Multiarm Polycarbonate Star Polymers with a Hyperbranched Polyether Core from CO2 and Common Epoxides
Multiarm star copolymers, consisting of hyperbranched poly(ethylene oxide) (hbPEO) or poly(butylene oxide) (hbPBO) polyether copolymers with glycerol branching points as a core, and linear aliphatic polycarbonate arms generated from carbon dioxide (CO2) and epoxide monomers, were synthesized via a “core-first” approach in two steps. First, hyperbranched polyether polyols were prepared by anionic copolymerization of ethylene oxide or 1,2-butylene oxide with 8–35% glycidol with molecular weights between 800 and 389,000 g·mol–1. Second, multiple arms were grown via immortal copolymerization of CO2 with propylene oxide or 1,2-butylene oxide using the polyether polyols as macroinitiators and (R,R)-(salcy)-CoCl as a catalyst in a solvent-free procedure. Molecular weights up to 812,000 g·mol–1 were obtained for the resulting multiarm polycarbonates, determined by online viscometry with universal calibration and 1H NMR. Comparing the synthesis of different multiarm star polycarbonates, a combination of a highly r...
Markus Scharfenberg; Jan Seiwert; Maximilian Scherger; Jasmin Preis; Moritz Susewind; Holger Frey
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Rohm and Haas Powder Coatings is delighted to announce that its Reading, Pennsylvania, facility is the first site in the world to receive the RCMS® Site Certification awarded by the American Chemical Council (ACC).
When Raj Gupta, Chairman and CEO of Rohm and Haas Company, became Chairman ... more