Thermosetting PDLCs: Cure, morphology and thermo-optical response

Two thermosetting matrices based, respectively, on an unsaturated polyester resin and a bifunctional epoxy resin were employed to prepare Polymer Dispersed Liquid Crystal (PDLC) systems. A molecular, morphological and thermo-optical characterisation of these systems is presented. The unsaturated polyester based system was found to be phase-separated at all compositions. Image analysis demonstrated morphological features suitable to achieve interesting thermo-optical properties, particularly for the composition containing 40 wt % of LC. The epoxy based system was found to be miscible before curing at all compositions. A phase separation occurred upon curing for LC contents higher than 40 wt %. In this composition range also this system behaves as an efficient thermo-optical switch.