Structures and physical properties of poly(ethylene 2,6-naphthalate)/liquid crystalline polymer blends

Abstract

Poly(ethylene 2,6-naphthalate) (PEN) and liquid crystalline polymer (LCP) blend fibers were prepared by reactive extrusion. Structures and physical properties of PEN/LCP blends were investigated with respect to blend ratio and transesterification reaction. Orientation, modulus, and thermal expansion coefficient of the PEN/LCP blend fibers were improved by increasing the draw ratio, Interfacial adhesion between PEN and LCP phases was enhanced when the blends were processed with dibutyltindilaurate (DBTDL) as reactive catalyst to promote transesterification. Optimum amount of the reaction catalyst turned out to be about 500 ppm in 75/25 PEN/LCP blend systems. Enhanced compatibility between two immiscible polymers resulted in decrease of dissipation energy in interfacial region. Thus tan delta value decreased. As a result of transesterification, density and reduction of thermal expansion coefficients of PEN/LCP blends increased by closer chain packing and higher interactions.