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Unimodal Particle Size Distribution Latexes: Effect of Reaction Conditions on Viscosity and Stability at High Solids Content
Author(s) -
Mariz Inês de F. A.,
de la Cal José C.,
Leiza Jose R.
Publication year - 2011
Publication title -
macromolecular reaction engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.37
H-Index - 32
eISSN - 1862-8338
pISSN - 1862-832X
DOI - 10.1002/mren.201100016
Subject(s) - pulmonary surfactant , emulsion polymerization , viscosity , particle size , monomer , polymer chemistry , emulsion , shear thinning , particle size distribution , polymerization , chemical engineering , particle (ecology) , chemistry , materials science , polymer , organic chemistry , composite material , oceanography , engineering , geology
The effect of process variables on the stability and viscosity of high solids content (HSC) latexes (60 wt%) with unimodal particle size distribution (PSD) (centered in 300 nm) synthesized by conventional seeded semibatch emulsion polymerization was investigated. The effect of the use of carboxylic monomers and its type, the concentration and type of surfactants and the pH of the polymerization were considered. It was found that the more stable latexes were produced under basic pH and using carboxylic monomers in the formulation. When carboxylic monomers were not used stable latexes could also be obtained, but using slightly larger concentrations of the anionic surfactant. The use of non‐ionic surfactants in combinations with anionic ones during the synthesis of the latexes was deleterious in all the cases. The viscosity of the latexes was shear thinning and latexes synthesized at basic pH and with higher concentration of surfactant presented relatively higher viscosities.