Abstract
Poly[oxy-1,4-phenylenecarbonylimino (2-chloro-5-methyl-1,4-phenylene) iminocarbonyl-1,4-phenylene] (P-1) was prepared by the low-temperature solution polycondensation of 2-chloro-5-methyl-p-phenylenediamine with bis (4-chloroformylphenyl) ether in 1-methyl-2-pyrrolidinone (NMP). The inherent viscosity of P-1 was 1.77 dL/g in sulfuric acid (0.5g/100mL, 25°C). In order to enhance the tensile properties of P-1 film, the film was drawn in a N,N'-dimethylacetamide (DMA) /water mixture (80 : 20, v/v, 50°C) and subsequently heat-treated under tension in nitrogen atmosphere, the temperature being raised from room temperature to 300°C at a heating rate of 15°C/min. The tensile strength (T), elongation (E), and tensile modulus (M) of the drawn and heat-treated film were 1.2 GPa, 13.9%, and 15 GPa, respectively. These values changed to 0.82 GPa (T), 6.59% (E), and 11 GPa (M) after 2 hours of aging at 300°C under release condition in air. After 2 hours of aging at 300°C under condition of constant length, the values changed to 1.1 GPa, 13.7%, and 15 GPa, respectively. The results show that the drawn and heat-treated Aramid films have high-temperature durability.
