Scharfenberg Markus, Wald Sarah, Wurm Frederik R, Frey Holger
Institute of Organic Chemistry, Duesbergweg 10-14, Johannes Gutenberg University Mainz, 55128 Mainz, Germany.
Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
Polymers (Basel). 2017 Sep 6;9(9):422. doi: 10.3390/polym9090422.
Partially degradable, nonionic AB and ABA type di- and triblock copolymers based on poly(propylene carbonate) and poly(ethylene glycol) blocks were synthesized via immortal copolymerization of carbon dioxide and propylene oxide, using mPEG or PEG as a macroinitiator, and (,)-(salcy)-CoOBzF₅ as a catalyst in a solvent-free one-pot procedure. The amphiphilic surfactants were prepared with molecular weights () between 2800 and 10,000 g·mol¹ with narrow molecular weight distributions (1.03⁻1.09). The copolymers were characterized using ¹H-, C- and DOSY-NMR spectroscopy and size exclusion chromatography (SEC). Surface-active properties were determined by surface tension measurements (critical micelle concentration, CMC; CMC range: 1⁻14 mg·mL¹). Degradation of the acid-labile polycarbonate blocks was investigated in aqueous solution using online ¹H-NMR spectroscopy and SEC. The amphiphilic polymers were used as surfactants in a direct miniemulsion polymerization for poly(styrene) (PS) nanoparticles with mean diameter of 270 to 940 nm. The usage of an acid-triggered precipitation of the emulsion simplified the separation of the particles from the surfactant and purification of the nanoparticles.
基于聚碳酸丙烯酯和聚乙二醇嵌段的部分可降解非离子型AB和ABA型二嵌段及三嵌段共聚物，通过二氧化碳与环氧丙烷的活性共聚反应合成。以甲氧基聚乙二醇（mPEG）或聚乙二醇（PEG）为大分子引发剂，（，）-（水杨醛）-CoOBzF₅为催化剂，在无溶剂的一锅法中进行反应。制备的两亲性表面活性剂分子量（）在2800至10000 g·mol⁻¹之间，分子量分布较窄（1.03⁻1.09）。通过¹H-、¹³C-和DOSY-NMR光谱以及尺寸排阻色谱（SEC）对共聚物进行表征。通过表面张力测量（临界胶束浓度，CMC；CMC范围：1⁻14 mg·mL⁻¹）测定表面活性性能。使用在线¹H-NMR光谱和SEC研究了酸不稳定聚碳酸酯嵌段在水溶液中的降解情况。两亲性聚合物用作直接细乳液聚合制备聚（苯乙烯）（PS）纳米颗粒的表面活性剂，所得纳米颗粒平均直径为270至940 nm。乳液的酸引发沉淀法简化了颗粒与表面活性剂的分离以及纳米颗粒的纯化过程。
