Miscibility and Dynamic Mechanical Behavior of Blends with LCP'S

Abstract
The main advantage of the "in situ" production of blends of thermoplastics with liquid crystalline polymers (LCP's) is viscosity reduction. In this work the phase behavior of blends of poly p-phenylene sulphide (PPS) with two different LCP's is presented. The LCP's are HX1000 (amorphous) and HX4000, crystalline, both from DuPont. The samples were prepared by injection molding and its dynamic mechanical properties were tested after annealing. It was observed that before annealing the blends were slightly miscible at all concentrations. It was also observed a plasticization of the PPS amorphous fraction by the LCP amorphous part. After annealing an increase of the PPS glass transition temperature was observed ; the blends were also find to be immiscible. An average β-transition was observed at aproximately 76°C (HX1000) and at 88°C (HX4000) ; the glass transition temperatures were 160.48°C (HX4000) and 171.77°C (HX1000).