Effect of poly (esterimide)s as compatibilizers on the physical properties of poly(etherimide)/thermotropic liquid crystalline polymer in-situ composites

This study investigates the compatibilizing effect of poly(esterimide) (PEsI) on the blend of poly(etherimide) (Ultem 1000; Ultem from General Electric Company) and thermotropic liquid crystalline polyesteramide (Vectra B950; Vectra B from Hoechst Celanese). Two types of polyesterimide (PEsI) were prepared as compatibilizers to improve the interfacial adhesion of incompatible Ultem and Vectra B. Poly(ethyleneterephthalate) (PET) based PEsI (EI10) and poly(butyleneterephthalate) (PBT) based PEsI (BI10) including 10mol% of the imide are prepared. The binary Vectra B/PEsI and Ultem/PEsI blends were investigated in terms of thermal properties. This revealed that EI10 is more reactive (or compatible) with Vectra B, whereas BI10 is more compatible with Ultem. The effect of compatibilizer structures on the ternary Ultem/Vectra B/PEsI blends was also studied by thermal behavior, Theological properties, and mechanical properties. These results showed that BI10, more compatible with Ultem matrix, acts as a better compatibilizer in a ternary Ultem/Vectra B/PEsI blend system than EI10, more compatible with Vectra B phase. The optimum level of the compatibilzers turned out to be about 1-2 wt% for the blend systems.