Synthesis, characterization and properties of novel polyamides derived from 4 4MODIFIER LETTER PRIME bis(4-carboxy methylene) biphenyl and various diamines

Novel aromatic aliphatic diacid monomer, 4 4MODIFIER LETTER PRIME bis(4-carboxy methylene) biphenyl was synthesized via friedel craft acylation with acetic anhydride followed by willgerodot reaction and used in the preparation of polyamides by direct polycondensation using the Yamazaki phosphorylation reaction with commercial aromatic diamines. These polyamides were obtained in good yield with moderate-to-high-molecular-weight build up as evidenced by inherent viscosities in the range of 0.52-0.96 dlg-1. The XRD studies showed that all the polyamides were amorphous in nature and these polymers dissolved in polar aprotic solvents such as N-methyl-2-pyrrolidone(NMP),N,N-dimethylsulfoxide(DMSO), N,N-dimethyl formamide (DMF) and N,N-dimethyl acetamide. The resulting polyamides were characterized by inherent viscocity measurements, FT-IR, 1H NMR and 13C NMR spectroscopy, solubility, thermogravimetry, X-ray diffraction studies. These polyamides had glass transition temperatures between 210 degrees C and 261 degrees C, and their temperatures at a 10% weight loss were 620 to 710 degrees C and 497 to 597 degrees C in nitrogen and air atmospheres, respectively, which indicates thermally stable polymers.