氧化纤维素的制备及结构和性能的研究

目的：将天然纤维素氧化制得氧化纤维素，并对氧化纤维素的羧基含量、结构和可吸收性能进行研究。方法：用HNO3／H3PO4-NaNO2氧化体系制备氧化纤维素，分别通过酸碱中和滴定法和红外光谱法测定氧化纤维素中羧基含量。采用红外光谱、固相^13C CP／MASNMR和电镜扫描对其结构进行鉴定。选用新西兰实验兔进行氧化纤维素植人试验，考察其生物可降解性能。结果：该氧化体系可选择性氧化天然纤维素的C6位伯羟基，制得的羧化度为18．46％的氧化纤维素90秒内可止血，动物体内9天可降解、吸收。结论：通过该氧化体系制备的6-羧基纤维素具有良好的止血和吸收性能，可用于外科手术。

Preparation of the Oxidized Cellulose and the Related Study on Its Structure and Performance

Objective： To prepare oxidized cellulose from the natural cellulose and to evaluate its quality through structure, carboxyl content and bioabsorbability. Methods： The oxidized cellulose was prepared in HNO3/H3PO4-NaNO2 oxidation system. The carboxyl content of oxidized cellulose was determined by acid-base titration and FT-IR spectroscopy. The structure of oxidized cellulose was verified by FT-IR spectroscopy, selid-state ^13C CP/MAS NMR and electron microscope scanning. The absorbability and the hemostatic properties were determined by implantation of the oxidized cellulose in New Zealand white rabbits. Results： The C6 primary hydroxyl groups of the natural cellulose were selectively oxidized to carboxyl groups and the C2, C3 secondary hydroxyl groups had no sign to be oxidized. The oxidized cellulose of 18.46% in carboxyl content can stop bleeding in 90 seconds, and it can be biodegrated in 9 days. Conclusion： The oxidized cellulose prepared from the mixture of HNO3/H3PO4-NaNO2, has good hemostasis and absorbability, and can be used in surgical operation.