THE INFLUENCE OF POLYMER STRUCTURE AND COMPONENT RATIOS ON BLEND MISCIBILITY

The mean field, rigid lattice treatment as applied to polymer mixtures has been used to estimate segment-segment interaction parameters for a wide range of polymers. These parameters incorporate, without distin ction, contributions from non-combinatorial entropy effects, dispersio n forces and any specific interactions that operate in the polymer ble nd. Thus while these parameters can be used to predict successfully th e nature of the phases in untested polymer blends, structural effects may also play a role in determining miscibility, and these may have to be assessed individually. Examples of structural effects are describe d using chlorine-containing polymers and blends of copolymers with an anhydride ring attached in two different ways to the polymer chain. Th e extension of binary interaction parameters to the prediction of phas e behaviour in complex ternary copolymer blends and the effect on the phase behaviour of changing the component ratios in the blends, is als o illustrated.