Properties of PET-PEN blends produced by extrusion and injection blow-molding

In this work, blends made of polyethylene terephthalate (PET) and polyethylene 2,6 naphthalene dicarboxylate (PEN) were prepared by melt extrusion processed at several temperatures and residence times. The blends with composition up to 20 wt % PEN were characterized with regard to their degree of transesterification and their rheological properties. Subsequently, bottles were produced by injection-stretch blow-molding and their mechanical properties were measured. It was found that improved PET-PEN blends were produced at 270 degrees C with.a PET content of 15 and 20 wt % and residence time processing of 4 minutes. Both blends present a low degree of transesterification, block conformations, high shear viscosity and improved tensile properties.