Preparation and characterization of new thermally stable and optically active polyesters by direct polycondensation reaction promoted by Vilsmeier adduct

Abstract

AbstractHighly soluble and optically active aromatic polyesters (PE)s containing phthalimide and flexible chiral groups were prepared with moderate molecular weights by step-growth polymerization of diacid monomer containing pendant 4- [(2L)-phthalimidylpropanoylamino)benzoyl group with several aromatic diols, in a system of tosyl chloride, pyridine (Py) and N,N-dimethylformamide (DMF) to give a series of new optically active PEs with good yield and moderate inherent viscosity ranging from 0.28 to 0.48 dL/g. The aim of this work was to obtain novel optically active PEs that was more soluble in common organic solvents while maintaining the high thermal stability. All polymers derived from such a diacid and aromatic diols were highly organosoluble in solvents like N-methyl-2-pyrrolidinone, N,Ndimethylacetamide, DMF, Py, dimethyl sulfoxide. Thermogravimetric analysis data showed that these PEs are thermally stable, with 10% weight loss being recorded above 400 °C and showed good thermal stability associated with high glasstransition temperatures above 200 °C as measured by differential scanning calorimetry. All of the above polymers were characterized by FT-IR and specific rotation techniques and some of them were also characterized by 1H-NMR and elemental analyses methods.