May Trifluoromethylation and Polymerization of Styrene Occur from a Perfluorinated Persistent Radical (PPFR)?

Abstract

The radical polymerization of styrene(St) initiated by at rifluoromethyl radicalg enerated from ap erfluorinated highly branched persistentr adical (PPFR) is presented with an isolated yield above7 0%.T he releaseo fCCF 3 radical occurred from at emperature above 85 8C. Deeper 1 Ha nd 19 FNMR spectroscopieso ft he resultingf luorinated polystyrenes (CF 3-PSts)e videnced the presence of both CF 3 endgroup of the PSt chain and the trifluoromethylation of the phenylr ing (in meta-positionm ainly).[ PPFR] 0 /[St] 0 initial molar ratios of 3:1, 3:10 and 3:100 led to variousm olar massesr anging from 1750t o5 400 gmol À1 in 70-86 %y ields. MALDI-TOF spectrometry of such CF 3-PSts highlighted polymeric distributions which evidenced differences between m/z fragments of 104 and 172 corresponding to styrene and trifluoromethyl styreneu nits,r espectively.S uch CF 3-PSt polymers werea lso compared to conventional PSts produced from the radical polymerization of St initiatedb yaperoxydicarbonate initiator.Amechanism of the polymerization is presented showing the formation of at rifluoromethyl styrene first, followed by its radical (co)polymerization with styrene. The thermal properties (thermals tability and glass transition temperature, T g)o ft hesep olymers were also compared and revealed am uch better thermals tabilityo ft he CF 3-PSt (10 %w eight loss at 356-376 8C) and a T g of around 70 8C.

Liquid-Assisted Grinding Enables a Direct Mechanochemical Functionalization of Polystyrene Waste

“…-62.1 ppm) which is consistent with analytical data from prior reports of radical PS trifluoromethylations (Figures S58-S65). [19][20][21]63 To determine the optimal mechanochemical parameters needed for lower molar mass PS functionalization, we varied the size of the milling jar, size and number of milling balls, and reaction scale for an optimized charge ratio (Table 1). The highest density of trifluoromethylation resulted from the mechanochemical parameters optimized on BB (Table 1, Entires 1 and 2).…”

Liquid-assisted grinding enables a direct mechanochemical functionalization of polystyrene waste

“…S58-S65 †). [19][20][21]63 To determine the optimal mechanochemical parameters needed for lower molar mass PS functionalization, we varied the size of the milling jar, size and number of milling balls, and reaction scale for an optimized charge ratio (Table 1). The highest density of triuoromethylation resulted from the mechanochemical parameters optimized on BB (Table 1, entires 1 and 2).…”

Liquid-Assisted Grinding Enables a Direct Mechanochemical Functionalization of Polystyrene Waste

“…-62.1 ppm) which is consistent with analytical data from prior reports of radical PS trifluoromethylations (Figures S30-34). [18][19][20]61] To determine the optimal mechanochemical parameters needed for lower molar mass PS functionalization, we varied the size of the milling jar, size and number of milling balls, and reaction scale for an optimized charge ratio (Table 1). The highest density of trifluoromethylation resulted from the mechanochemical parameters optimized on BB (Table 1, Entires 1 and 2).…”