From the complete description of neat systems and the determination of
phase diagrams, the influence of a nonfunctionalized initially solubl
e thermoplastic on epoxy-amine kinetics was discussed, considering the
dilution effect induced by the additive. The initially soluble thermo
plastic, a poly(ether imide), PEI, can act as a catalyst when the init
ial reactivity of the epoxy-amine system is very low. The conversion,
x(cp), at which phase separation occurs depends on the initial miscibi
lity of PEI in the mixture of monomers. Both structural transformation
s, gelation and vitrification, were found to be affected by the phase
separation process because of the induced fractionation phenomena. The
evolution of phase diagrams which cure was also considered and temper
ature-conversion-transformation (TxT) diagrams were presented.