TY  - JOUR
A1  - Möller, Eleonore
A1  - Beuermann, Sabine
T1  - Homogeneous phase copolymerizations of vinylidene fluoride and hexafluoropropene in supercritical carbon dioxide
JF  - Macromolecular reaction engineering
N2  - Copolymerizations of vinylidene fluoride (VDF) and hexafluoropropene (HFP) were carried out in homogeneous phase with supercritical carbon dioxide up to complete VDF conversion using conventional peroxide initiators. The HFP monomer feed ratios, f(HFP), were varied between 0.65 and 0.20. Depending on f(HFP) amorphous or semi-crystalline copolymers were obtained. f(HFP) also determines the minimum pressure required to allow for homogeneous phase reactions. For example, HFP-rich copolymerizations in 70 wt.-% CO(2) at 100 degrees C require a pressure of around 500 bar. Further, bulk copolymerizations in homogenous phase were feasible for f(HFP) 0.65 at 900 bar up to complete VDF conversion. Copolymerizations in the presence of perfluorinated hexyl iodide carried out at 75 degrees C gave access to low dispersity polymers. Due to homogeneous phase conditions the use of any surfactants or fluorinated cosolvent is avoided.
KW  - copolymerization
KW  - hexafluoropropene
KW  - phase behavior
KW  - supercritical CO(2)
KW  - vinylidene fluoride
Y1  - 2011
U6  - https://doi.org/10.1002/mren.201000031
SN  - 1862-832X
VL  - 5
IS  - 1
SP  - 8
EP  - 21
PB  - Wiley-VCH
CY  - Weinheim
ER  -