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Flow birefringence and conformational characteristics of polyamide hydrazide molecules in dimethylsulphoxide

✍ Scribed by V.N. Tsvetkov; N.V. Pogodina; L.V. Starchenko

Publisher: Elsevier Science
Year: 1983
Tongue: English
Weight: 259 KB
Volume: 19
Category: Article
ISSN: 0014-3057
DOI: 10.1016/0014-3057(83)90156-8

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✦ Synopsis

Flow birefringence (FB) and intrinsic viscosity of 19 samples of aromatic polyamide hydrazide (PAH) in dimethylsulphoxide (DMS), previously characterized by their weight-average molecular weights by the light scattering method, have been investigated. The molecular-weight dependence of reduced birefringence according to theory [12] was used to determine the optical anisotropy of a monomer unit Aa = (200 + 20) 10 -25 cm 3 and the length of the Kuhn segment A = (250 + 30)A of PAH molecules. The second independent evaluation of rigidity of the PAH chain A = (240 + 30) A was obtained according to the theory of rotational friction of rigid wormlike chains by using the coefficients of rotational diffusion of PAH molecules determined from the characteristic values of orientation angles of FB. The value of rigidity of the PAH chain obtained by this method is in good agreement with the data on molecular dimensions obtained by light scattering.

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