초록
The structure formation and the changes of mechanical properties in the course of annealing and hot-drawing process of an unoriented amorphous poly(ethylene 2,6-naphthalene dicarboxylate) (PEN) films were investigate using WAXD, DSC, Rheovibron, and etc. The PEN films were annealed at 120, 150, 180, 210, and 24$0^{\circ}C$ and drawn up to maximum drawable ratios at various drawing rates of 100, 200, 300, and 600 %/min and various temperatures of 100, 120, and 15$0^{\circ}C$. The results are as follows: (1) In the development of crystalline structure characterized by WAXD, the annealed PEN films have an intensive increase in the diffraction peak of (010) plane, but the hot-drawn samples have a high increase in the diffraction intensity of (110) plane caused by increasing orientation naphthalene ring. (2) In dynamic viscoelastic behavior, the amorphous dispersion showed at higher temperatures of 50~6$0^{\circ}C$ than $T_{g}$, and the drawing below $T_{g}$ produced an $\alpha$$_2$-dispersion due to an inhomogeneous taut structure. (3) PEN films drawn at 15$0^{\circ}C$ and at lower drawing rates had an isotropic-like transparency in spite of anistropic uniaxial drawing.
