Synthesis, Characterization, and Thermal Properties of New Organosoluble Poly(ester-imide)s Containing Ether Group

A new series of aromatic poly(ester-imide)s (PEIs) 8a-f with 1,3-bis[4-aminophenoxy]propane moieties were prepared from the newly synthesized diacid monomer 6 with various aromatic diols 7a-f. The resulting polymers were fully characterized by Fourier transform infrared spectroscopy (FTIR) and H-1 nuclear magnetic resonance spectroscopy (H-1 NMR), elemental analysis, inherent viscosity, solubility tests, thermogravimetric analysis (TGA), and derivative of thermogravimetric (DTG) analysis. The PEIs had inherent viscosity ranging from 0.18 to 0.90 dL/g and were soluble in common organic solvents, such as N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), and dimethyl sulfoxide (DMSO). They exhibited useful thermal properties associated with relatively moderate T(g)s (210-220 degrees C), 10% weight loss temperatures in excess of 380 degrees C, and char yields at 800 degrees C in N-2 of up to 29%. Dicarboxylic acid 6 was synthesized from the reaction of 1,3-bis[3-aminophenoxy]propane 4 with trimellitic anhydride 5 in a solution of glacial acetic acid/pyridine (Py) at the refluxing temperature. 1,3-Bis[4-nitrophenoxy]propane 3 was prepared by a reaction of 4-nitrophenol 1 with 1,3-dibromo propane 2 in a DMF solution. Dinitro 3 was reduced to diamine 4 using 10% Pd-C, ethanol and hydrazine monohydrate.