Dispersion Stability of Pigments in Aqueous Solution of Anionic Oligo-Type Surfactants(IV);Dispersiveness of α-sulfo fatty acid vinyl ester oligomers
The sodium α-sulfo fatty acid vinyl ester oligomers, which are oligomer type surfactants were prepared by polymerization with fatty acid vinyl acetate. The α-sulfonation of fatty acid vinyl ester oligomers were carried by direct addition of sulfur trioxide. The dispersing performance of oligomer type anionic surfactants and sodium dodecyl sulfate(SDS) in the aqueous suspension of iron oxide and titanium dioxide particles was evaluated by particle size distribution and zeta-potential measurement. As results, the particles of iron oxide and titanium dioxide were flocculated by addition of small amount of oligomer type anionic surfactants and sodium dodecyl sulfate(SDS), then the flocks redispersed by more addition of oligomer type anionic surfactants and SDS. The flocculation, redispersion process was observed in lower concentration range of oligomer type anionic surfactants than SDS. Especially, the dispersing action of sodium α-sulfo palmitic acid vinyl ester oligomer was better than sodium α-sulfo lauric acid vinyl ester oligomer.