壳聚糖-聚羟基丁酸酯接枝共聚物的制备与表征

背景：壳聚糖／聚羟基丁酸酯共混或共聚材料的研究因壳聚糖和聚羟基丁酸酯特殊的生物来源而倍受关注，但尚无合适的方法对二者进行有效的聚合。 目的：在均相条件下，以温和的引发剂引发获得壳聚糖／聚羟基丁酸酯接枝共聚物。 设计、时间及地点：单一样本试验，于2007—08／10在西安建筑科技大学化学实验研究中心完成。 材料：壳聚糖（DD=100％，Mη=123000，为日本Kyoto公司产品。聚-3-羟基丁酸酯由购白Aldrich chemicals的聚羟基丁酸酯树脂在醋酸中降解精制得到，Mr10000。 方法：以过氧化二苯甲酰为引发剂，在醋酸-二甲基亚砜复合体系中进行聚-3-羟基丁酸酯与壳聚糖的接枝反应。反应温度为85℃，在氮气保护下反应5h。红外分析、核磁共振分析和元素分析证实了接枝反应的发生及接枝产物的化学结构。用广角X线衍射和热重／差热分析分别表征了接枝产物的晶体形态和热稳定性。 主要观察指标：接枝产物的化学结构、晶体形态、热稳定性。 结果：产物经红外分析、核磁共振及元素分析证实了接枝反应的发生，广角X射线衍射和热重分析表明，接枝产物的结晶状态不同于壳聚糖和聚羟基丁酸酯，且具有一定的热稳定性。 结论：以过氧化二苯甲酰为引发剂，可以制备出性质稳定的壳聚糖／聚羟基丁酸酯接枝共聚物。

Preparation and characterization of chitosan-g-poly (3-hydroxybutyrate) copolymer

BACKGROUND: Chitosan/poly (3-hydroxybutyrate) (PHB) copolymer has been paid close attention for special biological source of Chitosan and PHB. However, there has been no proper method for them to polymerize effectively.OBJECTIVE: To prepare chitosan/PHB graft copolymer in a homogeneous medium, using a gentle initiator.DESIGN, TIME and SETTING: This study, a single-sample experiment, was performed at the Research Center of Chemistry, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province, China from August 2007 to October 2007.MATERIALS: Chitosan: DD=100%, Mη=123000, Kyoto, Japan. PHB was purchased from Aldrich chemicals and the molecular weight was 10000.METHODS: Chitosan was grafted with poly (3-hydroxybutyrate) (PHB) in acetic acid/dimethyl sulfoxide system, and benzoyl peroxide (BPO) was used as initiator. The reaction temperature was 85℃ and the reaction continued for 5 hours with nitrogen protection. Grafting reaction and the chemical structure of the copolymer were confirmed by infrared analysis, NMR and elemental analysis. The crystal form and thermal stability of copolymer were characterized with wide-angel X-ray diffraction (WAXD) and thermogravimetric/differential thermal analysis balance, respectively.MAIN OUTCOME MEASURES: The chemical structure of copolymer, crystal form as well as thermal stability.RESULTS: Grafting reaction was confirmed by infrared analysis, NMR and elemental analysis. Wide angle X-ray diffraction and thermogravimetric analysis indicated that graft copolymer was different from chitosan and PHB in crystalline morphology, and had a good thermal stability.CONCLUSION: Using BPO as initiator, chitosan/PHB grafting copolymer is prepared and it has a steady property.