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32. Synthesis, characterization, and degradation of a novel L-tyrosine-derived polycarbonate for potential biomaterial applications

Author

Cheng Jia Chang, Zheng Yuan Suo, Huang Xia, and Gao Ji Qiang

Subjects
chemistry.chemical_classification, Thermogravimetric analysis, Materials science, Dipeptide, Polymers and Plastics, General Chemistry, Polymer, Biodegradable polymer, Surfaces, Coatings and Films, Gel permeation chromatography, chemistry.chemical_compound, Differential scanning calorimetry, chemistry, Chemical engineering, visual_art, Polymer chemistry, Materials Chemistry, visual_art.visual_art_medium, Polycarbonate, Glycolic acid
Abstract

A novel class of pseudo-poly(amino acid)s was synthesized with a cyclic dipeptide as new diphenole. Nonpeptide bonds alternating with a peptide bond structure were introduced into the backbone of the pseudo-poly(amino acid)s. The cyclic dipeptide in this study was obtained from natural L-tyrosine. L-Tyrosine is a major nutrient amino acid with a phenolic hydroxyl group, so a polycarbonate derived from the cyclic dipeptide should possess more optimum mechanical properties, bioactivity, and biocompatibility. The hydrolytic specimen of the resulting polycarbonate was prepared by a modified solvent evaporation process. Under strongly alkaline conditions, degradation testing was performed. The tyrosine-derived polycarbonate possessed a low glass-transition temperature value and a high thermal decomposition temperature value, which formed a broad mean thermal processing range. The most important results of our study were the effects of the polycarbonate degradation on the local pH values, which were smaller than those of other biodegradable polymers [e.g., poly(lactic acid), poly(glycolic acid), and poly(lactic glycolic acid)]. The synthesized polymer and cyclic dipeptide were characterized with Fourier transform infrared, 13C-NMR, and 1H-NMR spectroscopy to determine their chemical structures; by differential scanning calorimetry and thermogravimetric analysis to determine the thermal properties of the polymer; by gel permeation chromatography to determine the polymer's molecular weight; and by X-ray diffraction to determine the polymer's morphology. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Published
2008

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