Polystyrene/Hyperbranched Polyester Blends and Reactive Polystyrene/ Hyperbranched Polyester Blends

Newly developed hyperbranched polyols (HBP) possess a highly branched three-dimensional structure and a high density of functional end groups relative to conventional linear or branched polymer molecules. Due to their inherent low viscosity and versatile end group chemistry, these materials are attractive as polymer blend modifiers for improved processing as well as improved properties due to reactive compatibilization. In this work, the incorporation of HBPs in thermoplastic blends was investigated. Several volume fractions of hydroxyl functionalized hyperbranched polyesters were melt blended with nonreactive polystyrene (PS) and two types of reactive styrene maleic anhydride (SMA). Rheological data proved that HBPs are effective processing aids in both nonreactive and reactive blends. Studies including microscopy, thermal analysis, dynamic mechanical analysis, and Fourier transform infrared (FTIR) indicate that PS and HBP form an immiscible blend while SMA and HBP form compatibilized blends. The degree of compatibilization in the blends was found to increase with SMA reactivity.Army Research Lab Aberdeen Proving Ground is the author of 'Polystyrene/Hyperbranched Polyester Blends and Reactive Polystyrene/ Hyperbranched Polyester Blends', published 1999 under ISBN 9781423554042 and ISBN 1423554043.