Synthesis of Poly(galactaramides) from Alkylene- and Substituted Alkylenediammonium Galactarates

Abstract

Polyhydroxypolyamides (PHPAs) represent a class of synthetic polyamides derived from aldaric acid and diamine monomer units. This paper describes the synthesis of some poly(galactaramides), a class of polyhydroxypolyamides, that employs alkylene and substituted alkylenediammonium galactarate salts, with 1:1 molar equivalency of the diacid and diamine monomer components, as precursors for the polyamides. The salts were treated with acid/alcohol and then base in order to initiate the polymerization in methanol. The polyamides, labeled as prepolyamides, precipitated from solution and were then subjected to a second polymerization (postpolymerization) in a different solvent to produce a generally larger polyamide, labeled as a postpolyamide.

Keywords:

• Polyamides
• Structure-property relationship
• Polyhydroxypolyamides
• Poly(galactaramides)

ACKNOWLEDGMENTS

Significant financial support for this research was from the U.S. Department of Agriculture (USDA-CREES Grant Nos. 2004-364463, 2005-34463-11561, and 2006-34463-16886) and is gratefully acknowledged.

Notes

^a In D₂O referenced to t-BuOH at 1.203 ppm.

^b Insoluble in any suitable NMR solvent.

^a In DMSO-d 6 referenced to TMS at 0.00 ppm.

^a In TFA-d referenced to residual TFA at 11.50 ppm unless otherwise indicated.

^b In D₂O referenced to t-BuOH at 1.203 ppm.

^c Very broad multiplet.

^d Split in D₂O but becomes a singlet on addition of base.

^e In DMSO-d 6 referenced to TMS at 0.00 ppm.

^a Determined by NMR in TFA-d.

^b Determined by NMR in D₂O.

^c Too great to be determined by this method.

^d Determined by NMR in DMSO-d 6.