Macromolecular Rapid Communications
Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Editors: Kirsten Severing , Stefan Spiegel
Online ISSN: 1521-3927
Materials Science Weekly Newsletter
Recently Published Articles
- Synthesis and Sequential Deprotection of Triblock Copolypept(o)ides Using Orthogonal Protective Group Chemistry
Philipp Heller, Benjamin Weber, Alexander Birke and Matthias Barz
Article first published online: 30 OCT 2014 | DOI: 10.1002/marc.201400466
The synthesis of orthogonally deprotectable triblock copolypept(o)ides is described. These polymers are based on polysarcosine, poly-N-ε-t-butyloxycarbonyl-l-lysine, and poly-N-ε-t-trifluoroacetyl-l-lysine. They are prepared by ring-opening polymerization of the corresponding α-amino acid N-carboxyanhydrides (NCAs). For the synthesis of N-ε-t-butyloxycarbonyl-l-lysine (lysine(Boc)) NCAs, an acid-free method using trimethylsilylchloride/triethylamine as hydrochloric acid (HCl) scavengers is presented.
- Zirconium-Allyl Complexes as Resting States in Zirconocene-Catalyzed α-Olefin Polymerization
Valentina N. Panchenko, Dmitrii E. Babushkin and Hans H. Brintzinger
Article first published online: 30 OCT 2014 | DOI: 10.1002/marc.201400444
Formation of zirconocene cations with Zr-bound allylic chain ends is shown to be a general phenomenon when olefins are polymerized with a zirconocene catalyst. The rate and the extent of Zr-allyl formation depend on the kinds of zirconocene precatalysts and activators used for the catalyst system considered.
- Direct Access to Dithiobenzoate RAFT Agent Fragmentation Rate Coefficients by ESR Spin-Trapping
Kayte Ranieri, Guillaume Delaittre, Christopher Barner-Kowollik and Thomas Junkers
Article first published online: 30 OCT 2014 | DOI: 10.1002/marc.201400518
The activation energy of the dithiobenzoates RAFT (reversible addition–fragmentation chain transfer) intermediate fragmentation rate coefficient is determined via ESR (electron spin resonance) spin trapping experiments, which unambiguously demonstrate that these intermediate radicals are associated with a comparatively high stability as predicted by theoretical calculations.
- Core–Shell–Shell and Hollow Double-Shell Microgels with Advanced Temperature Responsiveness
Janine Dubbert, Katja Nothdurft, Matthias Karg and Walter Richtering
Article first published online: 29 OCT 2014 | DOI: 10.1002/marc.201400495
The synthesis of doubly thermoresponsive hollow microgels with two concentric shells is reported. Unique swelling properties are observed for the particles at different temperatures: at temperatures below 32 °C, both shells are swollen, at temperatures between 32 °C and 42 °C only the inner shell, and above 42 °C both polymer shells are collapsed.
- Synthesis of Poly(poly(ethylene glycol) methacrylate)–Polyisobutylene ABA Block Copolymers by the Combination of Quasiliving Carbocationic and Atom Transfer Radical Polymerizations
Ákos Szabó, Györgyi Szarka and Béla Iván
Article first published online: 29 OCT 2014 | DOI: 10.1002/marc.201400469
By combining quasiliving carbocationic and atom transfer radical polymerization (ATRP), novel PPEGMA-PIB-PPEGMA ABA-type block copolymers with the comb-shaped poly(poly(ethylene glycol) methacrylate) (PPEGMA) outer blocks are synthesized via ATRP of poly(ethylene glycol) methacrylate (PEGMA) macromonomers with various chain length initiated by 2-bromoisobutyrate-telechelic linear polyisobutylene (PIB) as macroinitiator.