Drawing and Heat-treatment of Poly(1, 3, 4-oxadiazole2, 5-diy1-1, 4-phenyleneiminocarbonyl-1, 3-phenylenecarbonylimino1, 4-phenylene) Film

Abstract

Poly(1, 3, 4-oxadiazole-2, 5-diyl-1, 4-phenyleneiminocarbonyl-1, 3-phenylenecarbonylimino-1, 4-phenylene) was prepared by a low-temperature solution polycondensation using N, Ndimethylacetamide as an organic solvent.
It was difficult to enhance the mechanical properties of these polymer films by cold and heat drawing. Therefore, the films were drawn in a N, N-dimethylformamide/H₂O mixture (60: 40, v/v) at 60°C and then heat-treated under a tension. The values of the Young's modulus and the strength at break of 3-fold drawn and heat-treated films (sample [7])were 13.0×10¹⁰ dyn/cm2 and 54.9 kg/mm2, respectively. These values are about 10.8 and 9.0 times as large as those of undrawn films. The values of the Young's modulus and the strength at break were decreased to 10.7×10¹⁰dyn/cm2 and 39.5 kg/mm2 after 2 hoursheataging at 350°C in air. This result showed the high-temperature durability of the drawn and heat-treated materials.