Aqueous dispersions properties of cross-linked polymers based on N-vinylcaprolactam

Abstract

Nanoparticles of cross-linked poly-N-vinylcaprolactam, stabilized by high molecular emulsifier -
hydrophobically modified polyacrylamide monohelic type in oil-in-water emulsion were synthesized.
Particle sizes of obtained water dispersion were defined by dynamic light scattering and transmition
electronic microscopy. It was found that synthesized dispersions are stable in time. Electrokinetic potential
were measured by laser Doppler microelectrophoresis method, it have negative value, which indicates on
negative charge of nanoparticle surface, caused by hydrolysis of amide groups to carboxylic. Wherein
electrokinetic potential depends on pH medium. It was established, the influence of inorganic salts
concentration on synthesized dispersions aggregative stability. It was shown, that threshold of rapid
coagulation is much higher than in polymer dispersions synthesized with low-molecular emulsifiers. It was
found that the stability factors are structure-mechanical and electrostatic barriers.