Abstract
The organometallic-mediated radical polymerization (OMRP) of vinylidene fluoride (VDF) using an alkyl cobalt(III) compound as initiator was recently proven successful for the controlled synthesis of PVDF (Angew. Chem., Int. Ed. 2018, 57, 2934–2937). However, the required synthesis of the organometallic initiator renders this method labor-intensive and time-consuming. This article reports the straightforward synthesis of well-defined poly(VDF) and its block copolymers via OMRP performed using a two-component initiating system from readily available compounds. First, PVDF was obtained by redox initiation using the combination of a peroxide initiator and bis(acetylacetonato)cobalt(II) (Co(acac)2). This step was optimized in terms of the initiator choice, polymerization temperature, and reactant molar ratio. The best results regarding the molar mass control and the dispersities were obtained using bis(tert-butylcyclohexyl) peroxydicarbonate as initiator at 60 °C. The polymerization followed first-order kinetics, and the molar masses of PVDF increased linearly up to a 27% conversion to reach 11 800 g/mol with low dispersities (Đ = 1.35). Chain extension of the resulting PVDF-Co(acac)2 with vinyl acetate (VAc) led to three diblock copolymers of various chain lengths.