Deformation processes in thin melt-cast films of high-density polyethylene: I. Experimental methods and deformation processes in the equatorial regions of spherulites

Selected area electron diffraction is described as a method for making quantitative studies of intralamellar deformation processes in micropherulitic structures. The technique is applied to characterize stress-induced twinning and phase transformations in the equatorial regions of spherulites in melt-cast spherulitie films after drawing while in contact with Mylar substrates. The sequence of deformation processes which occurs with increasing applied strain and with position in a spherulite has been identified, and is described in detail and compared with previously reported results obtained from experiments with single crystal and bulk forms of high-density polyethylene.