Synthesis and characterization of new optically active poly(amide-imide)s containing epiclon and L-methionine moieties in the main chain

Epiclon [3a,4,5,7a-tetrahydro-7-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-1,3-isobenzofurandione] (1) was reacted with L-methionine (2) in acetic acid and the resulting imide-acid 3 was obtained in high yield. The diacid chloride 4 was prepared from diacid derivative 3 by reaction with thionyl chloride. Thermostable poly(amide-imide)s containing epiclon structure were synthesized by reacting of diacid chloride 4 with various aromatic diamines. Polymerization reaction was performed by two conventional methods: low temperature solution polycondensation and short period reflux conditions. In order to compare conventional solution polycondensation reaction methods with microwave-assisted polycondensation, the reactions were also carried out under microwave conditions with a small amount of o-cresol that acts as a primary microwave absorber. The reaction mixture was irradiated for 6 min with 100% radiation power. Several new optically active poly(amideimide)s with inherent viscosity ranging from 0.15 to 0.36 dl/g were obtained with high yield. All of the above polymers were fully characterized by H-1-NMR, FT-IR, elemental analyses and specific rotation techniques. Some structural characterizations and physical properties of these new optically active poly(amide-imide)s are reported. Copyright (c) 2005 John Wiley & Sons, Ltd.