ON THE FLEXIBILITY OF CYCLOCHAIN POLYMERS

Conformational parameters for a wide variety of aromatic cyclochain polymers have been computed assuming free rotation about virtual bonds. The flexibility with free rotation is shown to be determined by the geometry of the repeat unit and can vary over a wide range (15-1500 angstrom). Experimental values of the Kuhn segment length A are calculated from literature data on the hydrodynamic behavior of polymeric macromolecules of this class in solution. For most polymers A(fr) for free rotation is equal to the experimental A(exp), and hindered rotation is mainly due to bulky substituents. (C) 1993 John Wiley & Sons, Inc.