Acrylamide and Butyl Acrylate Polymerization in Winsor IV (w/o) and Winsor I (o/w) Microemulsions

Abstract

The preparation of toluene-based single-phase Winsor IV water-in-oil (w/o) inverse microemulsions containing the (co)monomer couple acrylamide (AAm)/butyl acrylate (BA), their transformation to the two-phase Winsor I (oil-in-water (o/w) microemulsion phase + excess of oil phase) microemulsion and homo-and (co)polymerization of (co)monomers initiated by ammonium peroxodisulfate in both types of microemulsions were studied. Increasing of the volume fraction of aqueous phase, Φ aw, of the parent single-phase Winsor IV w/o inverse microemulsion by addition of solution of AAm in water led first only to the increase of AAm monomer concentration in inverse microemulsion, and finally to the formation of a two-phase Winsor I o/w microemulsion. Thus, Winsor IV and Winsor I microemulsions characterized with 3-fold and 6-fold higher content of AAm (i.e., up to 6 mass % in Winsor IV and 12 mass % in the microemulsion phase of Winsor I with respect to only 2 mass % in the parent Winsor IV w/o microemulsion) were obtained. Maximum rate of (co)polymerization of AAm/BA couple in Winsor IV w/o inverse microemulsion is only 1.5 times greater than that found for o/w microemulsion phase of Winsor I. Maximum homopolymerization rate of BA in toluene-based Winsor IV inverse w/o microemulsion in comparison to BA-based Winsor IV inverse w/o inverse microemulsion is only 1/75 of the maximum rate of BA homopolymerization in the latter system. The kinetic behavior of AAm and BA (co)monomer pair in free-radical polymerization in studied microemulsions was explained as a result of the different monomer partition between water and oil phases of the dispersion system, of the capability of monomer and/or oligomer radical formation in the individual phases, and of the transfer of these radicals between individual phases of the w/o and/or o/w microemulsions.

In situ micro/nano-hydrogel synthesis from acrylamide derivates with lecithin organogel system

“…It is well known that a good bio-delivery system should provide resistance to premature enzymatic degradation and aggregation, be able to target specific tissues, transfect the cell membrane, facilitate the nuclear uptake, and supply controlled release of the genetic material, while inducing no toxicity or immune response [48,49]. For these reasons, suitable coating of delivery systems is very important for their biomedical applications [41].…”

Polymerization of vinyl monomers in separated Winsor II (w/o) and Winsor I (o/w) microemulsion phases. Part 1: preparation and characterization of polymerizable vinyl-monomer-containing microemulsions

“…It should be noted that in this case (using TB or TD titrating systems) the content of watersoluble monomer (e.g., acrylamide) can be reasonably increased in the disperse system, too. This is of some advantage for free-radical polymerization of acrylamide and preparation of polyacrylamide containing dispersions with increased polyacrylamide content [7,14,15]. Appearance of the dispersion system during titrations as a function of the volume fraction of aqueous phase, aw , temperature = 20 • C. For composition of inverse microemulsions and of titrating system see Table 1.…”

Inverse microemulsion copolymerization of butyl acrylate and acrylamide: kinetics, colloidal parameters and some model applications

“…Barton and co‐workers investigated how to obtain stable inverse microemulsions (compositional effects, polymerization and copolymerization processes, etc.) in detail 12–16…”