Synthesis and characterization of new optically active poly(amide-imide)s based on N-trimellitimido-L-amino acid and trimethylene units
Six new optically active poly(amide-imide)s (8a-f) were synthesized through the direct polycondensation reaction of 1,3-bis(4-aminophenoxy) propane (4) with six different derivatives of N-trimellitimido-L-amino acid (7a-f) in a medium consisting of N-methyl-2-pyrrolidone, triphenyl phosphite, calcium chloride and pyridine. The polycondensation reaction produced a series of novel poly(amide-imide)s (8a-f) containing trimethylene moiety in the main chain in high yield with inherent viscosities between 0.45 and 0.80 dL/g. The resulting polymers were fully characterized by means of FTIR spectroscopy, elemental analyses, inherent viscosity, and solubility tests. Thermal properties of these polymers were investigated by thermal gravimetric analysis (TGA) and differential thermal gravimetric (DTG). All of the polymers were readily soluble in a variety of organic solvents such as N,N'-dimethyl formamide (DMF), N,N'-dimethyl acetamide (DMAc), dimethyl sulfoxide (DMSO) and N-methyl-2-pyrrolidone (NMP) at room temperature. They had 10% weight loss at a temperature above 360 °C and left 42.0–55.6% residue even at 600 °C in nitrogen.
KEY WORDS: High performance polymers, Poly(amide-imide)s, Direct polycondensation, Trimethylene moiety
Bull. Chem. Soc. Ethiop. 2011, 25(1), 97-102.