Thermal behaviour of unsaturated polyester resins + poly(3-octylthiophene) blends

Blends of poly(3-octylthiophene) (POT) with unsaturated polyester (UP) resin have been investigated. Two glass transition temperatures, Tg, were detected by differential scanning calorimetry (DSC) in blends of POT+uncured polyester resins, which indicate the partial immiscibility of these systems. It has been demonstrated that the miscibility behaviour of these blends depends up to a point on the solvent used in sample preparation. Also POT was found to be immiscible with crosslinked polyester resins which was concluded from the results of thermal analysis. The influence of the presence of POT on the crosslinking reaction, the miscibility of the crosslinked system and finally the melting behaviour of POT were analysed. The results obtained have been compared in the crosslinked and uncrosslinked blends.