Abstract
The crystallinity, crystallite size, orientation factor, loss modulus, and tan $\delta$ of P.E.T. films which had drawn at different temperature (72$^{\circ}C$, 79$^{\circ}C$) and then annealed at various temperature (150$^{\circ}$, 180$^{\circ}$, 21$0^{\circ}C$) and time (2.5, 10, 30min) were measured by density gradient, WAXD and dynamic viscoelasity test. The degree of crystallinty of P.E.T. film drawn at 72$^{\circ}C$ was similiar to that of 79$^{\circ}C$ in the case of 15$0^{\circ}C$, and 18$0^{\circ}C$ annealing however, it was significantly increased in the case of drawing at 72$^{\circ}C$ and annealing at 21$0^{\circ}C$. The crystallite size and the orientation factor of P.E.T. film having Drawn at 72$^{\circ}C$ were much larger than those of 79$^{\circ}C$, in particular, this tendency was quite evident in the orientation factor. It was found that the order of amorphous molecular chain in the case of 72$^{\circ}C$ drawing was better order than that of 79$^{\circ}C$, which was much remarkable at the heat treatments with low temperature. Those results can be explained by so called the super draw phenememon in the case of draw temperature of 79$^{\circ}C$.