AbstractTo prepare high‐modulus and high‐strength PET fiber, a new method using zone drawing and zone annealing has been studied. The apparatus used for this method is the usual tensile tester equipped with a band heater 2 mm wide and a sample holder which can apply a high tension to the fiber. The experimental procedure consists of two stages: zone drawing and zone annealing. The zone drawing was done on the original as‐spun fiber in order to produce a fiber with as high an orientation and as low a crystallinity as possible. The zone‐drawn fiber was subsequently zone annealed under high tension by moving the band heater from one end to the other of the fiber at a temperature above the crystallization temperature at a considerably low moving speed. In spite of the simple apparatus and procedure, Young's modulus of the fiber obtained was 19.4 × 1010dyn/cm2, which is comparable to the maximum value of the high‐tenacity PET filament commercially available. In order to elucidate the change in the superstructure with zone drawing or zone annealing, optical, x‐ray, IR, DSC, and dynamic mechanical measurements were performed. It is suggested that the zone‐annealed fiber consists of almost perfectly oriented crystallites and fully extended am
展开▼
