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Trifluoroacetylation of segmented polyurethanes

✍ Scribed by Zoran S. Petrović; Ljiljana Korugić-Perković

Publisher
Elsevier Science
Year
1989
Tongue
English
Weight
277 KB
Volume
25
Category
Article
ISSN
0014-3057

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✦ Synopsis

Trifluoroacetylation has been successfully applied to polyamides in order to obtain polymers soluble in aprotic solvents; trifluoroacetylation of polyurethanes was reported to be much slower. In this work, the results of a study of the effect of trifluoroacetic anhydride/NH molar ratio, reaction time and temperature on the degree of substitution of hydrogen in the urethane bond are described. The structure of three segmented polyetherurethanes was varied by varying the soft segment concentration from 20 to 80%. It was found that under severe conditions trifluoroacetylation could not be completed even after 20 days. Partially trifluoroacetylated polymers displayed low hydrolytic and thermal stability. The effect was more marked in polyurethanes with higher hard segment content.

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