Acoustic phonons in an epoxy resin studied by Brillouin light scattering

Author

Comez, L.D. ; Fioretto, D. ; Palmieri, L. ; Socito, G. ; Verdini, L.

Author_Institution

Dipt. di Fisica, Perugia Univ., Italy

Volume

1

fYear

1997

fDate

5-8 Oct 1997

Firstpage

731

Abstract

The elastic and viscoelastic properties of the epoxy system Epon 828 have been studied by means of the Brillouin light scattering (BLS) technique. The specimen, consisting of a transparent epoxy film supported by an opaque substrate, has been analyzed by means of a high contrast Fabry-Perot tandem interferometer. The characteristic frequency and lifetime of longitudinal and transverse acoustic modes have been measured in a wide temperature range, above and below the glass transition temperature T_g=257 K. From these data, the temperature behavior of both the teal and imaginary pair of the elastic moduli was obtained at the frequency of the Brillouin peak (≈10 GHz). Evidence is given of a very broad dispersion associated to both a structural and secondary relaxation. A full spectrum analysis has been also performed in order to determine the frequency dependence of the longitudinal elastic modulus

Keywords

Brillouin spectra; elastic moduli; glass transition; phonon spectra; polymers; viscoelasticity; Brillouin light scattering; Epon 828; Fabry-Perot tandem interferometry; acoustic phonons; dispersion; elastic modulus; epoxy resin; glass transition temperature; opaque substrate; secondary relaxation; spectrum analysis; structural relaxation; transparent film; viscoelastic properties; Brillouin scattering; Elasticity; Epoxy resins; Fabry-Perot; Frequency; Light scattering; Phonons; Substrates; Temperature distribution; Viscosity;

fLanguage

English

Publisher

ieee

Conference_Titel

Ultrasonics Symposium, 1997. Proceedings., 1997 IEEE

Conference_Location

Toronto, Ont.

ISSN

1051-0117

Print_ISBN

0-7803-4153-8

Type

conf

DOI

10.1109/ULTSYM.1997.663120

Filename

663120