Compatibilization of Blends Containing Thermotropic Liquid Crystalline Polymers With Sulfonate Ionomers
Zinc salts of lightly sulfonated polystyrene ionomers (Zn-SPSs) are shown to be effective compatibilizers for blends of a wholly aromatic liquid crystalline polyester (LCP) with nylon 66 (PA66) and polycarbonate (PC). Zn-SPS is miscible with PC, PA66 and the LCP, though the origins of miscibility are different for the three binary blends. Zn-SPS and PA66 mix because of strong intermolecular attractive interactions between the sulfonate and amide groups, while the ionomer is miscible with PC and the LCP as a result of intramolecular repulsive interactions along the ionomer molecules. The addition of Zn-SPS to LCP/PA66 and LCP/PC blends reduces the dispersed phase size and improves the adhesion between the phases. The compatibilized blends have significantly higher tensile modulus and tensile stress at break than the blends without ionomer.