| Abstract: | Truncated, six-sided single crystals of a 10–16 linear polyester were grown from dilute solution in hexanol, deposited onto Mylar film, and uniaxially deformed at room temperature. For elongations below 10%, the crystals deform uniformly; however, above 20% elongation many cracks spanned by fibrils of 300 Å diameter develop approximately normal to the applied stress direction. Depending on the position of the crystal relative to the draw direction, lateral buckling pleats and cleavage cracks can also occur. Collapse of the nonplanar crystals onto the substrate with a resulting nonuniform adherence of the crystal influences the deformation. The deformation morphology is compared to that of truncated sixfold sector polyethylene crystals. Most notably, in contrast to polyethylene, {010} fold sectors do not deform differently from {110} fold sectors and phase boundaries between {110} and {010} fold sectors do not fracture easily. |
