柱状多肽分子刷的合成与表征

【作者】 张磊；

【导师】 张阿方；

【作者基本信息】 郑州大学 ， 材料学， 2006， 硕士

【摘要】 本文通过“胺”引发氨基酸酸酐开环聚合机理及“表面接枝”路线合成柱状多肽分子刷。实验总体步骤如下：(1)合成聚合单元中含有被保护氨基的超高分子量的聚合物；(2)在三氟乙酸作用下脱去氨基上的保护基团制备大分子引发剂；(3)利用大分子引发剂引发谷氨酸酸酐聚合制备多肽分子刷；(4)利用核磁、凝胶色谱柱、原子力显微镜对分子刷进行表征；利用这种技术成功地合成了分别以超高分子量的PHG、PME为主链的柱状多肽分子刷(聚合度超过1 0000)及主链为PHL的双层多肽分子刷(聚合度超过10000)；同时，也成功地合成了主链为聚赖氨酸、侧链为聚谷氨酸的多肽分子刷(聚合度约5000)；并研究了不同引发剂在不同条件下引发谷氨酸酸酐的聚合情况。由于侧链聚合物分子间及分子内的相互作用力致使这些主链刚、柔性均不相同的分子刷在一般溶剂不能够溶解，只有在较高的温度下才能溶解于二甲基甲酰胺、二甲基亚砜中。核磁谱图表明，在化学位移1.5-2.5范围之内，明显地表现出聚谷氨酸的特征。利用原子力显微镜研究表明，这些分子刷在云母片上呈现“蠕虫”状单分子结构。更多还原

【Abstract】 The ring opening polymerization of aminoacid N-carboxyanhydrides ( NCAs) was applied to the synthesis of cylindrical polypeptide brushes by using the " grafting from" technique. The procedure included the following steps: (1) thermal polymerization of ME、HG、HL gave super-high molar mass mains with pendant protected amine groups; (2) subsequent removal of tert-butoxycarbonyl groups (Boc) of PME、 PHG、 PHL yielded polyinitiators (PME-BoC、 PHL-Boc、 PHG-Boc); (3) The ring opening polymerization of γ-benzyl-L-glutamate NCA using PME-Boc、 PHL-Boc、 PHG-Boc as polyinitiators yield cylindrical polypeptide brushes with poly-glutamate as side chains. (4) ~1HNMR、GPC、AFM investigation of the samples; By using this technique, the cylindrical polypeptide brushes with super-high molar mass as backbones (DP>10000) and poly-glutamate as side chains were successfully synthesized.The cylindrical brushes with Poly-Lysine (DP>5000) as backbones and Poly-glutamate as side chains were also synthesized. Meanwhile the polymerization of Y-benzyl-L-glutamate NCA by polyinitiators were studied respectively. Because of intermolecular hydrogen bond and intramolecular hydrogen bond these cylindrical brushes are poor soluble in common solvents except DMF and DMSO at high temperature. The peaks at 1.5-2.5 assigned to poly-glutamate were confirmed by ~1HNMR. The cylindrical brushes were then further characterized by scanning force microscopy. Single wormlike unimolecular nanocylinders were visualized on a mica surface.更多还原