| Summary: | 碩士 === 國立陽明大學 === 醫學工程研究所 === 89 === Poly(lactides) materials have been applied widely in the field of biomedical. For the purpose of degradation affected by the polymer synthesis and forming properties. In this research, we synthesized and produced three different crystallinities of poly(lactides), made them become homogeneous films with non pores, put them into the buffer solutions of different pH values and studied the influence of poly(lactides) degradation properties between different crystallinities under unequal acidities. After synthesis and purification procedure of experiment, we can obtain L-lactide、 DL-lactide、 poly(L-lactides) and poly(DL-lactides). All with them were exact structure and high purity. On the condition of forming, poly(lactides) dissolves in CH2Cl2 at the concentration of 13wt%, forming films and evaporated the solvent under 5℃, the best homogeneous films without pores was produced. If setting them into the buffer solutions of different pH values for degradation and analyze the variation of film weight, thermal properties alone with molecular weight, it is clear that under pH=3.0~12.0, the degradation rate in neutral environment was slower than other pH values. However, the degradation rate in alkaline environment was the fastest. Three kinds of poly(lactides) films under pH=12.0, for instance, they were almost complete degraded in 10 days. In addition, the swelling of poly(lactides) films was negligible. The degree of degradation rate and dimension variation of films after degradation was: LPLAcry films<LPLAam films<DLPLA films.
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