1987 Volume 43 Issue 12 Pages 627-636
The X-ray diffraction and infrared spectra have been measured for the aramide copolymer fibers (M50) produced by the condensation polymerization between p-phenylenediamine/3, 4′-diaminodiphenylether equimolar mixture and terephthalic chloride. The X-ray diagram of the unannealed fiber is diffuse and apparently assumed to be an overlap of the patterns of the homopolymers of each component 1 and 2 with poor crystallinity. After annealing at 400°C, where the large weight loss was observed, the X-ray and infrared patterns were found to coincide essentially with those of the homopolymer 1 i.e., poly-p-phenylene terephthalamide (PPTA). The X-ray and infrared spectra of the homopolymer 2 (M100) was found to change into the structureless broad pattern after annealed at 400°C. These experimental results indicate that (1) some crystalline domains consisting only of one component (1 or 2) are existent in the original copolymer sample and (2) the heat treatment above 400°C degrades chemically the component 2 and then only the component 1 remains left, giving a relatively high-crystalline pattern of PPTA. The sample was found to change into the carbon fiber by annealing above 500°C.
