BLENDS OF A THERMOTROPIC LIQUID-CRYSTALLINE POLYMER AND A THERMOPLASTIC ELASTOMER .1. MECHANICAL-PROPERTIES AND MORPHOLOGY

Blends of a thermotropic liquid crystalline polymer (LCP), Vectra A900 , and a thermoplastic elastomer, Kraton G1650, were made on a single s crew extruder. During extrusion, fibers of the LCP are formed under in fluence of shearing and elongating forces. The stiffness and tensile s trength of the elastomer are greatly improved by the addition of the L CP. The modulus of elasticity of blends containing up to 20% LCP can b e described well with the Halpin-Tsai equation. Differential scanning calorimetry and dynamic mechanical thermal analysis (DMTA) measurement s show that the polymers are immiscible, but the DMTA results show a s hift of the glass transition temperature of the elastomeric block of t he Kraton polymer. This shift may be attributed to a layer of elastome r adsorbed on the LCP particles.