The Synthesis And Properties Study Of The Modified Poly Citric Acid Ester

In this paper, the citric acid,1,8-octanediol and1,2-propanediol are used as reactivemonomers to synthesize the1,2-propanediol modified network polyester bioelastomerpoly(1,2-propanediol-co-1,8-octanediol-co-citrate) through the melt polycondensation. Themodified bioelastomers are fabricated to small-caliber artificial blood vessels. Besides, themodified bioelastomers’ structures, properties and drug controlled release carrier propertiesare studied systematically, the artificial blood vessels’ mechanical properties are preliminarilycharacterized too.Firstly, the modified bioelastomers are studied by Fourier transform infraredspectroscopy(FTIR), nuclear magnetic resonance(1H-NMR), thermal gravimetricanalysis(TGA), differential scanning calorimetry(DSC), scanning electron microscope(SEM),sol content test, degree of swelling test, hydrophilicity test, mechanical test and in vitrodegradation test. It is found that the modified bioelastomers are formed by sol, gel and gelbased, besides, they have a better thermal stability. Through the way of increasing thecontents of1,2-propanediol, the modified bioelastomers’ tensile strength is reduced from0.99MPa to0.82MPa and the elongation at break is increased from109%to279%, themodified bioelastomers’ hydrophilicity is enhanced and the degradation period is shorten too.Besides, there is a smaller pH change during the degradation. There are relative lowermodulus for the modified bioelastomers fabricated artificial blood vessels, which indicate thatthey could be the good replacer for the tissue engineering artificial vascular.Secondly, the aspirin is used as a model drug to prepare drug carrying modifiedelastomers by physical blending method, and the drug carrying modified elastomers arestudied. It is found that the drug is loaded onto the surface of the modified bioelastomer easilyand form the crystals. However, the drug did not influence the molecular chain structures andthermal properties of the modified bioelastomers. Drug release tests show that the drugrelease rate is increased when the contents of1,2-propanediol are increased. With the increaseof medicine loading, the drug release rate is increased. With the increase of pH value ofenvironment, the drug release rate is increased.