TY  - JOUR
A1  - Schönemann, Eric
A1  - Koc, Julian
A1  - Aldred, Nick
A1  - Clare, Anthony S.
A1  - Laschewsky, André
A1  - Rosenhahn, Axel
A1  - Wischerhoff, Erik
T1  - Synthesis of Novel Sulfobetaine Polymers with Differing Dipole Orientations in Their Side Chains, and Their Effects on the Antifouling Properties
JF  - Macromolecular rapid communications
N2  - The impact of the orientation of zwitterionic groups, with respect to the polymer backbone, on the antifouling performance of thin hydrogel films made of polyzwitterions is explored. In an extension of the recent discussion about differences in the behavior of polymeric phosphatidylcholines and choline phosphates, a quasi-isomeric set of three poly(sulfobetaine methacrylate)s is designed for this purpose. The design is based on the established monomer 3-[N-2-(methacryloyloxy)ethyl-N,N-dimethyl]ammonio-propane-1-sulfonate and two novel sulfobetaine methacrylates, in which the positions of the cationic and the ionic groups relative to the polymerizable group, and thus also to the polymer backbone, are altered. The effect of the varied segmental dipole orientation on their water solubility, wetting behavior by water, and fouling resistance is compared. As model systems, the adsorption of the model proteins bovine serum albumin (BSA), fibrinogen, and lysozyme onto films of the various polyzwitterion surfaces is studied, as well as the settlement of a diatom (Navicula perminuta) and barnacle cyprids (Balanus improvisus) as representatives of typical marine fouling communities. The results demonstrate the important role of the zwitterionic group's orientation on the polymer behavior and fouling resistance.
KW  - antifouling
KW  - coatings
KW  - crosslinking
KW  - hydrophilic polymers
KW  - polyzwitterions
Y1  - 2019
U6  - https://doi.org/10.1002/marc.201900447
SN  - 1022-1336
SN  - 1521-3927
VL  - 41
IS  - 1
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Friess, Fabian
A1  - Lendlein, Andreas
A1  - Wischke, Christian
T1  - Photoinduced synthesis of polyester networks from methacrylate functionalized precursors: analysis of side reactions
JF  - Polymers for advanced technologies
N2  - Polyester networks can be prepared by ultraviolet (UV)-light-induced radical polymerization of methacrylate functionalized oligo(epsilon-caprolactone)s. The properties and functions of the obtained materials depend on defined network structures and may be altered, if crosslinking would occur by side reactions in other positions than the methacrylate endgroups. In order to explore whether and to which extent such side reactions occur, network synthesis as well as related model reactions were performed in the absence of photoinitiator. Hereby precursor structures (linear and four-arm star-shaped) and reaction conditions (in solution and in the melt) were varied. Unspecific side reactions were found only upon extensive UV irradiation for 60min (26 mW cm(-2)) with minor but detectable alterations of physicochemical properties of the networks. The analysis of model reactions suggested minor photolytic cleavage of ester bonds during polymer network synthesis. However, the effect of these side reactions on network properties and functions appeared to be less relevant than an incomplete precursor integration because of a too short UV irradiation for crosslinking. Copyright (c) 2014 John Wiley & Sons, Ltd.
KW  - poly(epsilon-caprolactone) methacrylate
KW  - crosslinking
KW  - excimer UV light
KW  - side reaction
KW  - photoinduced radical polymerization
Y1  - 2014
U6  - https://doi.org/10.1002/pat.3313
SN  - 1042-7147
SN  - 1099-1581
VL  - 25
IS  - 11
SP  - 1285
EP  - 1292
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Mazurek, P.
A1  - Yu, L.
A1  - Gerhard, Reimund
A1  - Wirges, Werner
A1  - Skov, A. L.
T1  - Glycerol as high-permittivity liquid filler in dielectric silicone elastomers
JF  - Journal of applied polymer science
N2  - A recently reported novel class of elastomers was tested with respect to its dielectric properties. The new elastomer material is based on a commercially available poly(dimethylsiloxane) composition, which has been modified by embedding glycerol droplets into its matrix. The approach has two major advantages that make the material useful in a dielectric actuator. First, the glycerol droplets efficiently enhance the dielectric constant, which can reach astonishingly high values in the composite. Second, the liquid filler also acts as a softener that effectively decreases the elastic modulus of the composite. In combination with very low cost and easy preparation, the two property enhancements lead to an extremely attractive dielectric elastomer material. Experimental permittivity data are compared to various theoretical models that predict relative permittivity changes as a function of filler loading, and the applicability of the models is discussed. (c) 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44153.
KW  - crosslinking
KW  - dielectric properties
KW  - elastomers
KW  - sensors and actuators
Y1  - 2016
U6  - https://doi.org/10.1002/app.44153
SN  - 0021-8995
SN  - 1097-4628
VL  - 133
PB  - Wiley-Blackwell
CY  - Hoboken
ER  -