环氧季铵盐对明胶的阳离子化改性

碱性条件下,环氧季铵盐1,2-环氧丙基二甲基十二烷基氯化铵(EPQA)与明胶侧链的伯胺基、羟基反应,得到阳离子改性明胶EPQA-GE,核磁共振(~(13)C-NMR、~1H-NMR)及元素分析结果表明,精氨酸、赖氨酸的氨基以及羟脯氨酸的羟基参与了反应,季铵阳离子基团成功引入了明胶结构中。X射线衍射及差示扫描量热分析结果表明,明胶的微观相结构受阳离子含量的影响较大,引入的季铵离子越多,EPQA-GE的近程有序度越高。以水和乙二醇为标准液,测定了阳离子化程度不同的EPQA-GE膜的接触角,并应用Owens-Wendt方程计算了表面自由能,结果显示阳离子基团的引入增加了明胶的亲水性,且随着阳离子化程度增加,膜表面的亲水性增强。抗菌实验结果表明阳离子的引入增加了明胶的抗菌性,EPQA-GE对革兰氏阳性菌的抗菌效果优于对革兰氏阴性菌的抗菌性。

Cationization of Gelatin with Epoxy Quaternary Ammonium Salt

Cationic gelatin(EPQA-GE) was synthesized with epoxypropyl dodecyl dimethyl ammonium chloride (EPQA) and gelatin(GE) under alkaline condition.The results of 13C-NMR,1H-NMR and elemental analysis show that quaternary ammonium group is successfully grafted onto gelatin.The results of XRD and DSC show that the micro-structure of EPQA-GE is influenced by the cationic content,the short-range order increases with the grafted quaternary ammonium group increasing.The contact angles of EPQA-GE film with water and ethanediol were measured respectively and the surface free energy was calculated by Owens-Wendt equation.It indicates that the hydrophilic of gelatin increases with the grafted cationic group increasing.Compared with initial gelatin,GE has no antibacterial property totally,while EPQA-GE exhibits stronger antibacterial activity against gram-positive bacterium than against gram-negative bacterium,but barely antibacterial activity against mold.