Structure development in biaxial stretching of cast polyamide 11

The development of crystallinity and polymer chain orientation in the biaxial stretching process of cast polyamide 11 (PA11) films was investigated. The characterization of the stretched films was done with birefringence measurements, wide angle X-ray diffraction (WAXS), differential scanning calorimetry (DSC) and small angle X-ray scattering (SAXS). Biaxial orientation factors were represented in a White-Spruiell orientation isosceles triangle. As distinct from polyamide 6 (PA6) and polyamide 612 (PA612), DSC scanning of as-cast PA11 film were crystalline and exhibited a little change in crystallinity by aging at room condition. The glass transition temperature (T-g) increased during aging. PA11 highly biaxially stretched in an elevated temperature had monoclinic and triclinic crystals, respectively. The dimensions of the crystals were changed with the stretching conditions.