Microwave-assisted synthesis of optically active poly(amide imide)s derived from diacid chloride containing epiclon and L-leucine with aromatic diamines

Epiclon [3a,4,5,7a-tetrahydro-7-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-1,3-isobenzofurandione or 5-(2,5-dioxotetrahydrofurfuryl)-3-methyl-3-cyclohexyl-1,2-dicarboxylic acid anhydride] was reacted with L-leucine in acetic acid, and the resulting imide acid (3) was obtained in a high yield. The diacid chloride (4) was obtained from its diacid derivative 3 by a reaction with oxalyl chloride in dry carbon tetrachloride. The polycondensation reaction of 4 with several aromatic diamines, such as 4,4'-sulfonyl-dianiline, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylether, p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, and 1,5-diaminonaphthalene, was developed with a domestic microwave oven in the presence of a small amount of a polar organic medium such as N-methylpyrrolidone. The polymerization reactions were also performed with two other methods: low-temperature solution polycondensation in the presence of trimethylsilyl chloride and reflux conditions. A series of optically active poly(amide imide)s with moderate yields and inherent viscosities of 0.12-0.19 dL/g were obtained. All of these polymers were fully characterized by IR, elemental analysis, and specific rotation techniques. Some structural characterizations and physical properties of these optically active poly(amide imide)s are reported. (C) 2003 Wiley Periodicals, Inc.