ON THE DYNAMIC SCATTERING OF LINEAR AND CYCLIC COPOLYMERS IN SOLUTION

In this paper, a comparative study of the dynamic scattering propertie s of some linear and cyclic copolymers in solution is presented. This investigation is prompted by the recent elastic and quasielastic light scattering measurements reported by Amis and co-workers on polystyren e-polydimethylsiloxane cyclic diblock copolymers and their linear trib lock counterpart. A formalism is presented which could provide a theor etical framework for the analysis of some aspects of these data. The m odel predicts that two relaxation modes characterize the dynamics of b oth the cyclic diblock and the linear triblock copolymers. The amplitu des and decay rates of these relaxation modes are investigated as a fu nction of the polymer architecture, the concentration, and the scatter ing wavevector. Questions related with phase transitions via aggregati on or micellar formation are not addressed here.