Abstract
The radical polymerization of styrene (St) initiated by a trifluoromethyl radical generated from a perfluorinated highly branched persistent radical (PPFR) is presented with an isolated yield above 70 %. The release of .CF3 radical occurred from a temperature above 85 °C. Deeper 1H and 19F NMR spectroscopies of the resulting fluorinated polystyrenes (CF3‐PSts) evidenced the presence of both CF3 end‐group of the PSt chain and the trifluoromethylation of the phenyl ring (in meta‐position mainly). [PPFR]0/[St]0 initial molar ratios of 3:1, 3:10 and 3:100 led to various molar masses ranging from 1750 to 5400 g mol−1 in 70–86 % yields. MALDI‐TOF spectrometry of such CF3‐PSts highlighted polymeric distributions which evidenced differences between m/z fragments of 104 and 172 corresponding to styrene and trifluoromethyl styrene units, respectively. Such CF3‐PSt polymers were also compared to conventional PSts produced from the radical polymerization of St initiated by a peroxydicarbonate initiator. A mechanism of the polymerization is presented showing the formation of a trifluoromethyl styrene first, followed by its radical (co)polymerization with styrene. The thermal properties (thermal stability and glass transition temperature, Tg) of these polymers were also compared and revealed a much better thermal stability of the CF3‐PSt (10 % weight loss at 356–376 °C) and a Tg of around 70 °C.