Miscibility and shape memory property of poly(vinyl chloride)/thermoplastic polyurethane blends

The miscibility and the shape memory effect of PVC blends with segmented th ermoplastic polyurethanes (TPUs), synthesized from diol-terminated polycapr olactone (PCL), hexamethylene diisocyanate, 4,4'-dihydroxy biphenyl, were s tudied. PVC was miscible with PCL segment in TPU and the glass transition t emperature of this miscible amorphous domain varied smoothly with compositi on. When PVC was blended with TPU by the weight ratio of 8/2, the hysterisi s in repeated cyclic tensile test was reduced compared with PVC. However, i n 6/4 blends, unrecoverable permanent deformation was increased compared wi th PVC. Dynamic mechanical properties were examined to explain these result s. (C) 2001 Kluwer Academic Publishers.