温度/pH敏感型壳聚糖水凝胶的制备及其性能

Preparation and properties of temperature and pH sensitive chitosan hydrogel

以天然可降解高分子壳聚糖为载体,选择温度敏感单体N-异丙基丙烯酰胺以及pH敏感单体2-丙烯酰胺基-2-甲基丙磺酸,以偶氮二异丁腈为引发剂,N,N-亚甲基双丙烯酰胺为交联剂,通过自由基接枝共聚反应制备壳聚糖水凝胶。通过红外(IR)、扫描电镜(SEM)对其结构及形貌进行了表征,并探讨了影响水凝胶溶胀率的因素。结果表明,当单体配比NIPAM∶AMPS为6∶4、引发剂用量为单体总质量4%、交联剂用量为单体总质量的4%、反应温度为45℃形成的水凝胶在水中溶胀率可达95%左右。该水凝胶具有一定的温度和pH敏感性,预计在药物控释、组织工程、抗凝血材料等领域拥有广阔的应用前景。

Chitosan hydrogel was prepared by free radical graft copolymerization using natural biodegradable polymer chitosan as the carrier,temperature sensitive NIPAm and pH sensitive AMPS as monomers,AIBN as initiator and methylene-bis-acrylamide as crosslinking agent. The structure and morphology were characterized by the infrared（ IR） and scanning electron microscope（ SEM）,and effect of various factors on swelling ratio of hydrogel was investigated. Results showed that the water swelling rate of chitosan hydrogel was up to 95% when the monomer ratio of NIPAM ∶ AMPS was 6 ∶ 4,initiating agent was 4%,crosslinking agent dosage was 4% and polymerization temperature was about 45 ℃. Chitosan hydrogel with properties of thermo-sensitive and pH-sensitive has broad application prospects in the fields of drug controlled release,tissue engineering,anti-coagulation materials and so on.