pH and reduction sensitive bio-based polyamides derived from renewable dicarboxylic acid monomers and cystine amino acid

ABSTRACT

New reduction biodegradable and pH-sensitive linear nonpeptidic polyamides were synthesized by interfacial polycondensation of diamines and cystine amino acid with dicarbonyl dichlorides derived from renewable dicarboxylic acids. The polymer degradability by glutathione is enhanced by the introduction of disulfide linkages, and the response to pH change is enhanced by introducing pendant carboxylic acid functions. The results of pH sensitivity tests indicated that protonation–deprotonation of the carboxylic acid group at about pH of 4.1 with cation exchange capacity 4.5 meq g⁻¹ and the disulfide bonds in polyamides were effectively cleaved.

KEYWORDS:

• Disulfide bond
• interfacial polymerization
• nonpeptidic polyamides
• pH sensitive
• reduction biodegradation

Acknowledgments

The authors gratefully acknowledge the University of Jordan for providing the facilities and chemicals. The authors thank Ms. Fatima Mustafa and Ms. Rula Hassouneh for NMR measurements and Ms. Ruba Zalloum and Mrs. Abeer Malhis for FTIR and thermal analyses measurements.