Drugs Accessories Polylactic Acid - Glycolic Acid 75/25 (plga75/25) Synthesis, Quality And Dynamics Study

Poly(lactic acid) is one of the polyester, which can be broken into carbon CO₂ and H₂O in the effect of O₂ and H₂O, and processes performances of bio-compatibility, bio-degradability and avirulence, so it was used widely in the device and medical fields. It processes properties of high tensile strength and compression modulus, but lacks of rigidity, tenacity, flexibility; at the same time PLA is short of hydrophile capability and a reactive function group in it's chemical structure. There was a great of work made to improve it's hydrophile capability lately especially in study of poly(lactide-co-glycolide). At present, people are focusing on the synthesis of PLGA by hydroxy fatty acid. Stannous octanoate was usually as katalyst, which was mephitical for body. However, PLGA must be of low nocuity or innocuity in some special applications of medicament. In this article, high-pure lactic acid and ethanol acid were used to synthesized PLGA by direct condensation polymerization, and zinc octanoate of low nocuity was used as katalyst, instead of stannous octanoate to synthesize PLGA by the way of opening ring.In this article, we focused on the synthesis of poly(lactide-co-glycolide) and it's quality analysis. Lactide was prepared by the method of decompression distillation and it's purity is also analyzed in this paper. The direct condensation polymerization of lactic acid and ethanol acid was studied without catalyzer or with strongly acidic cationic exchange resin as catalyzer. It was indicated that the maximal molecular weight of the polymer can respectively reach to 4976 with 37% output in the conditions of 165℃,0.01MPa,16h and 5579 whit 38.4% output in the conditions of 165℃, 0.01MPa, 16h and 0.1 %( katalyst).Different molecular weight PLGA(75/25) was synthesized with zinc octanoate or stannous octanoate as catalyst and blocked with H₂O or dodecyl alcohol. The affects of two catalyzers for synthesis were also discussed to make sure whether zinc octanoate can be used to replace stannous octanoate. At the same time, H₂O was compared with dodecyl alcohol to investigate their affects of polymer molecular weight. It was indicated that the maximal...