Title: Phase Segregation in Ternary Polymer Blends
Speaker: Professor Monica Olvera de la Cruz
Speaker Info: Northwestern U.
Special Note: For students there will be an informal introduction at 1:30 in M416
Most commercial polymers are multi-component mixtures. Since polymer blends are strongly incompatible, non- homogeneous microstructures result upon mixing. The dynamics of A-B-C incompressible ternary polymer blends decomposing into two and three phases were studied by solving the coupled non-linear spinodal decomposition equations. During the decomposition, between any two phase domains rich in component I and J, the third component K adsorbes in the I-J interphase to decrease the interfacial energy. The coarsening phenomena is strongly dependent on the topology of the non-equilibrium microstructure (i.e., on the degree of adsorption). The adorption in system unstable to the formation of two majority phases rich in components A and B, and stable or metastable to the formation of a third phase rich in the C minority component was anlayzed in great detail by minimizing the specific interfacial energy and by finding the steady-state solution of the spinodal decomposition equations. The adsorption in ternary alloys was also analyzed.Date: Friday, February 27, 1998