Synthesis And Biodegradability Differential Study Of Novel Polyamide-imides Based On The Amino Acids

With excellent performance,after discarding reusable,disposable,biodegradable polymer materials development has been the target polymer materials,in particular to develop a controllable degradation rate of the polymer material is a hot research question.Polyamide-imides are a high performance thermoplastic resin,having good mechanical properties,high temperature performance,adhesion properties.The introduction of natural amino acids make the use of the polyamide-imides may have better performance,such that optically active,biocompatibility and biodegradability,and so on,may bring new green revolution into a polymer.Therefore,the study of factors affecting the biodegradation of this kind of polymers is particularly important.This paper mainly studied the influence of the natural non-chiral amino acid for the polyamide-imide degradation performance and the participation of the natural chiral amino acid for the random copolymerzation the polyamide-imides degradation performance impact.This paper selects L-alanine,L-phenylalanine,L-leucine also selected glycine,4-aminobutyric acid and 6-aminocaproic acid,with the help of their synthesized six kinds of aromatic polyimide acid monomer.The novel polyamide-imides were synthesized by direct polycondensation reaction of acid monomer with diaminodiphenyl ether by using the triphenyl phosphate(TPP),pyridine(Py)as the acylating agent,CaCl2 as catalyst and N-methyl pyrrolidone(NMP)as the solvent.Acid monomer and polymer were characterized by 1H-NMR,FT-IR,optical rotation,DSC,GPC,TGA,elemental analysis,and so on.Solubility experiments confirmed that the solubility of the polymer was obviously improved,due to the introduction of chiral amino acid.The polymer has good thermal stability and high glass transition temperature(Tg).Biodegradation studies on seven homopolymerized and copolymerized PAI's show that the PAI's based on natural achiral amino acid-glycine has a certain degree of degradation,while the rate of biodegradation of the copolymerized PAI's after the incorporation of non-natural achiral amino acid has significantly decreased,the rate of biodegradation of the copolymerized PAI's after incorporation of natural chiral amino acid has obviously increased.The results of the semi-quantitative studies show that we can control the rate of biodegradation by controlling the types and proportions of the amino acids constituting the structure of PAI's,which provides development possibility of polymer materials with different rate of degradation.