ABSTRACT
Blending of polymers has resulted in the development of polymeric materials with desirable combinations of properties. In most cases, simple blending will not result in the attainment of desirable combinations of properties because of some inherent problems. Frequently, the two polymers are thermodynamically immiscible and the product will not exhibit homogeneity. Often a low level of inhomogeneity is preferred as both the components can retain their identity in the blend and thereby contribute synergistically toward blend properties. However, the interfacial situation in an immiscible blend is very critical in determining the blend properties. A typical incompatible blend exhibits high interfacial tension and poor adhesion between the phases. The high interfacial tension results in poor dispersion during mixing and the subsequent lack of stability during later processing or use. Often such blends show poor mechanical properties, particularly those related to ductility, that can preclude their commercial utilization. Moreover, the weak interfacial interaction in these blends leads to premature failure under stress as a result of the usual crack opening mechanism [1].
