An amphiphilic reversible addition-fragmentation chain transfer (RAFT) agent containing alkenyl vinylic bonds was synthesized by the sequential RAFT polymerization of acrylic acid and asymmetric divinyl monomer 4-((but-3-en-1-yloxy)methyl) styrene

where the pendent inert alkene bonds were embedded between hydrophilic and hydrophobic block.Styrene(St) solution polymerization and mini-emulsion polymerization mediated by the amphiphilic RAFT agent were implemented

aiming at investigating the effects of polymerization methods on the reactivity of the pendent alkene groups.During solution polymerization

the alkene groups show extremely low reactivity and remained intact in the studied St conversion range(68.6%).The resulting polymers retained quantitative alkenyl groups and had predictable molecular weights together with narrowed molecular weight distributions.These findings proved the living characters of the solution polymerization.A different case was found for RAFT mini-emulsion polymerization that copolymerization of alkenyl group with St occurred since the early stage of reaction

leading to the coupling between polymer chains or RAFT agents.As a result

experimental molecular weights positively deviated from theoretical values

and polymers had rather high polydispersity index.It was speculated that the reaction of alkenyl groups was enhanced as a result of the adsorption of amphiphilic RAFT agent onto the surface of monomer mini-droplets

since it could cause an increase in either the concentration of propagation radicals or the concentration ratio of alkene group to St in the oil-water interface layer of droplets.