Ionomer blends: Morphology and mechanical properties

Polymer blends, having one component as an ionomer, can develop an interesting combination of mechanical properties. These properties give such blends some specific advantages as compared to non-ionic homopolymers. Primary attention is given to blends involving an ionomer and the ionomer precursor polymer. In such blends, synergistic effects can occur in several of the mechanical properties, such as modulus, strength and fracture energy. The enhanced mechanical properties, which occur for relatively low concentrations of the ionomer in the blends, are well above values predicted by the rule of mixtures. This behavior is attributed to the presence in the ionomer component of a higher chain entanglement density and to good adhesion between the dispersed ionomer particles and the polymer matrix. Some discussion, with examples, is also given of other blends having an ionomer as one component and of blends in which a small amount of ionomer is added in order to enhance the miscibility of two otherwise incompatible polymers.