| 1. | von Tiedemann P.♦, Maciol K.♦, Preis J.♦, Sajkiewicz P., Frey H.♦, Rapid one-pot synthesis of tapered star copolymers via ultra-fast coupling of polystyryllithium chain ends, Polymer Chemistry, ISSN: 1759-9954, DOI: 10.1039/C8PY01656A, Vol.10, No.14, pp.1762-1768, 2019 Streszczenie: Highly efficient stoichiometric coupling of sterically hindered polystyryllithium (PS-Li) chain ends was achieved using tetra[3-(chloro-dimethylsilyl)propyl]silane (TCDMSPS) as the linking agent. Based on the disparate reactivities of isoprene (I, rI = 11.0) and styrene (S, rS = 0.049) in the anionic copolymerization in nonpolar media, poly(isoprene0.5-grad-styrene0.5) (P(I0.5-grad-S0.5)) tapered 4-arm star copolymers were synthesized in only two steps. The tapered 4-arm star copolymers (Mwtargeted = 40 to 160 kg mol^-1) were synthesized with high star functionalities f (Mw,star/Mw,arm = 3.68 - 3.98), low dispersity (Ð = 1.06 - 1.15) and minimal residual precursor content (2-8 wt%), avoiding fractionation or other purification methods. Coupling kinetics measurements revealed that for the synthesis of polystyrene (PS) 4-arm stars (12 kg mol^-1) a coupling efficiency of 98% was already achieved within 2 minutes. All star polymers were analyzed by size exclusion chromatography (SEC) viscometry with universal calibration (UC) as well as NMR spectroscopy. Well-defined nanofibers from the tapered copolymer stars were obtained via electrospinning. Afiliacje autorów: | von Tiedemann P. | - | Johannes Gutenberg University (DE) | | Maciol K. | - | Johannes Gutenberg University (DE) | | Preis J. | - | PSS Polymer Standards Service GmbH (DE) | | Sajkiewicz P. | - | IPPT PAN | | Frey H. | - | Johannes Gutenberg University (DE) |
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