Compatibilization of poly(ether imide)/Rodrun blends by means of a polyarylate

A compatibilization method for improving the mechanical properties of thermoplastic/liquid-crystalline polymer (LCP) blends has been tested in blends of poly(ether imide), PEI, with a thermotropic copolyester (Rodrun). It is based on the addition to the blend of a third component, both miscible with the matrix and also able to interact with the LCP. Given the miscibility of a polyarylate (PAr) with PEI up to 20% PAr content, and its probable interactions with Rodrun, a constant 20% PAr was added to the PEI matrix to test its possible compatibilizer activity in PEI/Rodrun blends. The observed decrease in the interfacial tension between the matrix and the dispersed phase induced by the PAr gave rise to a smaller size and to fibrillation of the dispersed phase. Fibrillation also gave rise to improved modulus of elasticity and tensile strength, thus proving the compatibilization activity of PAr.