Syntheses and properties of new poly(amide-imide)s based on 1,4-bis(4-aminophenoxy)naphthalene and various diimide-diacids

A series of new alternative poly(amide-imide)s (PAIs, IIIa-j) was synthesiz ed by the direct polycondensation of 1,4-bis(4-aminophenoxy)naphthalene (1, 4-BAPON) with various aromatic diimide-diacids. These polymers were obtaine d in quantitative yields with inherent viscosities of 0.71-1.03 dL/g. Excep t for IIIa, most of the polymers were soluble in aprotic polar solvents suc h as NMP, DMAc, DMF, and DMSO and could be solution-cast into transparent, flexible, and tough films. The glass transition temperatures of these PAIs were in the range of 235-280 degrees C. Thermogravimetric analyses establis hed that these polymers were fairly stable up to 450 degrees C, and 10% wei ght; loss temperatures were recorded in the range of 520-569 degrees C unde r nitrogen and 506-566 degrees C under an air atmosphere, Compared with the PAIs with the 1,4-bis(4-aminophenoxy)benzene structure (series TV), the so lubility of series III was better than that of series TV. Series III also e xhibited lower crystallinity and better processability than those of series TV. (C) 2000 John Wiley & Sons, Inc.