Synthesis of novel optically active poly(ester imide)s by direct polycondensation reaction promoted by tosyl chloride in pyridine in the presence of N,N-dimethyformamide

摘要

4,4'-Hexafluoroisopropylidene-2,2-bis(phthalic acid anhydride) (1) was treated with L-methionine (2) in acetic acid and the resulting 4,4'-(hexafluoroisopropylidene)-N,N'-bis(phthaloyl-L-methionine) diacid (4) was obtained in high yields. 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 tosyl chloride (TsCl), pyridine (Py), and N,N-dimethylformamide (DMF). The reactions with TsCl were significantly promoted by controlling alcoholysis with diols, in the presence of catalytic amounts of DMF, to give a series of optically active poly(ester imide)s, (PEI)s, with good yield and moderate inherent viscosity ranging from 0.43 to 0.67 dL/g. The polycondensation reactions were significantly affected by the amounts of DMF, molar concentration of monomers, TsCl and Py, aging time, temperature, and reaction time. All of the aforementioned polymers were fully characterized by H-1 NMR, FTIR, elemental analysis, and specific rotation. Some structural characterization and physical properties of these optically active PEIs are reported. (c) 2006 Wiley Periodicals, Inc.