This work is part of a programme concerned with the effects of plasticizer type, and involves the relationships between PVC/plasticizer properties and the processing characteristics of the PVC compound. This study evaluates the mechanical properties of PVC/TPU blends and the alternative compounds PVC/di-isodecylphthalate (DIDP) and compares them with the traditional formulation PVC/DOP. All of the blends were prepared in a twin screw extruder. Their mechanical behaviour is compared under different processing conditions.