INVESTIGADORES
GALANTE Maria Jose
artículos
Título:
Influence of the Addition of Polystyrene-b-Poly(methyl methacrylate) Block Copolymer (PS-b-PMMA) on the Morphologies Generated by Reaction-Induced Phase Separation in PS/PMMA/Epoxy Blends
Autor/es:
EMMANUEL GIRARDT-REYDET; ANNE SEVIGNON; JEAN PIERRE PASCAULT; C. E. HOPPE; M.J .GALANTE; P.A. OYANGUREN; R.J.J. WILLIAMS
Revista:
MACROMOLECULAR CHEMISTRY AND PHYSICS
Editorial:
WILEY-V C H VERLAG GMBH
Referencias:
Lugar: Weinheim; Año: 2002 vol. 203 p. 947 - 952
ISSN:
1022-1352
Resumen:
Homogeneous solutions of polystyrene (PS)
and poly(methyl methacrylate) (PMMA) in diglycidylether
of bisphenol A, containing about 8 wt.-% total thermoplastic,
and with or without 0.5 wt.-% of a PS-b-
PMMA block copolymer, were polymerized in two ways
(i) in the presence of a tertiary amine (benzyldimethylamine,
BDMA), or (ii) using a stoichiometric amount of a
diamine (4,49-diaminodiphenyl sulfone, DDS). A double
phase-separation was recorded by light transmission during
polymerization. A PS-rich phase was separated at low
conversions and a PMMA-rich phase was segregated at
more advanced conversions. The addition of the block
copolymer produced significant changes in the morphologies
generated. For the BDMA-initiated polymerization,
the presence of the block copolymer made the small
PMMA-rich domains clearly discernible in transmission
electron microscopy (TEM) micrographs. For the DDScured
system, the addition of the block copolymer led to a
dispersion of small PS-rich particles encapsulated by
PMMA shells. The possibility of generating a stable dispersion
of biphasic particles by polymerization-induced
phase separation opens a new way to modify thermosetting
polymers for toughening purposes.