New optically active poly(amide-imide)s based on N,N′-(pyromellitoyl)-bis-L-amino acid and methylene diphenyl-4,4′-diisocyanate: synthesis and characterization

Abstract

Five new optically active poly(amide-imide)s were synthesized through the direct polycondensation reaction between chiral N,N′-(pyromellitoyl)-bis-L-amino acids and methylene diphenyl-4,4′-diisocyanate in a medium consisting of N-methyl-2-pyrrolidone (NMP) and xylene. The resulted polymers were fully characterized by means of Fourier transform infrared spectroscopy, elemental analyses, and solubility tests. Thermal properties of these polymers were investigated by using thermal gravimetric analysis/SDTA. All of the polymers were soluble at room temperature in polar solvents such as N,N′-dimethyl acetamide, N,N′-dimethyl formamide, dimethyl sulfoxide (DMSO), NMP, sulfuric acid, and para-methyl phenol. Same specific rotations of these polymers in these different solvents were obtained.

Synthesis and biodegradation studies of optically active poly(amide–imide)s based on N,N′-(pyromellitoyl)-bis-l-amino acid

“…6 Among such polymers, amino acid-based poly(amide-imide)s (PAI)s are not only optically active resulted from the insertion of amino acid moieties into the polymer backbones, but are also expected to present biocompatibility and biodegradability similar to polypeptides. [7][8][9][10][11][12][13][14][15] Meanwhile, by incorporating amide and imide functionalities in the polymer main chain, it leads to combined and inherited desirable characteristics like mechanical and thermal properties and better melting processability from both polyamides and polyimides (PIs). [16][17][18][19][20][21][22] Accordingly, they can be employed for biomedical applications like dental materials, temporary artificial skin substrates, metal ion absorbents, biomaterials and polymer carriers for protein conjugates, drug delivery, gene therapy, and tissue engineering.…”