A new diamine monomer, 1,4-bis(4-aminophenoxycarbonyl)-2-(4-trifluoromethylphenoxy)benzene containing the trifluoromethyl and ester groups, was prepared from 2-(4-trifluoromethylphenoxy)terephthalyol chloride and 4-nitrophenol in two steps. Then, a series of novel aromatic poly(ester amide)s containing pendant trifluoromethylphenoxy groups with inherent viscosities of 0.511.14 dL/g have been prepared by low-temperature solution polycondensation from this diamine with various aromatic diacid chlorides. All the poly(ester amide)s are amorphous and readily soluble in many organic solvents such as N,N-dimethylacetamide (DMAC) and dimethyl sulfoxide. Tough and flexible polymer films cast from DMAc solutions have tensile strengths of 89114 MPa, elongations at break of 5.88.8%, and initial moduli of 2.23.2 GPa. These poly(ester amide)s show glass transition temperatures between 166 and 256 degrees C, 10% weight loss temperatures ranging from 395 to 445 degrees C, and char yields higher of 46-56% at 800 degrees C in nitrogen, and also exhibit low dielectric constants ranging from 3.31 to 3.52 (1 MHz), and high transparency with an ultravioletvisible absorption cut-off wavelength in the 362-380 nm range. (C) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012