ISSN:
0032-3888
Schlagwort(e):
Chemistry
;
Chemical Engineering
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Maschinenbau
,
Physik
Notizen:
Transmitted light intensities were measured by means of the polarized light technique for the nematic liquid crystal phase of racemic poly(γ-benzyl glutamate) (PBG) in m-cresol at 25°C after cessation of steady flow at shear rates ranging from 0.2 to 110 s-1. Weight-average molecular weights of PBG used were 1.5, 2.1, and 2.6 × 105, while the concentrations varied between 20, 30, and 40 wt percent. Transmitted light intensities with crossed and parallel polarizers, Ix and I|, show wavy changes with time after cessation of steady flow, indicating the retardation decreases with time. An attempt was made to explain experimental results on the basis of a simple model, in which not only relaxation of molecular orientation but also effects of the wall and disclination were taken into account.
Zusätzliches Material:
16 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/pen.760240510
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