NEUTRON-SCATTERING STUDIES OF SYNDIOTACTIC POLYSTYRENE CRYSTALS

Neutron scattering experiments are reported on solution grown crystals of syndiotactic polystyrene (sPS) at small and large q, in order to i nvestigate the chain conformation within the lamellar crystals. From t he results in both the Guinier and the intermediate ranges, we come to the following conclusions: the chain folds in one or several sheet de pending on the molecular weight, comparison between measured and calcu lated intensity plots give strong indication that a is the fold direct ion. The statistical model recently built for the spatial arrangement of stems in a sheet-like structure is successful again, and demonstrat e a strong statistical preference for adjacent re-entry.