%0 Journal Article
%A Kostjuk, Sergei V.
%A Ortega, Esteban
%A Ganachaud, François
%A Améduri, Bruno
%A Boutevin, Bernard
%D 2009
%T Anionic Ring-Opening Polymerization of Hexafluoropropylene Oxide Using Alkali Metal Fluorides as Catalysts: A Mechanistic Study
%U https://acs.figshare.com/articles/journal_contribution/Anionic_Ring_Opening_Polymerization_of_Hexafluoropropylene_Oxide_Using_Alkali_Metal_Fluorides_as_Catalysts_A_Mechanistic_Study/2879584
%R 10.1021/ma8012338.s001
%2 https://acs.figshare.com/ndownloader/files/4577458
%K molar mass polymers
%K hexafluoropropylene oxide
%K fluoride
%K 1 H NMR
%K Alkali Metal Fluorides
%K polymerization
%K KF
%K batch
%K monoadduct CF 3CF
%K masse
%K DPn
%K 4F
%X The anionic ring-opening polymerization of hexafluoropropylene oxide using the conventional alkali metal fluorides/tetraglyme catalytic system in the presence of different fluorinated solvents at various temperatures and under batch conditions is reported. Basically, the sodium fluoride (NaF)/tetraglyme system gave only monoadduct CF3CF2CO2CH3, while cesium fluoride (CsF)/tetraglyme produced oligomeric product with number-average degree of polymerization (DPn) less than 5. The higher molar mass polymers were synthesized using the potassium fluoride (KF)/tetraglyme catalytic system and 1,1,1,3,3-pentafluorobutane (C4F5H5) or 1,3-bis(trifluoromethyl)benzene as solvent at 0 °C. Under these conditions, polymers with number-average molar masses ranging between 2500 and 3500 g mol−1 were obtained in high contents (>90%) and almost without any low molar mass (DPn ≤ 5) contaminants (4−7%). Polymers which chain ends were derived into methyl esters were fully characterized by gas chromatography, 19F and 1H NMR, and MALDI-TOF-MS spectroscopy. A kinetic study allowed us to propose a tentative mechanism entailing (i) the livingness of the polymerization of the hexafluoropropylene oxide with KF/tetraglyme catalytic system and (ii) the importance on the control of molar masses of the biphasic gas/liquid environment in the batch autoclave.
%I ACS Publications