Christine Schilli

Bio: Christine Schilli is an academic researcher from University of Bayreuth. The author has contributed to research in topics: Chain transfer & Lower critical solution temperature. The author has an hindex of 5, co-authored 5 publications receiving 1096 citations. Previous affiliations of Christine Schilli include University of Washington.

A New Double-Responsive Block Copolymer Synthesized via RAFT Polymerization: Poly(N-isopropylacrylamide)-block-poly(acrylic acid)

Abstract: Poly(N-isopropylacrylamide)-block-poly(acrylic acid), PNIPAAm-b-PAA, with low polydispersity was prepared by reversible addition−fragmentation chain transfer (RAFT) polymerization in methanol. The block copolymers respond to both temperature and pH stimuli. The behavior of the double-responsive block copolymers in solution was investigated by dynamic light scattering, temperature-sweep NMR, cryogenic transmission electron microscopy, and IR spectroscopy. The block copolymers form micelles in aqueous solutions in dependence of pH and temperature. Cloud point measurements indicated the formation of larger aggregates at pH 4.5 and temperatures above the lower critical solution temperature (LCST) of PNIPAAm. The solution behavior is strongly influenced by hydrogen bonding interactions between the NIPAAm and acrylic acid blocks.

Benzyl and Cumyl Dithiocarbamates as Chain Transfer Agents in the RAFT Polymerization of N-Isopropylacrylamide. In Situ FT-NIR and MALDI−TOF MS Investigation

Abstract: The principles of RAFT polymerization were applied to the polymerization of N-isopropylacrylamide (NIPAAm), which was carried out in the presence of the dithiocarbamates benzyl 1-pyrrolecarbodithioate and cumyl 1-pyrrolecarbodithioate, respectively, as chain transfer agents in 1,4-dioxane at 60 °C. A kinetic investigation using in situ FT-NIR spectroscopy shows very long induction periods which depend on the nature and concentration of the chain transfer agent. The resulting polymers have polydispersity indices Mw/Mn < 1.3 and have been investigated by MALDI−TOF mass spectrometry, GPC, NMR, and UV spectroscopy. The expected end group signals for chain transfer agent (CTA) and initiator could be identified together with fragmentation of the dithioester end group under MALDI conditions. The number-average molecular weights obtained by MALDI−TOF MS are significantly lower than those obtained by GPC with polystyrene calibration. With the use of the abovementioned dithiocarbamates, new thiocarbonylthio compoun...

Living radical polymerization by the RAFT process

Abstract: This paper presents a review of living radical polymerization achieved with thiocarbonylthio compounds [ZC(=S)SR] by a mechanism of reversible addition–fragmentation chain transfer (RAFT). Since we first introduced the technique in 1998, the number of papers and patents on the RAFT process has increased exponentially as the technique has proved to be one of the most versatile for the provision of polymers of well defined architecture. The factors influencing the effectiveness of RAFT agents and outcome of RAFT polymerization are detailed. With this insight, guidelines are presented on how to conduct RAFT and choose RAFT agents to achieve particular structures. A survey is provided of the current scope and applications of the RAFT process in the synthesis of well defined homo-, gradient, diblock, triblock, and star polymers, as well as more complex architectures including microgels and polymer brushes.

Living Radical Polymerization by the RAFT Process - A Second Update

Abstract: This paper provides a third update to the review of reversible deactivation radical polymerization (RDRP) achieved with thiocarbonylthio compounds (ZC(=S)SR) by a mechanism of reversible addition-fragmentation chain transfer (RAFT) that was published in June 2005 (Aust. J. Chem. 2005, 58, 379). The first update was published in November 2006 (Aust. J. Chem. 2006, 59, 669) and the second in December 2009 (Aust. J. Chem. 2009, 62, 1402). This review cites over 700 publications that appeared during the period mid 2009 to early 2012 covering various aspects of RAFT polymerization which include reagent synthesis and properties, kinetics and mechanism of polymerization, novel polymer syntheses, and a diverse range of applications. This period has witnessed further significant developments, particularly in the areas of novel RAFT agents, techniques for end-group transformation, the production of micro/nanoparticles and modified surfaces, and biopolymer conjugates both for therapeutic and diagnostic applications.

Macromolecular design via réversible addition-fragmentation chain transfer (RAFT)/Xanthates (MADIX) polymerization

Abstract: Among the living radical polymerization techniques, reversible addition–fragmentation chain transfer (RAFT) and macromolecular design via the interchange of xanthates (MADIX) polymerizations appear to be the most versatile processes in terms of the reaction conditions, the variety of monomers for which polymerization can be controlled, tolerance to functionalities, and the range of polymeric architectures that can be produced. This review highlights the progress made in RAFT/MADIX polymerization since the first report in 1998. It addresses, in turn, the mechanism and kinetics of the process, examines the various components of the system, including the synthesis paths of the thiocarbonyl-thio compounds used as chain-transfer agents, and the conditions of polymerization, and gives an account of the wide range of monomers that have been successfully polymerized to date, as well as the various polymeric architectures that have been produced. In the last section, this review describes the future challenges that the process will face and shows its opening to a wider scientific community as a synthetic tool for the production of functional macromolecules and materials. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43:5347–5393, 2005