PROPERTIES OF A SEMICRYSTALLINE AND AN AMORPHOUS THERMOTROPIC LIQUID-CRYSTALLINE POLYMER

The physical properties, thermal stability, rheology and tensile properties of a commercial semi-crystalline and an amorphous thermotropic liquid crystalline polymer (TLCP) have been investigated. Analysis by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) confirm the presence of a small melting endotherm and a glass transition in the former material. The as-received amorphous TLCP exhibits no obvious melting endotherm and a strong glass transition is detected. The flow and tensile properties of the semi-crystalline polymer are dominated by the presence of the crystalline to nematic transition temperature. The properties of the amorphous TLCP appear to be governed by increasing mobility afforded by increasing temperature. Based on flow behaviour and further DSC analysis it has been shown that under appropriate annealing conditions the as-received amorphous TLCP can develop solid crystalline order.