TY  - JOUR
A1  - Jelicic, Aleksandra
A1  - Yasin, Muttaqin
A1  - Beuermann, Sabine
T1  - Toward the description and prediction of solvent induced variations in Methacrylate Propagation Rate Coefficients on the basis of Solvatochromic Parameters
JF  - Macromolecular reaction engineering
N2  - Benzyl methacrylate (BzMA) propagation rate coefficients, k(p), were determined in ionic liquids and common organic solvents via pulsed-laser polymerizations with subsequent polymer analysis by size-exclusion chromatography (PLP-SEC). The aim of the work is to gain a deeper understanding of the solvent influence on k(p) and to develop a general correlation between solvent-induced variations in k(p) and solvent properties. Applying a linear solvation energy relationship (LSER), which correlates k(p) to solvent solvatochromic parameters, suggests that dipolarity/polarizability determines the solvent influence on k(p). To compare the solvent influence on BzMA k(p) with data for methyl methacrylate, hydroxypropyl methacrylate, and 2-ethoxyethyl methacrylate normalized k(p) data were treated by a single LSER, providing a universal treatment of the solvent influence on the propagation kinetics of the four monomers. Further, the predictive capabilities of this universal correlation were tested with additional monomers from the methacrylate family.
KW  - ionic liquid
KW  - kinetics (polym.)
KW  - radical polymerization
KW  - solvent influence
Y1  - 2011
U6  - https://doi.org/10.1002/mren.201000058
SN  - 1862-832X
VL  - 5
IS  - 5-6
SP  - 232
EP  - 242
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Fechner, Mabya
A1  - Koetz, Joachim
T1  - Potentiometric behavior of Polyampholytes based on N,N'-diallyl-N,N'-dimethylammonium chloride and maleamic acid derivatives
JF  - Macromolecular chemistry and physics
N2  - Strongly alternating copolymers (PalH, PalPh, PalPhBisCarb) composed of N,N'-diallyl-N,N'-dimethyl-ammonium chloride (DADMAC) and maleamic acid derivatives (MAD) are synthesized by a water-based free radical copolymerization using 4,4-azobis(4-cyanovaleric acid) (V501) as the initiator. The structure of the copolymers is verified by 1H-NMR, elemental analysis, and thermogravimetric measurements, and the physicochemical properties are investigated by viscometric and potentiometric techniques. Potentiometric titration curves show that the acidity of the carboxylic groups strongly depends on the degree of dissociation and the ionic strength. Since all copolymers behave as polycations at low degree of dissociation, a transition from an extended chain to a coil conformation can be identified by reaching the isoelectric point (IEP).
KW  - acidity constants
KW  - radical polymerization
KW  - polyampholytes
KW  - viscosity
KW  - conformational transitions
Y1  - 2011
U6  - https://doi.org/10.1002/macp.201100532
SN  - 1022-1352
VL  - 212
IS  - 24
SP  - 2691
EP  - 2699
PB  - Wiley-Blackwell
CY  - Malden
ER  -