Acid-Labile Surfactants Based on Poly(ethylene glycol), Carbon Dioxide and Propylene Oxide: Miniemulsion Polymerization and Degradation Studies

Polymers

Markus Scharfenberg¹  Holger Frey¹  Sarah Wald²  Frederik R. Wurm² 

[1] 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;

关键词: polycarbonate;    CO2;    surfactant;    miniemulsion polymerization;    degradation;    nanoparticle;   

DOI  :  10.3390/polym9090422

来源: DOAJ

【 摘 要 】

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 (R,R)-(salcy)-CoOBzF5 as a catalyst in a solvent-free one-pot procedure. The amphiphilic surfactants were prepared with molecular weights (Mn) between 2800 and 10,000 g·mol−1 with narrow molecular weight distributions (1.03–1.09). The copolymers were characterized using 1H-, 13C- 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·mL−1). 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.

【 授权许可】

Unknown