聚乙二醇嵌段长碳链二酸共聚物的合成与酶降解研究

Synthesis and Enzymatic Degradation of Polyethylene Glycol Block Copolymers with Long-chain Diacid

采用长碳链癸二酸代替丁二酸与丁二醇以及不同含量的相对分子质量为200的聚乙二醇(PEG)嵌段共聚,得到了聚癸二酸丁二醇酯-聚乙二醇嵌段共聚物(PBSe-PEG),并采用核磁共振波谱仪、凝胶渗透色谱仪、差示扫描量分析仪、热重分析仪、广角X射线衍射仪等分析手段表征了嵌段共聚物的结构和性能,并且研究了固定化南极假丝酵母菌脂肪酶(简称脂肪酶N435)对PBSe-PEG的降解性。结果表明,几种PBSe-PEG是预期产物,其数均相对分子质量在5×104左右;PBSe-PEG与纯PBSe相比晶型结构相似;随着PEG含量增加,PBSe-PEG的熔融温度(Tm)和结晶温度(Tc)逐渐下降;相比PBS,脂肪酶N435对PBSe-PEG具有更好的降解性。

A copolymer （PBSe-PEG） was obtained from the polycondensation product of sebacic acid, PEG-200, and polyethylene glycol. The structure of PBSe-PEG was characterized by 1H-NMR; molecular weight and its distribution were tested by GPC; crystallinity and thermal properties of the copolymers were analyzed by WXRD, DSC and TGA, and the degradation property was tested by lipase N435. GPC gave a molecular weight about 5× 10^4 ; 1H-NMR proved that PBSe-PEG had a similar crystal structure to neat PBSe. With increasing content of PEG-200, both Tm and Tc of the copolymer decreased. Compared with PBS,lipase N435 catalyzed degradation of PBSe-PEG better.