A study has been made on the thermal and rheological properties of the blends of Polycarbonate (PC) and p-Quarterphenyl derivatives (QP). QP, known as a thermotropic liquid crystalline material, does not decompose thermally at the normal molding temperatures for engineering polymers. The aim of this study is to clarify how the phase structures of these blends affect their rheological properties. The results obtained are as follows:
(1) PC/QP system is well represented by an UCST phase diagram. The phase containing an excess amount of QP consists of crystals.
(2) In the incompatible region, the existing crystals cause long relaxation behavior. When the crystals melt at high temperature, the viscosity of the system decreases considerably.
(3) The degree of decrease in viscosity of the system is dependent on the chain length of the substituent of QP.