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具有温度敏感的生物水凝胶因可根据温度变化发生相变而受到人们重视。采用直接熔融聚合法,先以外消旋乳酸(D,L-LA)和L-亮氨酸(Leu)为原料,辛酸亚锡为催化剂,合成了聚乳酸-聚亮氨酸;再以一定比例将上述两组分共聚物与一定分子量的聚乙二醇(PEG)混合,在辛酸亚锡为催化剂的情况下熔融聚合制备聚乳酸-聚亮氨酸-聚乙二醇三组分嵌段共聚物。采用傅里叶红外光谱(FTIR)、核磁共振波谱仪(1 H-NMR)和凝胶渗透色谱仪(GPC)对两组分和三组分共聚物进行了系统表征,所得三组分共聚物的一定浓度的水溶液在20～35℃时具有溶胶-凝胶转变特性,能够满足该生物友好材料在药物缓释领域中的应用。
Temperature-sensitive bio-hydrogels have drawn great attention due to the phase transitions that can occur due to temperature changes. Polylactic acid-poly-leucine was synthesized by direct melt polymerization using stannous octoate as raw material and racemic lactic acid (D, L-LA) and L-leucine as raw materials. The above two-component copolymer is mixed with polyethylene glycol (PEG) of a certain molecular weight and is melt polymerized in the presence of stannous octoate as a catalyst to prepare a polylactic acid-poly-leucine-polyethylene glycol three-component block copolymer Things. The two-component and three-component copolymers were systematically characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (1 H-NMR) and gel permeation chromatography (GPC) Aqueous solution with a certain concentration has a sol-gel transition characteristic at 20-35 DEG C and can meet the application of the bio-friendly material in the field of drug sustained release.