Abstract
The polymerization of styrene in three-component oil-in-water microemulsions made with the cationic surfactant dodecyltrimethylammonium bromide is studied by dilatometry and quasielastic light scattering as a function of type and concentration of initiator. Fast polymerization rates, high conversions, and high molecular weight polymers are achieved with both oil-soluble (AIBN) and water-soluble (potassium persulfate) initiators. The rate of polymerization shows initiation and termination intervals, but no constant-rate interval is observed. Stable monodisperse microlatexes are obtained with both types of initiators. For both AIBN and potassium persulfate, polystyrene molecular weight is proportional to initiator concentration [I]-0.4 and particle radii decrease as [I]-0.2. Polymerization initiation occurs in or at the microemulsion droplets, and polymer particles grow by recruiting monomer and surfactant from uninitiated swollen micelles.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 114-123 |
| Number of pages | 10 |
| Journal | Colloid & Polymer Science |
| Volume | 271 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 1993 |
Keywords
- Styrene polymerization
- latex
- microemulsion
- polystyrene