Homogeneous Phase Polymerization of Vinylidene Fluoride in Supercritical CO₂: Surfactant Free Synthesis and Kinetics

• Published in: Macromolecular symposia Vol. 259; no. 1; pp. 210 - 217
• Main Authors: Beuermann, Sabine, Imran-ul-haq, M
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Weinheim Wiley-VCH Verlag 01-12-2007; WILEY-VCH Verlag; WILEY‐VCH Verlag; Wiley
• Subjects: Applied sciences; Bonding; Bonding strength; Carbon dioxide; Chromatography; Exact sciences and technology; Iodides; living radical polymerisation; Molecular weight; Organic polymers; Physicochemistry of polymers; Polymerization; polymerization kinetics; Preparation, kinetics, thermodynamics, mechanism and catalysts; supercritical CO2; Vinylidene fluoride; Carbon dioxide; Living polymer; Polymerization under pressure; Experimental study; Chemical reaction kinetics; Solution polymerization; Homogeneous reaction; Free radical polymerization; Chain transfer; Preparation; Vinylidene fluoride polymer; Supercritical solvent; Iodocarbon
• ISBN: 9783527323562; 3527323562
• ISSN: 1022-1360; 1521-3900
• DOI: 10.1002/masy.200751325

Vinylidene fluoride (VDF) polymerizations were carried out in homogeneous phase with supercritical carbon dioxide (scCO₂) 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.