Lonnecker Alexander T, Lim Young H, Wooley Karen L
Departments of Chemistry, Chemical Engineering, and Materials Science and Engineering, and Laboratory for Synthetic-Biologic Interactions, Texas A&M University, College Station, Texas 77842, United States.
ACS Macro Lett. 2017 Jul 18;6(7):748-753. doi: 10.1021/acsmacrolett.7b00362. Epub 2017 Jun 26.
Herein, we demonstrate the synthesis of a bicyclic carbonate monomer of a d-glucal derivative, which originated from the natural product d-glucose, in an efficient three-step procedure and its ring-opening polymerization (ROP), initiated by 4-methylbenzyl alcohol, via organocatalysis. The ROP behavior was studied as a function of time, catalyst type, and catalyst concentration by using size exclusion chromatography (SEC) and nuclear magnetic resonance (NMR) spectroscopy. Using a cocatalyst system of 1,8-diazabicyclo[5.4.0]undec-7-ene and 1-(3,5-bis(trifluoromethyl)phenyl)-3-cyclohexyl-2-thiourea (5 mol %) afforded poly(d-glucal-carbonate) (PGCC) with almost complete monomer conversion (ca. 99%) within 1 min, as analyzed by H NMR spectroscopy, and a monomodal SEC trace with dispersity of 1.13. The resulting PGCCs exhibited amorphous characteristics with a relatively high glass transition temperature at ca. 69 °C and onset decomposition temperature at ca. 190 °C, as analyzed by differential scanning calorimetry and thermogravimetric analysis, respectively. This new type of potentially degradable polymer system represents a reactive functional polymer architecture.
在此，我们展示了一种由天然产物d -葡萄糖衍生而来的d -葡糖醛衍生物的双环碳酸酯单体的高效三步合成方法及其通过有机催化由4 -甲基苄醇引发的开环聚合（ROP）。通过尺寸排阻色谱法（SEC）和核磁共振（NMR）光谱研究了ROP行为随时间、催化剂类型和催化剂浓度的变化。使用1,8 -二氮杂双环[5.4.0]十一碳- 7 -烯和1 -（3,5 -双（三氟甲基）苯基）- 3 -环己基- 2 -硫脲（5 mol%）的助催化剂体系，通过1H NMR光谱分析，在1分钟内可实现几乎完全的单体转化率（约99%），得到分散度为1.13的单峰SEC曲线的聚（d -葡糖醛碳酸酯）（PGCC）。通过差示扫描量热法和热重分析分别分析，所得的PGCC表现出非晶态特征，玻璃化转变温度相对较高，约为69°C，起始分解温度约为190°C。这种新型的潜在可降解聚合物体系代表了一种反应性功能聚合物结构。
