Synthesis and characterization of new poly(amide-imide)s based on [N,N′-(4,4′-carbonyldiphtaloyl)-bis-L-amino diacid]s and dibenzalacetone moieties in the main chain

Abstract

Six dicarboxylic acids 3a–f were synthesized by the reaction of 3,3′,4,4′-benzophenonetetracarboxylic dianhydride 1 with L-aminoacids 2a–f in a solution of glacial acetic acid/pyridine (Py) at refluxing temperature. Then six new poly(amide-imide)s PAIs were synthesized by direct polycondensation reaction of [N,N′-(4,4′-carbonyldiphtaloyl)-bis-L-amino diacid]s with 2,5-bis(4-aminobenzilidene)cyclopentanone. Due to the presence of dibenzalacetone moiety in the polymer chain, the PAIs have photosensitive properties. Also these PAIs are optically active and soluble in various organic solvents. These resulting new polymers can be used in column chromatography for the separation of enantiomeric mixtures. The resulted polymers were fully characterized by means of FTIR, ¹H NMR spectroscopy, elemental analyses, inherent viscosity, solubility tests, UV–vis spectroscopy, thermogravimetric analysis, and derivative of thermogravimetric.

Keywords:

• polymers
• thermal properties
• glass transition
• optically active polymer

Notes

aMeasured at a concentration of 0.5 g /dL in DMF at 25 °C.

aMeasured at a concentration of 0.5 g /dL in DMF at 25 °C.

^aTemperature at which 5% or 10% weight loss was recorded by TGA at a heating rate of 10 °C/min under N₂.

^bWeight percentage of material left after TGA analysis at a maximum temperature of 800 °C under N₂.

^cLimiting Oxygen Index.