Partner: P. von Tiedemann

Johannes Gutenberg University (DE)

Ostatnie publikacje
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)
140p.