Synthesis and characterization of optically active polyamides based on 2-(1,3-isoindolinedione-2-yl)glutaric acid by direct polycondensation

Five new optically active polyamides(PAs)6a-6e were prepared by direct polycondensation reaction of 2-(1,3-isoindolinedione-2-y1)-glutaric acid 4 as a new chiral diacid with various aromatic diamines 5a-5e in a medium consisting of triphenyl phosphite(TPP),calcium chloride,pyridine(Py)and N-methyl-2-pyrrolidone(NMP).The polycondensation reaction produced a series of polyamids 6a-6e in quantitative yields with inherent viscosities of 0.26-0.39 dL/g.The resulting polymers were fully characterized by means of 1H-NMR,FT-IR spectroscopy,elemental analysis,inherent viscosity and specific rotation.Thermal properties of these polymers were investigated using thermal gravimetric analysis(TGA)and differential thermal gravimetry(DTG).Phthalimide rings as a bulky pendent group in the polymer chains disturb the interchain and intrachain interactions and make these PAS readily soluble in polar,aprotic solvents such as N,N-dimethyl acetamide(DMAc),N,N-dimethyl formamide(DMF),dimethyl sulfoxide(DMSO),N-methyl-2-pyrrolidone(NMP)and sulfuric acid.