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Homogeneous Phase Polymerization of Vinylidene Fluoride in Supercritical CO 2 : Surfactant Free Synthesis and Kinetics
Author(s) -
Beuermann Sabine,
Imranulhaq M.
Publication year - 2007
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200751325
Subject(s) - iodide , polymerization , supercritical carbon dioxide , supercritical fluid , polymer , polymer chemistry , chemistry , fluoride , molar mass distribution , kinetics , phase (matter) , chemical engineering , organic chemistry , inorganic chemistry , engineering , physics , quantum mechanics
Abstract Summary: Vinylidene fluoride (VDF) polymerizations were carried out in homogeneous phase with supercritical carbon dioxide (scCO 2 ) at 120 °C and 1500 bar. To control molecular weight perfluorohexyl iodide was used. Molecular weight analysis by size‐exclusion chromatography indicates that polymers of low polydispersities ranging from 1.5 to 1.2 at the highest iodide concentration of 0.25 mol · L −1 were obtained. In addition, polymer molecular weight increases linearly with reaction time, indicating that living conditions were established. The “livingness” is based on the labile C‐I bond. The weakness of the C‐I bond is associated with a fast decomposition of the original hexyl iodide, thus, contributing to initiation and to a significant increase in the initiation rate in the initial phase of the polymerization.