| Abstract
| - Polymer adhesion between two immiscible polymers is usually poor because there is little interpenetration of onepolymer into the other at the interface. Increasing the width of the interfacial zone can enhance adhesion and mechanicalproperties. In principle, this can be accomplished by exposing heterogeneous polymer materials to a high-pressurefluid. The fluid can act as a common solvent and promote interpenetration. It also increases chain mobility at theinterface, which helps to promote “welding” of the two polymers. A combination of the gradient theory of inhomogeneoussystems and the Sanchez−Lacombe equation of state was used to investigate this phenomenon, especially the effectof the high compressibility of supercritical (SC) fluid on the compatibilization of two incompatible polymers. Wecalculate the interfacial density profile, interfacial thickness, and interfacial tension between the two polymers withand without the SC fluid. We find that the interfacial tension is decreased and the interfacial thickness is increasedwith high-pressure SC fluid for the ternary systems we have investigated. As the critical point is approached and theSC compressibility becomes large, no enhancement or deleterious effects on compatibilization were observed.
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