ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Zero-average contrast small angle neutron scattering measurements have been performed on an 11%(w/w) nematic aramid polymer (PPTA) solution in concentrated sulphuric acid. The radii of gyration parallel and perpendicular to the director were determined to be 250 and 70 Å, respectively, at room temperature. In addition, the temperature dependence of the radii of gyration was investigated. The values for the radii of gyration are compared to a worm-like path model for the polymer chain statistics where the segment orientation is described using a Maier–Saupe-type orientational distribution function. From this analysis, it is found that the persistence length of the aramid molecules is the same in the nematic phase as in a dilute isotropic phase, about 290 Å. We conclude that there is no effect of the nematic environment on the polymer chain statistics in this main chain polymer solution. As a consequence, the nematic phase of aramid solutions is expected to contain polymer chains with a substantial number of hairpin defects. © 1998 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.477382
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