巯基-迈克尔加成法合成温敏性PEG共聚物及凝胶化反应

Synthesis of Thermosensitive PEG Copolymers via Thiol - Michael Addition Reaction and the Gelation

摘要:

巯基-迈克尔加成反应由于条件温和、迅速、高效等优点，近年来成为生物医用高分子材料合成的热点之一。双丙烯酰氧基的聚乙二醇二丙烯酸酯（PEGDA）和双巯基的3,6-二氧杂-1,8-辛二硫醇（EDT）通过巯基-迈克尔加成形成了温敏性的PEG共聚物(poly(PEGDA-alt-EDT) )。增大PEGDA 的分子量相应提高poly(PEGDA600-alt-EDT)水溶液的临界溶液温度（LCST）。1HNMR 和GPC表征了共聚物的结构和分子量。在APS的引发下poly(PEGDA-alt-EDT)末端官能团进一步发生偶合-聚合形成温敏性PEG共聚物水凝胶。SEM、流变性能测试和平衡溶胀系数结果表明，poly(PEGDA-alt-EDT)水凝胶具有典型的三维孔洞结构、良好的流变性能、溶胀能力和温度响应性。

Abstract:

Thiol-Michael addition reaction has become one of the most popular reaction methods in the field of synthesis of biomedical polymer materials due to the advantages of mild conditions, rapid, efficient in recent years. Well defined thermosensitive polymers poly(PEGDA-alt-EDT) were prepared by thiol-Michael addition reaction between poly(ethylene glycol) diacrylates (PEGDA) and 2,2’-(ethylenedioxy)diethanethiol (EDT). These copolymers aqueous solution exhibit a lower critical solution temperature (LCST), which can be easily tuned by the length of PEG units. These thermosensitive polymers bear acryloyloxy and thiol reactive groups demonstrated by 1H NMR spectrum and molecular weight measured by GPC. The thermosensitive poly(PEGDA-Alt-EDT) hydrogel was further formed coupling-polymerization between the end functional groups of PEG copolymers under the initiation of APS. The results of SEM, rheology and equilibrium swelling coefficient show that the poly(PEGDA-Alt-EDT) hydrogel has a typical 3D microporous structure, hydrogel rheological properties, swelling capacity and temperature responsiveness.