NMR investigation of the miscibility of new antiplasticizers in densely cross-linked epoxy–amine resins

The behaviour of antiplasticized epoxy–amine networks was investigated by variable-temperature determinations of 1H NMR free induction decays. Up to 50 °C, all antiplasticized resins exhibited a solid-like behaviour. At higher temperatures, resins containing the less polar additives were shown to be phase-separated, in contrast to systems containing polar additives. The temperature dependence of the phase composition of the resins, as detected by NMR, supports the conclusions previously deduced from the dynamic mechanical analysis (DMA) study: non- or slightly-polar antiplasticizer molecules are sharply phase-separated in highly cross-linked epoxy–amine networks cured extensively. The resulting morphology mainly consists in nano-scale aggregates of additives entrapped within the polymer matrix.