Experimental Study of Interfacial Slip Effect on the Rheological Behavior of PS/PMMA Blends

Rheological experiments in shear and uniaxial elongational flows have been carried out on a model immiscible blend made of PS and PMMA with various compositions. Experimental results showed a negative deviation behavior from the log-­additivity rule both in shear and elongation for blends having PS as the continuous phase. Such behavior can be attributed to the interfacial slip that results from a lack of entanglements and thus from the weak adhesion at the interface, as verified by Scanning Electron Microscopy observations. The obtained reduction in viscosity was compared to the predictions of Bousmina-­Palierne-­Utracki (1999) and Adhekari-­Goveas (2004) models. Addition of 1wt% of a block copolymer resulted in a partial suppression of the interfacial slip.