SYNTHESIS AND CHARACTERIZATION OF NEW POLY(AMIDE-IMIDE)S FROM 4-BIS(4-TRIMELLITIMIDOPHENOXY)-2-TERT-BUTYLBENZENE WITH VARIOUS DIAMINES

New poly(amide-imide)s were prepared from a diimide-dicarboxylic acid, 4-bis(4-trimellitimidophenoxy)-2-tert-butylbenzene (BTTB), with vario us diamines by the direct polycondensation in N-methyl-2-pyrrolidinone (NMP) using triphenyl phosphite and pyridine as condensing agents. Th e new diimide-dicarboxylic acid BTTB containing an ether linkage and t ert-butyl substituent was synthesized by the condensation reaction of 1,4-bis(4-aminophenoxy)-2-tert-butylbenzene with trimellitic anhydride . All the polymers were obtained in quantitative yields with inherent viscosities of 0.62-1.06 dL g(-1). The polymers were amorphous, and mo st of them were readily soluble in aprotic polar solvents such as NMP, N,N-dimethylacetamide (DMAc), and N,N-dimethylformamide (DMF), as wel l as in less polar solvents such as dimethyl sulfoxide (DMSO), m-creso l, pyridine, and gamma-butyrolactone, and also even in tetrahydrofuran . The glass transition temperatures of the polymers were determined by DSC method, and they were in the range of 238-279 degrees C. These po lymers were stable up to 408-449 degrees C in air and 451-483 degrees C in nitrogen and lose 10% weight in the range of 479-525 degrees C in air and 480-528 degrees C in nitrogen atmosphere. The polymer films h ad a tensile strength range of 71-115 MPa, an elongation at break rang e of 4-14%, and a tensile modulus range of 2.3-3.1 GPa. (C) 1998 John Wiley & Sons, Inc.