Synthesis And Biodegradation Studies Of Optically Active Poly(Amide-imide)s Based On Amino Acid

Optically active poly(amide-imide)s based on amino acids not only has excellent properties of polyamide and polyimide, while has optically active, but also has potential biocompatibility and biodegradability resulted from insertion of amino acids moieties in to the polymer backbones. The development of polymer materials has made tremendous contributions for the progress in nowadays society, however, polymer material waste has brought negative impact to the environmental pollution that can not be ignored, the worsening of "white pollution" that need urgent solutions. It is imperative that make the polymer materials green. Research and development of biodegradable and environmentally friendly materials have great significance.The biodegradability study of poly(amide-imide)s not only conforms to the concept of green chemistry, but also has great economic and ecological benefits.In this paper, firstly, optically active acid monomers were prepared by the condensation reaction of the L and D-amino acids as chiral source and pyromellitic dianhydride under conditions in glacial acetic acid as the solvent. The structure and properties of the monomers were characterized by IR and 1H-NMR, elemental analysis, optical rotation and melting point. Then, the optically active acid monomers reacted with diaminodiphenyl ether by di-imines carbonic acid method to prepared optically active poly(amide-imide)s, which has high yield and good purity. The structure and properties of the the resulting polymers were characterized, IR and 1H-NMR characterized its structure, automatic polarimeter measured its optical rotation, viscosity method measured its molecular weight, differential scanning calorimetry and thermal gravimetric analyzer characterized its thermal performance, and its solubility was discussed. Finally, The biodegradablility of optically active poly(amide-imide)s were studied with soil and phosphate buffer solution as degradation environment. Its biodegradation mechanism was discussed, and the test experiments were made to research the environmental soundness of degradation products. The results shown that the optically active poly(amide-imide)s having good biodegradability, which is harmless to the environment. Its biodegradation mechanism is hydrolysis of amino acid derivative amides and broken of C-N bonds.