Incorporation of a Novel Heat Stability Enhancing Fluorinated Diol into Nanostructure Poly(Ester-Imide)s via the Low Temperature Solution Polycondensation

Abstract

4,4′-hexafluoroisopropylidene-2,2-bis-(phthalic anhydride) has been reacted with 2 moles of L-tyrosine methyl ester in the refluxing N,N′-dimethylformamide to obtain 4,4′-(hexafluoroisopropylidene)-N,N′-bis-(phthaloyl-L-tyrosine methyl ester) as a novel fluorinated diol for the first time. A series of new nanostructure poly(ester-imide)s (PEIs) was synthesized by the polycondensation reaction of several amino acid based-diacid chloride with the synthesized diol. The PEIs were obtained in good yields and moderate inherent viscosity. On the basis of thermogravimetric analysis data, such polymers are thermally stable and can be classified as self-extinguishing macromolecules. Morphology study of resulting PEIs showed the nanostructure phenomena of these polymers by the FE-SEM technique.

Keywords:

• Amino acids
• Fluorinated diol
• Heat stable macromolecules
• Nanostructure poly(ester-imide)s
• Polycondensation

ACKNOWLEDGMENTS

We wish to express our gratitude to the Research Affairs Division Isfahan University of Technology (IUT), Isfahan, for partial financial support. Further financial support from Iran nanotechnology Initiative Council (INIC), National Elite Foundation (NEF) and Center of Excellence in Sensors and Green Chemistry Research (IUT) are gratefully acknowledged.

Notes

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

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

^b PY = Pale yellow.

^a Temperature at which 5% weight loss was recorded by TGA at heating rate of 20°C/min under nitrogen atmosphere.

^b Temperature at which 10% weight loss was recorded by TGA at heating rate of 20°C/min under nitrogen atmosphere.

^c Weight percentage of material left undecomposed after TGA analysis at a temperature of 800°C under nitrogen atmosphere.

^d Limiting oxygen index (LOI) evaluating char yield at 800°C.