MECHANICAL-PROPERTIES AND MORPHOLOGY OF THERMOPLASTIC POLYURETHANE ELASTOMER WITH POL(VINYLIDENE FLUORIDE) BLENDS

A study on blends of thermoplastic polyurethane elastomer (TPU)/poly(v inylidene fluoride) (PVDF) is described. This investigation focused on the effects that PVDF has on the mechanical behaviors and morphologic al characteristics of the blends. Basic thermodynamic and structural c onsiderations were applied to predict the blend miscibility. It was fo und that addition of PVDF disrupted the intermolecular chain interacti ons in TPU, resulting in lowering of mechanical properties in the blen ds. Our results showed that the 50/50 blend has the lowest mechanical strength. At higher levels of PVDF (>50%), the mechanical strength inc reased proportionally to PVDF. It was also found that both the breakin g strain and the energy at break of these blends decreased with increa sed PVDF content. The lowering of the mechanical properties in the ble nds could be attributed to the formation of layered structures caused by the immiscibility of the polymers. It was concluded that TPU/PVDF b lends were incompatible at all compositions. (C) 1996 John Wiley & Son s, Inc.