2004 -02 -18
10 :15 at ML J 21

Relaxation and breakup phenomena in melts of PS/PMMA blends after equibiaxial elongation

Ulrich Handge

Polymer Physics, Dept. Materials Science, ETH Zurich

The end-use properties of binary blends of immiscible polymers are strongly influenced by the blend morphology. Therefore understanding the processes which lead to different types of morphology during blending is crucial in order to control the end-use properties. In this study, we focus on melts of polystyrene (PS)/poly(methyl methacrylate) (PMMA) blends and experimentally investigate the relaxation of an equibiaxially elongated PS drop in a PMMA matrix. If the PS drop has been extended to a large stretch ratio during equibiaxial elongation, it attains a disclike shape. In subsequent relaxation, the PS drop breaks up driven by the interfacial tension between PS and PMMA. In this talk, we present the results of our microscopic investigation of the evolution of the drop shape during relaxation. Our investigations reveal that holes are formed in the elongated drop which finally lead to the disintegration of the PS drop.