title: Nanoindentation study of interphases in epoxy/amine thermosetting systems modified with thermoplastics.
abstract: The characterization of a mixture of epoxy/amine with different stoichiometric ratios was carried out by means of nanoindentation. The epoxy system was composed by diglycidyl ether of bisphenol-A and 4,4'-methylene bis-(3-chloro 2,6-diethylaniline). Diffusion through interface formed by epoxy/amine system in stoichiometric ratio and several thermoplastic polymers was also analyzed by means of stiffness analysis, as studied by atomic force microscopy (AFM) and coupled nanoindentation tests. Used thermoplastics were an amorphous, atactic polystyrene, and two semicrystalline, syndiotactic polystyrene and poly(phenylene sulfide). Larger range diffusion was obtained in epoxy/amine systems modified with atactic polystyrene while the study of the influence of stoichiometric ratio suggests that the excess of epoxy generated stiffer material. In addition, larger indentation loads resulted in higher apparent stiffness because of the more number of polymer chains that had to re-accommodate owing to the increase in contact area.
authors.affiliation: Materials+Technology Group, Departamento de Ingeniería Química y M. Ambiente, Escuela Univ. Politécnica, Universidad País Vasco/Euskal Herriko Unibertsitatea, Pz. Europa 1, 20018 Donostia/San Sebastián, Spain.
authors.forename: Jose Angel
authors.initials: JA
authors.lastname: Ramos
authors.forename: Miren
authors.initials: M
authors.lastname: Blanco
authors.forename: Iñaki
authors.initials: I
authors.lastname: Zalakain
authors.forename: Iñaki
authors.initials: I
authors.lastname: Mondragon