ABSTRACT
The blending route is particularly important for polymer liquid crystals (PLCs). Mechanical and thermophysical properties of PLCs are much better than those of engineering polymers. To analyze the inherent nature of PLCs, consider the process of drawing a specimen in the flow direction. Given the proclivity for orientation prevailing in PLCs, the degrees of alignment achieved here are higher than can be produced by the cold working of metals. A blend containing 50% of each of the components can have properties close to the pure engineering polymers (EP), or close to the pure PLC, or in between, or far outside of the additivity curve. EPs are typically flexible, with relatively low mechanical strength, low upper service temperature, and large thermal expansivity. A well-established procedure for improving the properties of EPs consists of inserting rigid reinforcement; the resulting materials have been called heterogeneous composites.
