1204
Macromolecules 2001, 34, 1204-1213
Gradient Interphase between Reactive Epoxy and Glassy Thermoplastic from Dissolution Process, Reaction Kinetics, and Phase Separation Thermodynamics Bernard Lestriez,† Jean-Paul Chapel,‡ and Jean-Franc¸ ois Ge´ rard*,† Laboratoire des Mate´ riaux Macromole´ culaires-UMR CNRS 5627, Institut National des Sciences Applique´ es, 20, Avenue A. Einstein, 69621 Villeurbanne Cedex, France, and Laboratoire des Mate´ riaux Polyme` res et Biomate´ riaux-UMR CNRS 5627, Universite´ Claude Bernard Lyon I, Baˆ t 303, 69622 Villeurbanne Cedex, France Received July 13, 2000; Revised Manuscript Received November 28, 2000
ABSTRACT: Planar interfaces have been prepared by assembling high-Tg thermoplastics such as poly(phenylene ether) (PPE) or poly(ether imide) (PEI) and epoxy-amine networks at different conversions of the epoxy groups, Xe, followed by a complete curing. Direct evidence of the structure of the interfacial regions was made by means of electron microscopies, SEM and TEM, and atomic force microscopy, after a complete curing of the epoxy-amine. The morphologies of the interfaces are explained from the competition between the dissolution process of a thermoplastic by nonreactive solvent and the thermodynamics and the kinetics of reactive epoxy-amine/thermoplastic system. If the phase diagram indicates that the epoxy-amine/thermoplastic system is nonmiscible, the interface remains very thin (
