Polymerization of acrylamide in nonionic microemulsions: Characterization of the microlatices and polymers formed

Abstract

Free radical polymerization of acrylamide was carried out in nonionic microemulsions of water, an isoparaffinic oil, Isopar M and a blend of nonionic emulsifiers: a sorbitan sesquioleate and a polyoxyethylene sorbitol hexaoleate (HLB of the mixture: 9.3). The size and the stability of the latex particles formed after polymerization were studied as a function of monomer, emulsifier and electrolyte concentration. High emulsifier and high monomer contents favor obtaining high molecular weight polyacrylamides. It is shown that both the number of polymer chains contained in each latex particle and the size of the particles are essentially controlled by the acrylamide/emulsifier weight ratio.

Effect of percolation on free‐radical polymerization of acrylamide in inverse microemulsion

“…Similar behaviour of N,, with respect to increasing concentration of acrylamide in inverse microemulsion was observed in Ref. 16. Unfortunately, no information was given16 on the percolating and/or nonpercolating behaviour of the inverse microemulsion studied.…”

Inverse micro-emulsion polymerization of acrylamide in the presence of a mixture of oleophilic/hydrophilic surfactants

“…4,6 In our preceding paper7 information was given for the preparation and viscosimetric characterization of a single-phase dispersion system arising from toluene/ AOT solutions upon addition of di †erent amounts of acrylamide solution in water (i.e. the volume fractions of the dispersed water ] acrylamide phase was grad-(' aw ), ually changed from zero to about 80% in the dispersion system) and on the polymerization behaviour of these dispersion systems.…”

RAFT Inverse Microemulsion Polymerization: Effects of Monomer Solubility and Different Types of Initiators

“…As already discussed, changes in the pH also modifies the final content of monomer in the micelles. These high and low concentration of monomer are similar scenarios to emulsion polymerizations under batch versus monomer‐starved conditions, where polymers with high and low molar mass averages are produced, respectively . This helps explain why the molar mass decreases consistently as function of the DMAEMA reversible protonation, for both nonliving and RAFT conditions.…”

“…These high and low concentration of monomer are similar scenarios to emulsion polymerizations under batch versus monomer-starved conditions, where polymers with high and low molar mass averages are produced, respectively. [22,27,52] This helps explain why the molar mass decreases consistently as function of the DMAEMA reversible protonation, for both nonliving and RAFT conditions. Moreover, M w /M n > 1.5 are normally reported for RAFT polymerization in dispersed systems, [16,25,[53][54][55][56] revealing the challenge to obtain narrow distributions in such processes.…”