嵌段共聚物OSM_1-PCLA-PEG-PCLA-OSM_1的合成及其pH和温度敏感性

Synthesis and pH and Temperature Sensitive Properties of OSM_1-PCLA-PEG-PCLA-OSM_1 Block Copolymers

采用开环聚合法和自由基聚合法合成了生物可降解嵌段共聚物OSM1-PCLA-PEG-PCLA-OSM1,并对其进行了结构表征.采用荧光分光光度计和激光粒度仪对共聚物溶液临界胶束浓度(CMC)和粒径大小及分布进行了考察,研究了温度和pH对共聚物胶束形成的影响.相转变过程研究结果表明,共聚物溶液具有pH和温度双重敏感性.共聚物溶液在一定温度和pH条件下可发生溶液-凝胶相转变.

A new kind of biodegradable pH and temperature sensitive block copolymers were synthesized by ring-opening and conventional free radical polymerizations. The chemical structure of OSM1-PCLA-PEG- PCLA-OSM1 block copolymers was characterized via FTIR and ^1H NMR. Critical micelle concentration and particle size distribution were studied by fluorospectrophotometer and laser size detector to verify the copolymers micelle formation. The results of sol-gel transition show that the block copolymers solution possesses both pH and temperature sensitive properties. Different block copolymer solutions can form a stable gel obviously at certain temperature. OSM1-PCLA-PEG-PCLA-OSM1 block copolymers could be potential intelligent polymers materials for drug delivery system because of its pH and temperature sensitive properties.