DYNAMIC-MECHANICAL PROPERTIES OF POLY(VINYL CHLORIDE) AND POLYURETHANE CARBOXYLATE BLENDS

The miscibility of thermoplastic polyurethane elastomers (TPUs) with poly (vinyl chloride) (PVC) was studied. PVC blends with TPUs, prepared from 4,4'-diphenylmethane diisocyanate as diisocyanate, hydroxy-terminated poly(butylene adipate) (PBA) as the soft segment, and dimethylolpropionic acid as the chain extender carrying a latent anionic site for neutralization by triethylamine, showed a single glass transition temperature (T(g)), irrespective of neutralization of latent anionic sites of TPU. But in neutralized TPU/PVC blends, limited intimate segmental mixing was perceived from the mechanical properties observed. When hydroxy-terminated poly (propylene glycol) was used as the soft segment instead of hydroxy-terminated PBA, PVC/TPU blends showed two separate T(g)'s of PVC and TPU, irrespective of neutralization. (C) 1994 John Wiley & Sons, Inc.