Novel Thermally Stable Poly(amide-imide)s Containing Dibenzalacetone Moiety in the Main Chain: Synthesis and Characterization

A new-type of dicarboxylic acid 6 was synthesized from a reaction of 1,5-bis(4-aminophenyl) penta-1,4-dien-3-one 4 with trimellitic anhydride 5 in a glacial acetic acid/pyridine (Py) solution at refluxing temperature. Eight novel thermally stable poly(amide-imide)s (PAIs) 8a-h with good inherent viscosities were synthesized from a direct polycondensation reaction of N,N'-(1,5-bis(4-aminophenyl) penta-1,4-dien-3-one) bistrimellitimide 6 with several aromatic diamines 7a-h through direct polycondensation using the N-methyl-2-pyrrolidone (NMP)/pyridine (py)/triphenyl phosphite (TPP) system as a condensation agent. All the above polymers were fully characterized by 1 H NMR, FTIR, elemental analysis, inherent viscosity, solubility tests, UV-vis spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and the derivative of thermaogravimetric (DTG). The resulting poly(amide-imide) s (PAIs) 8a-h showed good inherent viscosities (0.41-0.70 dL/g), good thermal stability and solubility.