A Double-Tilt Small Angle Neutron Scattering Experiment on Deformed Poly Mer Systems

A double rotation goniometer has been mounted in the neutron beam in order to characterize the molecular deformation in polymers subjected to various strain conditions.The results provide a direct verification of the fiber symmetry in solid state coextruded polymethylmethacrylate (PMMA) and polypropylene (PP) homopolymers.In the case of the shear banding phenomenon, we have been able to test the validity of the simple shear assumption: it also provides a direct estimate of the finite shear strain involved in the process. As a last illustration ofthe method, we also consider the biaxial deformation of PP and PMMA squeezed under various temperature and strain-rate conditions.