Two series of poly(imide-ester)s (PIEs) and poly(ether-imide-ester)s (PEIEs)

having benzoxazole or benzothiazole pendent groups

were conveniently prepared by the diphenylchlorophosphate-activated direct polyesterification of two bis(imide-carboxylic acid)s (

1

)

such as 2-[3

5-bis(N-trimellitimidoyl)phenyl]benzoxazole (1

O

) and 2-[3

5-bis(Ntrimellitimidoyl) phenyl]benzothiazole (1

S

) and two bis(imide-ether-carboxylic acid)s (2)

such as 2-[3

5-bis(4-trimellitimidophenoxy)-phenyl]benzoxazole (2

O

)

and 2-[3

5-bis(4-trimellitimidophenoxy)-phenyl]benzothiazole (2

S

) with various aromatic dihydroxy compounds in the presence of pyridine and lithium chloride. The structures

solubilities and thermal properties of obtained polymers were investigated in detail. All of the resulting polymers were characterized by FTIR and

1

H-NMR spectroscopy and elemental analysis. All of the resulting polymers exhibited excellent solubility in common organic solvents

such as pyridine

tetrahydrofuran and

m

-cresol

as well as in polar organic solvents

such as

N

-methyl-2-pyrrolidone

N

N

-dimethylacetamide

N

N

-dimethylformamide and dimethyl sulfoxide. The modified polymers were obtained in quantitative yields with inherent viscosities between 0.47 and 0.67 dl⋅g

−1

. Experimental results indicated that all the polymers had glass transition temperature between 198 ℃ and 262 ℃

the decomposition temperature at 10% weight loss between 398 ℃ and 531 ℃ under nitrogen.