ma0355352_si_001.pdf (66.52 kB)
Use of a Lewis Acid Surfactant Combined Catalyst in Cationic Polymerization in Miniemulsion: Apparent and Hidden Initiators
journal contribution
posted on 2004-05-04, 00:00 authored by Virginie Touchard, Christian Graillat, Christophe Boisson, Franck D'Agosto, Roger SpitzA Lewis acid surfactant combined catalyst (LASC) was tentatively used in a cationic
polymerization in miniemulsion of p-methoxystyrene (pMOS). In a first part, the initiating potential of
trisdodecyl sulfate ytterbium (Yb(DS)3, 0.25H2O) was evidenced in the solution polymerization of pMOS
initiated by the corresponding chlorinated adduct pMOS−HCl. Miniemulsion polymerizations of pMOS
performed using the same initiating system gave rise to oligomers, but experimental conditions chosen
could not evidence the expected LASC-mediated cationic polymerization process. Further studies showed
that LASC is located at the interface and acts only as a surfactant together with SDS. The polymerization
occurred due to the hydrolysis of pMOS−HCl. The resulting acidification of the water phase leads to the
transformation of SDS into its sulfuric acid form acting as an inisurf according to an interfacial cationic
polymerization process. Latex particles of pMOS incorporating narrowly distributed low molar mass chains
were obtained.