SCATTERING BY CYCLIC POLYMERS AND COPOLYMERS AT LARGE SCATTERING VECTORS

General formulae allowing the evaluation of the form factors of cyclic block copolymers are established and graphs for cyclic copolymers of the form (A-B)(N) are shown. When N is large, the linear and the cyclic copolymer have the same behaviour. It is possible to extend at large angle an analytical expression given for linear polymers. This allows to show that, in the study of transesterification by small-angle neutron scattering, one can neglect the effect of cycles.