Miscibility behaviour of blends of a thermoplastic polyester polyurethane with vinyl polymers

A method based on the intrinsic viscosities of transfer has been used to pr edict miscibility of polymer blends. This method has been applied to study the change in the phase behaviour of a microphase separated polyester polyu rethane (PSPU) on blending with polyvinyl chloride (PVC), polyvinyl acetate (PVAc) and a vinyl chloride-vinyl acetate copolymer (VCVAc). The PVC/PSPU blends are found to exhibit complete miscibility over the entire compositio n range. PVAc/PSPU blends show immiscibility while VCVAc/PSPU blends show p artial miscibility. Thermal analysis and scanning electron microscopic stud ies of the blend films have confirmed the results evaluated on the basis of the viscosity method.