Thermal stability of side-chain polymer liquid crystals

Five simple-comb polymer liquid crystals-four polyacrylates and one polysiloxane-were studied using thermogravimetric analysis. A simple kinetic model was used to access the activation energy of the weight loss events. For the polyacrylates one main degradation process was observed with activation energy around 165 kJ/mol, probably involving intramolecular transfer, which would include a coupled weight loss mechanism of both polymeric backbone and mesogenic side-groups. For the studied polysiloxane, two overlapped mechanisms are observed that suggest separate mechanisms for the degradation of side-groups and main chain.