A. VAZQUEZ

JOURNAL OF APPLIED POLYMER SCIENCE

wiley

Año: 2003 vol. 90 p. 2992 - 2996

0021-8995

Epoxy foams were prepared from the commercial system (LY 5054 epoxy resin, HY 5054 amine as curing agent, and DY 5054 siloxane as foaming agent) supplied by Ciba-Geigy. From the differential scanning calorimeter results the optimal epoxy–amine ratio was determined. A maximum Tg
value of 85°C was found for an epoxy–amine ratio of 100:35 by weight. In this system, the siloxane reacts with the amine releasing hydrogen that acts as the real foaming agent. The density decreased from 490 to 215 kg/m3 as the epoxy:blowing agent ratio increased from 100:1 to 100:3 by weight of the reactive mixture. Under the synthesizing conditions, the glass transition temperature(Tg
) of the foam did not vary significantly as the blowing agent increased. The modulus and compressive strength of the foam exhibited a power-law dependence with respect to density of the form: E(
)n, where n1.8. Scanning electron microscopy analysis verified that the foam have a closed cell structure. The relation between composition, final morphology, density, and properties of the foam was analyzed.© 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2992–2996, 2003Key words: foam; mechanical properties; epoxy; blowingagent