Structural tomography of poly(methyl methacrylate) deformed by uniaxial compression

A special procedure for studying structural rearrangements in polymers under their uniaxial com- pression was proposed. A cylindrical polymer sample commonly used in deformation tests was composed of thin polymer layers. After deformation, this sample was disassembled into individual layers, and their structure and properties were examined (the structural tomography). As was shown for PMMA, this procedure allows one to gain new information concerning the deformation mechanism of a glassy polymer. Using the method of atomic force microscopy, contributions from bulk and surface components of the polymer structure upon uniax- ial compression were ascertained. In particular, upon annealing, the structural relaxation of the deformed glassy polymer was found to proceed in a complex way, thus revealing the two components of temperature-induced shrinkage: low-temperature (the surface component) and high-temperature (the bulk component).