Synthesis And Characterization Of Polyglycolicacid

Polyglycolide acid is a kind of simple polyester with excellent biodegradability and biocompatibility. Carbon dioxide and water, as its ultimate degraded products, can be excreted from the body via metabolism. This important macromolecule material, hence, is widely applied in such fields as inside fixing for human body or animal bone fracture, repairing of bone defection and damage, sewing up of human body or the animal blood vessel, muscle and the other organizations. This thesis illustrates polymerization of PGA by using Chloroacetic acid contract-synthesize polymerization with solvent.There are two means available for the preparation of PGA, namely, contract-synthesis polymerization and ring-opening polymerization. The former is a simple method that polymerizes PGA through direct heating of hydroxyl acetic acid with the advantages of short procedure, simple operation, less involved equipment, and less reagent consumption. Nevertheless, the molecular weight of the PGA has use value generally within the scope of 10000 or a little bit more and the degree of polymerization is very low, which enable it far from perfect to satisfy the practical requirements for sewing in surgical operations and transplantation. In contrast, the means of ring-opening polymerization can synthesize the PGA with high molecular weight through Ethlactide. However, the Ethlactide is required with high purity, and the synthesis process is very complex with low rate of products and high cost.This thesis synthesizes PGA by using Chloroacetic acid and Triethylamine with equal Moore concentrations to contract-synthesize polymerization with solvent.The author observes and investigates the impact of different ratio of raw material, time of reaction, choices of solvents, temperature of reaction and the choices of detergent on the production rate, from which the optimum technological conditions for polymerization of PGA through chloroacetic acid solvent are accordingly specified. Additionally, the performance of polymer is characterized from the aspects of FT-IR-Raman, XRD and the DSC and TGA. And the degradation of PGA in different buffer liquor is observed and further evaluated.The optimum technological parameters suggested by the experiment are as follows: the ratio of raw material is 1:1, Acetone is the ideal solvent in the condition of condensation and circumfluence, the temperature is 65 °C, the heating and circumfluence time is 4 hours and is washed. The polymer is heated at the state of meltdown to be polymerized again and washed two or three times with the absolute of Ethyl alcohol.