Catalytic polymerization of ethylene in aqueous media

The kinetics of the polymerization of ethylene in aqueous media using a monometallic palladium catalyst containing phosphine ligands was investigated. The catalyst activity was lower than that in toluene and was strongly affected by both the catalyst exposure to water and type of surfactant used. Anionic surfactants may poison of the catalyst, but exposure to water was the main cause of loss of activity. The deactivation of the catalyst by water seemed to occur either before starting the reaction (namely, during the miniemulsification process) or immediately after the catalyst became in contact with ethylene. The molecular weights were not affected by the accessibility of water to the catalyst. A polymerization mechanism was proposed and a mathematical model for the process was developed.