Ammonium salts of pre-gelled epoxy networks, in the form of spherical
clusters, were prepared by the addition of hydrogen chloride in methan
ol solution to partially cured bisphenol A diglycidyl ether/ethylene d
iamine epoxy resins. The formation of ammonium salts resulted from the
interaction of hydrogen chloride with the amine groups of the pre-gel
led epoxy networks, as indicated by their infra-red and solid-state C-
13 n.m.r. spectra and X-ray diffraction patterns. By increasing the ti
me allowed for branching reactions or by increasing the concentration
of branched molecular chains, the spherical clusters tended to form as
agglomerations of ribbon textures, which were then demonstrated to be
associated with the packing of the branched molecular chains. The pac
ked networks could also be detected through X-ray diffraction studies
of the post-gelled epoxy resins.