INTERFACIAL PROPERTY DETERMINATION FOR IMMISCIBLE POLYMER BLENDS - A MODEL SYSTEM OF POLYCARBONATE POLY(ETHYLENE TEREPHTHALATE)/

A model system, a tri-layer of polycarbonate/poly(ethylene terephthala te)/polycarbonate, was used in this study to investigate the interfaci al properties of an immiscible polymer blend system. The model system was compression molded and quenched in three different media: ice, wat er, and hot water. The interfacial properties of interest were the thr ough-thickness residual stress profiles and the interfacial strength. A method of estimating the interfacial strength of an immiscible polym er blend was also proposed, enabling the prediction of failure. The me thod was based on a single-notch 4-point bending test. The load at whi ch failure occurred was then analyzed using finite element stress anal ysis to resolve the interfacial stress, i.e., the strength of the inte rface.