Kinetics of RAFT homopolymerisation of vinylbenzyl chloride in the presence of xanthate or trithiocarbonate

The RAFT homopolymerisation of vinylbenzyl chloride (VBC, or chloromethyl styrene CMS) in bulk and in acetonitrile initiated by α,α′-azoisobutyronitrile (AIBN) in the presence of two chain transfer agents, O-ethyl-S-(1-methyloxycarbonyl)ethyl xanthate and dibenzyl trithiocarbonate, is presented. The reactions were monitored by 1H nuclear magnetic resonance spectroscopy in the presence of 1,2-dichloroethane as the internal standard. Such a technique enabled one to assess the evolutions of log ([M]0/[M  ]) and VBC conversion vs. time that were shown to be linear. Tobolsky’s law allowed one to determine the square of the propagation rate constant to the termination rate constant, kp2/kte, of VBC, that worths about 3 × 10−3 l mol−1 s−1 at 80 °C. On the one hand, the controlled character of the polymerisation involving dibenzyl trithiocarbonate was confirmed by size exclusion chromatography. On the other hand, the molar masses of poly(VBC) polymerised in the presence of the xanthate agent decreased with monomer conversion, as already stated with the macromolecular design via interchange of xanthates (MADIX) polymerisation of styrene.

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► RAFT homopolymerisation of VBC in the presence of a xanthate and a trithiocarbonate.
► 1H NMR spectroscopy monitoring assessed log ([M]0/[M  ]) and VBC conversion vs. time.
► kp2/kte, of VBC, 3 × 10−3 l mol−1 s−1 at 80 °C, was determined by the Tobolsky’s law.
► The homopolymerisation of VBC with trithiocarbonate was controlled.