Synthesis of New Optically Active Poly(amide-imide)s Containing EPICLON and L-Phenylalanine in the Main Chain by Microwave Irradiation and Classical Heating Shadpour Mallakpour,* Mohammad Reza Zamanlou Organic Polymer Chemistry Research Laboratory, College of Chemistry, Isfahan University of Technology, Isfahan, 84156, I.R. Iran Received 19 June 2003; accepted 5 September 2003 ABSTRACT: 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] (1) was reacted with l- phenylalanine (2) in acetic acid, and the resulting amic acid was refluxed under a Dean-Stark system with benzene, which produced diacid (3) in high yield. Compound (3) was converted to the diacid chloride (4) by reaction with oxalyl chloride in dry carbon tetrachloride. The polycondensation reaction of this diacid chloride (4) with several aromatic diamines such as 4,4'-sulfonyldianiline (5a), 4,4'-diaminodi- phenylmethane (5b), 4,4'-diaminodiphenylether (5c), 1,4- phenylenediamine (5d), 1,3-phenylenediamine (5e), 2,4- diaminotoluene (5f), and 1,5-diaminonaphthalene (5g) was developed by using a domestic microwave oven in the pres- ence of a small amount of a polar organic medium such as N-methylpyrrolidone (NMP). The polymerization reactions were also performed under two different classical heating methods: low temperature solution polycondensation in the presence of trimethylsilyl chloride, and high temperature polymerization. A series of optically active poly(amide- imide)s with moderate yield and inherent viscosity of 0.14 – 0.22 dL/g were obtained. All of the above polymers were fully characterized by IR, elemental analyses, and specific rotation. Some structural characterization and physical properties of this optically active poly(amide-imide)s are reported. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3281–3291, 2004 Key words: polyamides; polyimides; microwave irradiation; l-phenylalanine; viscosity INTRODUCTION The energy of microwave radiation is a useful source for the synthesis of organic compounds. For this pur- pose, it is necessary to use a polar media to absorb energy from radiation and translate to the reacting system. This can create a new method for preparing of chemical compounds. 1–5 In the field of polymers, the various types of processing or synthesis, such as crosslinking of bisamides, 6 the synthesis of poly- ethers, 7 polyurethanes, 8 imidization of polyamic ac- ids, 9 and the direct polycondensation of aromatic dia- mines 10 are from the interesting efforts of using of microwave radiation. Recently, we have also used microwave irradiation for the synthesis of organic compounds as well as macromolecules. 11–16 On the other hand, optically active polymers have found interesting applications because of their specific properties. For example these polymers have the abil- ity of molecular recognition, which cause to use them as a stationary phase in chromatographic methods for enantiomeric separations. 17–22 they can also be used as chiral media for asymmetric synthesis and chiral liq- uid crystals in ferroelectric and nonlinear optical de- vices. 23,24 Therefore, the synthesis and application of optically active polymers have been receiving more attention. In this area, recently, we have synthesized optically active polymers by different methods such as modification of polybutadiene with an optically active substituted urazole group, 25 Diels-Alder-Ene reac- tions, 26,27 and the reaction of an optically active mono- mer with several diamines via solution polymeriza- tion. 28 –36 In the last case, we use amino acids as a chiral agent in the backbone of the polymers. Because the amino acids are naturally occurring compounds, synthetic polymers based on amino acids are expected to be nontoxic, biocompatible, and biodegradable. On the other hand, synthetic polymers containing amino acid residues in the main chain, 37– 41 or in the side chain 42 can be used for biomedical applications. In continuation of our previous works, 28 –36 here, we wish to report the synthesis and characterization of new optically active poly(amide-imide)s PAIs contain- ing EPICLON moieties by using a microwave oven *Previous name: Shadpour E. Mallakpour. Correspondence to: S. Mallakpour (MALLAK@CC.IUT. AC.IR). Contract grant sponsors: Research Affairs Division Isfa- han University of Technology (IUT), Isfahan; Center of Ex- cellency in Chemistry Research (IUT). Journal of Applied Polymer Science, Vol. 91, 3281–3291 (2004) © 2004 Wiley Periodicals, Inc.