Nonionic latices in aqueous media part 1. Preparation and characterization of polystyrene latices

Abstract

A series of non-ionic polystyrene latices in aqueous media containing particles with a narrow size distribution have been prepared using a nonyl phenol poly(ehylene glycol) condensate as the surfactant, methoxy poly(ethylene glycol methacrylate) as the comonomer/stabilizer, and ascorbic acid/hydrogen peroxide as the initiator system. As a control synthesis for comparison with the above latex, a charge stabilized polystyrene latex was prepared, using an anionic surfactant and potassium persulphate as the initiator. Latices employing a combination of charge plus steric stabilization mechanisms were also prepared, in order to investigate the effect of the non-ionic surfactant and the comonomet/stabilizer. The particle size of the latices was measured by transmission electron microscopy, the surface charge density by conductimetric titration and the glass transition temperature of the polymer by differential scanning calorimetry. The latex prepared using non-ionic ingredients, showed no titratable charge and exhibited a profound lowering of the glass transition temperature, with respect to the charge stabilized latex. On the basis of these results, schematic models for the polymerization mechanism and the morphology of the latex particles are proposed.

Graft copolymers having hydrophobic backbone and hydrophilic branches. XXIII. Particle size control of poly(ethylene glycol)-coated polystyrene nanoparticles prepared by macromonomer method

“…A range of dependence of particle size on stabilizer concentration has been found for nonaqueous dispersion polymerization. 25 In this study, the macromonomer concentration can affect the extent of the aggregation of nuclei by changing the adsorption rate of the macromonomer. Macromonomers with higher concentration (in feed) are more liable to be adsorbed onto hydrophobic nanoparticle surfaces, which will increase the particle stability sterically.…”

Synthesis of hairy acrylic core-shell particles as toughening agents for epoxy networks

“…The latter latexes usually can be produced by reaction with a macromonomer, a reactive or a polymeric surfactant. The advantage of using a macromonomer is that the hairy layer which contains the reactive group is covalently linked to the particle surface as reported by Hoshino 29) , Ottewill and Westby 30,31) using methacrylate-terminated poly(ethylene oxide) (PEO).…”

Atom Transfer Radical Dispersion Polymerization of Styrene in the Presence of PEO‐based Macromonomer

“…The reactive surfactant can be a polymer containing a polymerizable end group, such as a macromonomer (MM), which can be copolymerized with the added monomers to afford polymer particles with surfactants covalently anchored on the surface of the formed particles. [17][18][19][20] For instance, poly(ethylene oxide) (PEO)-based MM with a reactive vinyl end group could work as a reactive dispersant for the dispersion polymerization of styrene in a mixture of methanol and water, generating nearly monodisperse microspheres. [21,22] Recently, a Commercially available poly(ethylene oxide) macromonomers are successfully used as reactive stabilizers for atom transfer radical dispersion/precipitation polymerization of styrene.…”