CHARACTERIZATION OF A LADDER POLYMER BY SMALL-ANGLE X-RAY AND NEUTRON-SCATTERING

An analysis of the conformation of a ribbon-type polymer in dilute sol ution is given. By combination of small-angle neutron scattering (SANS ) and small-angle X-ray scattering (SAXS) the effect of the finite dim ensions of the repeating units can be assessed separately. It is thus possible to evaluate the experimental data to yield the form factor of the corresponding infinitely thin chain. This form factor could be ev aluated for three samples differing in molecular weight and compared t o the theoretical expression furnished by Kholodenko (Macromolecules 1 993, 26, 4179). Good agreement for all molecular weights under conside ration here could be achieved. The analysis shows that the ribbon-type polymers under consideration here are wormlike chains with a persiste nce length of 6.5 nm.