Synthesis, Functionalization, and Controlled Degradation of High Molecular Weight Polyester from Itaconic Acid via ADMET Polymerization
Synthesis, Functionalization, and Controlled Degradation of High Molecular Weight Polyester from Itaconic Acid via ADMET Polymerization
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DOI：
10.1021/ma5020066
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发表时间：
2014-11-25
期刊：
影响因子：
5.5
通讯作者：
Li, Zi-Chen
中科院分区：
文献类型：
--
作者：
Lv, An;Li, Zi-Long;Li, Zi-Chen
我们报道了一种基于衣康酸(IA)和10-十一烯醇的高相对分子质量聚酯的合成、官能化和可控降解的简便策略。以IA和10-十一烯醇为原料，经酯化反应合成了双烯单体衣康酸二(10-十一烯)酯(DUI)。在GRubbs第一代催化剂(G-I)的作用下，DUI的非环二烯歧化(ADMET)聚合得到了高相对分子质量聚酯(PEIA：P1和P2)。用3-硫醇(MP)、苯硫醇(BM)、十二烷基硫醇(DM)和哌啶(PI)与衣康酸乙烯基进行Michael加成反应，对P1进行了修饰。核磁共振和凝胶渗透色谱表征表明，三种硫醇和PI均实现了不降解聚酯的定量后聚合改性。还成功地用MP和PI对P1进行了一锅连续修饰。用热重分析(TGA)和差示扫描量热法(DSC)研究了改性聚酯的热性能。所有的改性聚酯都是半结晶的，玻璃化转变温度和熔融温度都受改性侧基的影响。在详细的模型反应研究的基础上，实现了衣康酸乙烯基对伯胺(仲丁胺和3-戊胺)的可控修饰，而不需要进行分子内环化反应。因此，用仲丁胺对P1进行改性，合成了一种仲胺功能化聚酯(P1-BA/DM)，该聚酯在低温下稳定，但在固体或溶液中通过分子内环化自降解，在高温下形成五元内酰胺。这是一种降解率可控的新型自降解性聚酯。
We report a facile strategy for the synthesis, functionalization, and controlled degradation of high molecular weight polyesters based on itaconic acid (IA) and 10-undecenol. A diene monomer, di(10-undecenyl) itaconate (DUI), was synthesized from IA and 10-undecenol by esterification reaction. The acyclic diene metathesis (ADMET) polymerization of DUI was conducted with Grubbs first-generation catalyst (G-I) to afford high molecular weight polyesters (PEIA: P1 and P2). Modification of P1 with three mercaptans (3-mercapto-1,2-propanediol (MP), benzyl mercaptan (BM), and dodecyl mercaptan (DM)) and piperidine (PI) via Michael addition reaction with the itaconate vinyl groups was performed. Quantitative postpolymerization modifications with no degradation of the polyesters were achieved for all the three mercaptans and PI as revealed by NMR and GPC characterizations. One-pot sequential modification of P1 with MP and PI was also successfully conducted. Thermal properties of the modified polyesters were studied by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). All the modified polyesters are semicrystalline with variable glass transition and melting temperatures which are affected by the modified side groups. Based on a detailed model reaction study, controlled modification of the itaconate vinyl groups with primary amines (sec-butylamine and 3-pentanamine) without intramolecular cyclization was achieved. Thus, sec-butylamine was used to modify P1 to generate a secondary amine functionalized polyester (P1-BA/DM) which was stable at low temperature but undergone self-degradation in solid or solution via intramolecular cyclization with the formation of a five-membered lactam at elevated temperatures. This is a new kind of self-degradable polyester with controllable degradation rates.