In situ Molecular Aggregation Structure Analyses on Glassy Polymers during Mechanical Deformation*

Poly (methyl methacrylate) (PMMA) and polycarbonate (PC) were chosen as a glassy polymer. Molecular aggregation structure and stretching properties of these glassy films were investigated by polarized high-speed camera observation and synchrotron X-ray wide-angle and small-angle scattering techniques during uniaxial and bulge deformation processes.
M_n of PC was 30k. M_n of PMMAs were 70k and 1.2M. During both uniaxial and bulge deformation processes, PMMA-70k showed brittle nature, and PC and PMMA-1.2 M showed ductile property. In situ wide-angle X-ray scattering measurement revealed that increase in interchain distance during bulge deformation. Also, polarized high-speed camera observation revealed that PMMA-1.2M showed a wrinkle structure. This structure must be related to emergence of ductile property of PMMA-1.2M.