STRUCTURE-PROPERTY RELATIONSHIPS IN POLYURETHANE POLY(STYRENE-CO-ACRYLONITRILE) BLENDS

Blends of thermoplastic polyurethane (TPU) and poly(styrene-co-acrylon itrile) (SAN) (34% acrylonitrile and 24% acrylonitrile) and polyuretha ne ionomer (PUI) with SAN (34% acrylonitrile) were prepared in the mel t. The structural properties and morphology of the blends were investi gated. TPU and SAN blends were immiscible in the composition range 30- 70 wt % of TPU or SAN. In TPU-rich blends, SAN propagates the separati on of hard and soft segments in TPU. In SAN-rich blends, the interacti on stage depends on acrylonitrile contents. SEM measurements showed th at the blends of TPU/SAN were fine dispersions and clearly showed a co ntinuous and disperse phase, whereas the morphology of the PUI/SAN ble nds were different. (C) 1993 John Wiley & Sons, Inc.