Molecular Aggregation Structure of Notched Nylon 12 Film during Uniaxial Elongation

Abstract

Polarizing observation was carried out for nylon 12 (Ny12) films with a notch of ca. 0.2 mm length during uniaxial elongation. As the result, a ductile deformation behavior was detected, and a X-shaped area with higher retardation was observed around the notch extending to 45˚inclined direction to the uniaxial elongation direction. Moreover, during the uniaxial elongation, in-situ wide angled X-ray diffraction (WAXD) measurement were performed at various positions in the Ny12 film specimens. As a result, a crystal phase transition from γ-crystal to α-crystal seemed to occur in the region where higher retardations were observed. Since the intrinsic birefringence in α-crystal is higher than those in γ-crystal and amorphous phases, the increase in retardation can be caused by increase of α-crystalline fraction.