The morphology and properties of ternary blends of polyamides, a thermotropic liquid crystalline polymer and a compatibilizer

Relationships between the properties of ternary blends of polyamides, a the rmotropic liquid crystalline polymer (TLCP) (poly(ester amide)) and a malei c anhydride grafted polyolefin are studied under various processing conditi ons. Thermal properties show the: compatibility in the ternary blend. The s hear viscosity of a ternary blend is slightly lower than that of a binary b lend. The morphology of the dispersed TLCP phase varies between droplets an d oriented fibrils when the drawing is weak, and is highly correlated with changes in tensile properties. Though there are some morphological differen ces depending on the matrix thermoplastics (nylon 6, nylon 66 or nylon 46), it is commonly observed that addition of the compatibilizer induces better adhesion at the interface as well as lower interfacial tension, and hence enables the deformation of the dispersed phase into elongated and fibril sh apes, even when the viscosity of the TLCP is much lower than that of the ma trices. Fibril development is favored in the strong elongational flow which was possible because the compatibilizer stabilizes the extrudate. In all c ases, it is manifest that, whenever applicable, extension is a decisive fac tor for TLCP fibril formation that is necessary for a significant improveme nt in tensile modulus and strength. There exists, however, an optimum compa tibilizer amount and optimum die exit temperature, both of which provide mo re uniform morphology and more fibril shapes which contribute to enhanced t ensile properties.