LI Guanghui, ZHANG Guicai, WANG Hao, et al. Preparation of cationic polyacrylamide microspheres by concentrated emulsion polymerization and its size evolution[J]. CIESC Journal, 2014, (8): 3107-3113.
DOI:
LI Guanghui, ZHANG Guicai, WANG Hao, et al. Preparation of cationic polyacrylamide microspheres by concentrated emulsion polymerization and its size evolution[J]. CIESC Journal, 2014, (8): 3107-3113.DOI: 10.3969/j.issn.0438-1157.2014.08.035.
Preparation of cationic polyacrylamide microspheres by concentrated emulsion polymerization and its size evolution
Concentrated emulsion polymerization has great potential use in oil production due to its product characteristics of high stability and proper particle size close to formation pore
which complements the gel particles synthesized by microemulsion polymerization and suspension polymerization. A series of concentrated emulsion were prepared based on microemulsion with acrylamide and methylacryloxylethyl trimethyl ammonium chloride as monomers. The structure
size distribution
stability of this emulsion before and after polymerization were determined by conductivity measurement
rheology analysis
and microscope observation. The results showed that both viscosity and yielding stress decreased with increasing monomer concentration (CM) in water phase and had a maximum value with increasing surfactant content (mS). The same trend was found for emulsion stability. The emulsion destability of CM >40% or mS =2.5 g was separately attributed to percolation effect and insufficiency emulsification in high dispersion viscosity; especially
the particle size with 1-30 mm and bimodal distribution before polymerization evolved to that with 0.4-5 mm and unimodal distribution after polymerization. This size evolution could be explained by Kolmogoro-Hinze emulsification theory
further testified by the phenomenon that the viscosity of microsphere emulsion was enhanced as much as ten times that of emulsion before polymerization.