Polyhexamethylene terephthalamide (nylon 6-T), wet-spun from concentrated sulfuric acid, yields poorly or moderately oriented filaments, depending on the amount of stretch during spinning. Such fibers cannot properly be called amorphous, since they characteristically show a "line-lattice" or one-dimensional order along the chain direction. There appear to be several alternate ways in which the chains pack together laterally in the spun fibers, and hot-drawn fibers with full three- dimensional crystallinity exhibit polymorphism. The birefringence and certain features of the x-ray pattern correlate with tenacity in both spun and drawn fibers.
Bunn, C.W. and Garner, E.V., Nylon Filaments: Crystal Structure, Proc. Roy. Soc.189A, 39 (1947); Holmes, D.R., Bunn, C.W. and Smith, D.J., The Crystal Structure of Polycaproamide: Nylon 6, J. Polymer Sci.17, 159-177 (1955).
2.
Daubeny, R.P. , Bunn, C.W. and Brown, C.J., Crystal Structure of Polyethyleneterephthalate , Proc. Roy. Soc.226A, 531-542 (1954).
3.
Epstein, M.E. and Rosenthal, A.J., Spinning of Polyamides from Sulfuric Acid Solution. Polymer Solubility and Coagulation Mechanisms, Textile Res. J.36, 813-821 (1966).
4.
Quynn, R.G. and Steele, R., The Birefringence of Dacron Polyester Fiber, Textile Res. J.23, 258-259 (1953).
5.
Rosenthal, A.J. , TE1, An Index for Relating Fiber Tenacity and Elongation, Textile Res. J.36, 593-602 (1966).
6.
Statton, W.O. , Directional "Crystallization" of Polymers, Ann. N. Y. Acad. Sci.83, 27-36 (1959).
7.
Sprague, B.S. and Singleton, R.W., Fibers from Aromatic Polyamides, Textile Res. J.35, 999-1008 (1965).
8.
U. S. Patent 3,154,612, Oct. 27, 1964; U. S. Patent 3,227,792, Jan. 4, 1966; U. S. Patent 3,227,793, Jan. 4, 1966 (all to Celanese Corporation of America).
9.
Vogelsong, D.C. and Pearce, E.M., Polymorphism in Nylon 8, J. Polymer Sci.45, 546-547 (1960).
