Preparation and characterization of new thermally stable and optically active poly(ester-imide)s by direct polycondensation with thionyl chloride in pyridine

Abstract

4,4′-hexafluoroisopropylidene-2,2-bis-(phthalic acid anhydride) (1) was reacted with L-methionine (2) in acetic acid and the resulting N,N′–(4,4′-hexafluoroisopropylidenediphthaloyl)-bis-L-methionine (4) was obtained in high yield. The direct polycondensation reaction of this diacid with several aromatic diols such as bisphenol A (5a), phenolphthalein (5b), 1,4-dihydroxybenzene (5c), 4,4′-dihydroxydiphenyl sulfide (5d), 4,6-dihydroxypyrimidine (5e), 4,4′-dihydroxydiphenyl sulfone (5f) and 2,4′-dihydroxyacetophenone (5g) was carried out in a system of thionyl chloride and pyridine. Expecting that the reaction with thionyl chloride in pyridine might involve alternative intermediates different from an acyl chloride, the polycondensation at a higher temperature favorable for the reaction of the expected intermediate with nucleophiles was attempted, and a highly thermally stable poly(ester-imide) was obtained by carrying out the reaction at 80°C. All of the above polymers were fully characterized by 1H-NMR, 19F-NMR FT-IR spectroscopy, elemental analysis and specific rotation. Some structural characterization and physical properties of these optically active poly(ester- imide)s are reported. Copyright © 2006 John Wiley & Sons, Ltd.