Poly(butylene terephthalate)/high density polyethylene alloys. II. Mechanical properties and rheology

Alloys of poly(butylene terephthalate) (PBT) and high density polyethylene (HDPE) in 80 : 20 ratio were prepared using a polyethylene‐based ionomer as a compatibilizer. The effect of the addition of this compatibilizer on mechanical and rheological properties of the PBT/HDPE blends was examined. The mechanical properties studied were tensile, flexural, and impact properties as a function of ionomer content. Ultimate mechanical properties showed significant improvement on addition of ionomer. This has been attributed to an increase in the interfacial adhesion between the two phases in the presence of the compatibilizer. Rheological measurements showed that shear viscosity increased for the blend with the addition of the compatibilizer. An explanation for this behavior is presented on the basis of the theory of emulsions.