Reactive surfactants in styrene microemulsion polymerization

Polymerization of styrene has been carried out in microemulsion using the sodium salt of the maleic dodecyl hemiester as surfactant and hydroxypropyl methacrylate as cosurfactant. In a limited range of composition, this system forms a transparent microemulsion, leading to small particles ranging between from 15 to 30 nm of diameter. The stability of the system is dependent upon the ionic strength of the media. A model explaining how the limits in solid contents are dependent on the ionic strength is proposed. Fast polymerization with formation of very high molecular weight chains occurs. The cosurfactant is well copolymerized with the styrene, but the surfactant is shown to be only partially incorporated.