TY  - JOUR
A1  - Weber, Nancy
A1  - Tiersch, Brigitte
A1  - Unterlass, Miriam M.
A1  - Heilig, Anneliese
A1  - Tauer, Klaus
T1  - "Schizomorphic" Emulsion Copolymerization Particles
JF  - Macromolecular rapid communications
N2  - Cryo-electron microscopy, atomic force microscopy, and light microscopy investigations provide experimental evidence that amphiphilic emulsion copolymerization particles change their morphology in dependence on concentration. The shape of the particles is spherical at solids content above 1%, but it changes to rod-like, ring-like, and web-like structures at lower concentrations. In addition, the shape and morphology of these particles at low concentrations are not fixed but very flexible and vary with time between spheres, flexible pearlnecklace structures, and stretched rods.
KW  - amphiphilic particles
KW  - emulsion polymerization
KW  - morphology
Y1  - 2011
U6  - https://doi.org/10.1002/marc.201100491
SN  - 1022-1336
VL  - 32
IS  - 23
SP  - 1925
EP  - 1929
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Yuan, Jiayin
A1  - ten Brummelhuis, Niels
A1  - Junginger, Mathias
A1  - Xie, Zailai
A1  - Lu, Yan
A1  - Taubert, Andreas
A1  - Schlaad, Helmut
T1  - Diversified applications of chemically modified 1,2-Polybutadiene
JF  - Macromolecular rapid communications
N2  - Commercially available 1,2-PB was transformed into a well-defined reactive intermediate by quantitative bromination. The brominated polymer was used as a polyfunctional macroinitiator for the cationic ring-opening polymerization of 2-ethyl-2-oxazoline to yield a water-soluble brush polymer. Nucleophilic substitution of bromide by 1-methyl imidazole resulted in the formation of polyelectrolyte copolymers consisting of mixed units of imidazolium, bromo, and double bond. These copolymers, which were soluble in water without forming aggregates, were used as stabilizers in the heterophase polymerization of styrene and were also studied for their ionic conducting properties.
KW  - emulsion polymerization
KW  - polybutadiene
KW  - polyelectrolytes
KW  - polymer modification
KW  - ring-opening polymerization
Y1  - 2011
U6  - https://doi.org/10.1002/marc.201100254
SN  - 1022-1336
VL  - 32
IS  - 15
SP  - 1157
EP  - 1162
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Schlappa, Stephanie
A1  - Bressel, Lena
A1  - Reich, Oliver
A1  - Münzberg, Marvin
T1  - Advanced particle size analysis in high-solid-content polymer dispersions using photon density wave spectroscopy
JF  - Polymers
N2  - High-solid-content polystyrene and polyvinyl acetate dispersions of polymer particles with a 50 nm to 500 nm mean particle diameter and 12-55% (w/w) solid content have been produced via emulsion polymerization and characterized regarding their optical and physical properties. Both systems have been analyzed with common particle-size-measuring techniques like dynamic light scattering (DLS) and static light scattering (SLS) and compared to inline particle size distribution (PSD) measurements via photon density wave (PDW) spectroscopy in undiluted samples. It is shown that particle size measurements of undiluted polystyrene dispersions are in good agreement between analysis methods. However, for polyvinyl acetate particles, size determination is challenging due to bound water in the produced polymer. For the first time, water-swelling factors were determined via an iterative approach of PDW spectroscopy error (X-2) minimization. It is shown that water-swollen particles can be analyzed in high-solid-content solutions and their physical properties can be assumed to determine the refractive index, density, and volume fraction in dispersion. It was found that assumed water swelling improved the reduced scattering coefficient fit by PDW spectroscopy by up to ten times and particle size determination was refined and enabled. Particle size analysis of the water-swollen particles agreed well with offline-based state-of-the-art techniques.
KW  - emulsion polymerization
KW  - multiple light scattering
KW  - photon density wave
KW  - spectroscopy
KW  - particle sizing
KW  - swelling of polymers
Y1  - 2023
U6  - https://doi.org/10.3390/polym15153181
SN  - 2073-4360
VL  - 15
IS  - 15
PB  - MDPI
CY  - Basel
ER  -