Uniaxially oriented poly(vinyl chloride) films drawn at 90, 100 and ll0°C to draw ratios in the range 1.5 3.5 have been investigated using i.r. spectroscopy and refractive index measurements. Their 10 s isochronal extensional creep moduli and dynamic tensile moduli have also been measured. One-way drawn films with draw ratios in the range 1.56 x 1-2.56 x 1 and simultaneously and sequentially two-way drawn films with draw ratios in the range 1.46 x 1.46-1.79 x 1.79 have been investigated using refractive index measurements and i.r. spectroscopy. These films were drawn at 85 and 95°C. Thermal analysis of the drawn samples showed that the uniaxially drawn films were drawn at temperatures well above their final glass transition temperatures, whereas the one-way and two-way drawn films were drawn close to their glass transition temperatures. The results show that the crystallites are more highly oriented than the amorphous chains and that one-way drawn samples depart slightly from uniaxiality. No significant difference in orientation was found between simultaneously and sequentially two-way drawn samples. It was shown that the i.r. peak at 613 cm 1, attributed to short syndiotactic segments, could be used to characterize the orientation of the amorphous chains. The elastic moduli of the uniaxially drawn samples were found to depend on orientation in a similar way to that previously reported
Посилання на статтю:
Molecular orientation in uniaxial, one-way and two-way drawn poly(vinyl chloride) films / I. Karacan, D. I. Bower* and I. M. Ward // Polymer. – 1994. – Vol 35. – P. 3411-3422.