ISSN:
0025-116X
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
As a part of studies on wholly aromatic polyamides containing bridged biphenylylene groups, poly(3,8-phenanthridinonediyl terephthalamide) (DAP-T) was prepared from 3,8-diaminophenanthridinone and terephthaloyl chloride. The solutions of DAP-T samples in high concentration sulfuric acid exhibited optically different phases, depending on temperature and concentration, like those of poly(1,4-phenylene terephthalamide) (PPD-T). The phase diagram of the DAP-T-99,0% H2SO4 system was established and compared with that of the PPD-T-99,0% H2SO4 system. Both were essentially similar. The flow of high concentration dopes of DAP-T and PPD-T through spinneret holes showed non-Newtonian characteristics. The liquid-crystalline solutions of DAP-T in 99,0% sulfuric acid were spun into fibers using water as a coagulant. The tensile strength and initial modulus increased with increasing degree of stretching between spinneret and collection roller. The annealing of fibers caused an increase in tenacity and modulus, and a tensile strength of 25 g/den and an initial modulus of 1 000 g/den could be reached. Both spun fibers and annealed fibers showed x-ray diffraction patterns displaying distinct layer line streaks, from which the fiber period was estimated to be 17,2 Å. This agreed with the repeat distance in the direction of molecular axis calculated on the basis of extended chains with trans-conformation.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1982.021830213
