Polymerization of 4,4 '-(hexafluoroisopropylidene)-N,N '-bis(phthaloyl-L-leucine) diacid chloride with aromatic diamines by microwave irradiation

A new facile and rapid polycondensation reaction of 4,4'-(hexafluoroisoprop ylidene)-N,N'-bis(phthaloyl-L-leucine) diacid chloride (1) with several aro matic diamines, including benzidine (2a), 4,4'-diaminodiphenyl methane (2b) , 1,5-diaminoanthraquinone (2c), 4,4'-sulfonyldianiline (2d), 3,3'-diaminob enzophenone (2e), P-phenylenediamine (2f), 2,6-diaminopyridine (2g), 4,4' - diaminobenzophenone (2h), 2,4-diaminotoluene (2i), and 4,4'-diaminodiphenyl ether (2j), was developed with a domestic microwave oven in the presence of a small amount of a polar organic medium such as o-cresol. The polymerizat ion reactions proceeded rapidly compared to conventional solution polyconde nsation and finished within 12 min, producing a series of optically active poly(amide-imide)s with quantitative yields and high inherent viscosities o f 0.50-1.93 dL/g. All of the polymers were fully characterized by In, eleme ntal analyses, and specific rotation. Some structural characterization and physical properties of these optically active poly(amide-imide)s are report ed. (C) 2000 John Wiley & Sons, Inc.