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  • Author or Editor: I. Andreeva x
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Abstract  

Flow birefringence (FB) has been investigated in solutions of products of hydrolytic degradation of poly(naphthoyleneimide benzimidazole) (PNIB) in 96% sulphuric acid PNIB solutions have previously been subjected to heating at various temperatures from 65 to 120°C and then investigated at 22°C by FB and viscometry. A monotonic decrease in intrinsic viscosity and the molecular weightM of thermal degradation products with increasing degradation temperature was detected. At the same time, the shear optical coefficients in series of products with decreasingM first increases and then, at treatment temperatures exceeding 90°C, decreases with decreasing [ν] in accordance with decreasingM of the product. Possible reasons for the detected anomaly have been discussed.

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Abstract  

The extraction of Y(III) using molten C7−C9 monocarboxylic acids and stearic acid with paraffin was studied. The optimal conditions for the extraction as well as the effect of different factors on the process were established. The method can be used for the concentration of Y(III) from dilute solutions with subsequent X-ray fluorescence determination in the solid extractants.

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