DYNAMIC SCATTERING PROPERTIES OF MIXTURES OF CYCLIC AND LINEAR HOMOPOLYMERS AND COPOLYMERS

The dynamic scattering properties of mixtures of cyclic copolymers and homopolymers are discussed. These properties are compared with those characterizing linear chain mixtures in similar conditions. The differ ences between cyclic and linear chains are introduced through the form factors only. The interaction parameter between different monomer spe cies are assumed to be the same whether they belong to cyclic or linea r chains. The dynamical model is based upon a generalization of the ra ndom phase approximation neglecting hydrodynamic interaction and mode coupling effects. Despite these simplifications, substantial differenc es are found in the dynamics of mixtures containing cyclic copolymers and homopolymers when compared to those of linear chain systems in sim ilar conditions of temperature, concentration, and molecular weight. ( C) 1997 John Wiley & Sons, Inc.