含有氨基酸残基的可降解聚酯酰胺的合成与表征-化学工程专业论文.docxVIP

PAGE PAGE 1 摘 要 为了改善聚 ε-己内酯（poly(ε-caprolactone), PCL）的亲水性和降解性，本 论文分别将四种天然氨基酸（L-丙氨酸、L-亮氨酸、L-谷氨酸、L-赖氨酸）引 入到 PCL 聚合物中，合成了四种含有氨基酸残基的聚酯酰胺。 将天然氨基酸引入到聚对二氧环己酮（poly(p-dioxanone), PPDO）和 PCL 中，首先要合成相应的中间体或齐聚物。本论文选择氨基酸钠游离的氨基引发 对二氧环己酮（p-dioxanone, PDO）和 ε-己内酯（ε-caprolactone, CL）单体开环， 再经过酸化得到四种酯肽中间体。考察了合成这些中间体的条件，并通过 1H-NMR 和 FT-IR 对其结构行进了表征。当氨基酸钠和 CL 单体投料比为 1:4， 在 140oC 条件下，氨基酸钠反应完全，为合成分子量分布较窄的氨基酸封端 PCL 齐聚物准备了条件。1H-NMR 和 FT-IR 表明在此条件下氨基酸钠能够有效的引 发 PDO 和 CL 开环，反应生成了相应的酯肽结构。通过控制氨基酸钠和 CL 的 投料比，合成了三种不同分子量的 L-亮氨酸和 L-丙氨酸封端的 PCL 齐聚物。 在此基础之上，选择不同的氨基酸钠合成了含有不同氨基酸残基的 PCL 齐 聚物，通过 1H-NMR 和 GPC 对其进行了表征。以这些齐聚物为大分子单体， 以 HDI 为扩链剂，合成了分子量较高的聚酯酰胺。通过 FT-IR、水接触角、水 吸收率和降解实验对这些聚酯酰胺进行了表征。实验结果表明：经氨基酸改性 的 PCL 亲水性和降解性得到了改善。其中，含有 L-赖氨酸残基的聚酯酰胺亲 水性最强，降解速率最快。 关键词： 酯肽，氨基酸，聚 ε-己内酯，聚酯酰胺 ABSTRACT In order to improve the hydrophilic and degradation of poly(ε-caprolactone)[PCL], four amino acids (L-alanine, L-leucine, L-glutamic acid and L-lysine) were introduced into PCL, and four poly(ester-amide)s containing L-amino acid residue were synthesized. To impart the L-amino acide residues to poly(p-dioxanone)[PPDO] and PCL, the preparation of intermediate or oligomer was critical. The ring-opening of PDO and CL proceeded by the primary amino group of amino acid sodium, and four depsipeptides were prepared by subsequent acidification. Optimal conditions of this reaction have been studied, and the structure of depsipeptide was confirmed by 1H-NMR and FT-IR. At 140oC when the feed ratio of amino acid sodium and CL was 1:4, no amino acid was left, which contributed to the preparation of amino acid-terminated PCL with narrow molecular weight distribution. The 1H-NMR and FT-IR spectra indicated that the amino acid sodium effectively initiated the ring-opening of PDO and CL, and the depsipeptides were prepared. By controling the feed ratio of amino acid sodium and CL, L-leucine-terminated-PCL and L-alanine-terminated-PCL oligomers with different molecular weight were prepared. Based on that, four P