Miniemulsion Copolymerization of Ethylene and Vinyl Acetate

Abstract

The copolymerizations of a gaseous monomer (ethylene) and a liquid monomer (vinyl acetate) via emulsion and miniemulsion polymerizations are reported. Reactions in which the vinyl acetate was introduced in both batch and semibatch modes are carried out. (Ethylene introduction is always in a semibatch model since the polymerization is carried out under a constant pressure of ethylene in the reactor headspace.) The results are compared, drawing the conclusion that miniemulsion copolymerization has an advantage over conventional emulsion polymerization for monomers with very low water solubility (including gaseous monomers) due to their nucleation in monomer droplets without transport through the aqueous phase.

Kinetics of MMA and VAc Miniemulsion Polymerizations Using Miglyol and Castor Oil as Hydrophobe and Liquid Core

“…Therefore, in addition to the chain transfer reactions to the costabilizer, in the reactions with castor oil radicals could also react with the double bonds of the ricinoleic acid resulting in radicals with low reactivity, leading to even slower kinetics. This same behavior has already been observed for miniemulsion copolymerization of MMA and butyl acrylate in the presence of li- noleic acid and sunflower seed oil [18], linseed oil-modified polyurethane [19], or alkyd resin [20]. Molar mass distributions of polymerization R3, MMA with castor oil as costabilizer (see Fig.…”

“…In addition, slower kinetics was also shown to occur in miniemulsion copolymerizations of MMA and butyl acrylate in the presence of linoleic acid and sunflower seed oil [18], linseed oil-modified polyurethane [19], or alkyd resin [20] and was attributed to the chain transfer to those components and/or to reactions with the double bonds present in those components, both resulting in radicals with a lower reactivity.…”

Cross-Linked Network Development in Compatibilized Alkyd/Acrylic Hybrid Latex Films for the Creation of Hard Coatings

“…Data were collected with an initial increment of 10 min. for the first two hours, when most of the water is 12 being lost. Then an increment of two hours was applied for the period up to 74 h, during which the signal loss is attributed to the effects of crosslinking.…”

High Molecular Weight Copolymer Alkaline Fuel Cell Membrane via Miniemulsion Polymerization

“…Miniemulsion polymerization can yield higher conversion of monomers than that of conventional solution polymerization and those monomer droplets are like micro-reactors where the monomers are contained with the polymerization sites. Therefore, much higher molecular weight of QPMBV could be obtained (7).…”