The role of vinyl terminated silanes for producing highly concentrated polystyrene slurries in a single step process

Abstract

Slurries with low viscosity and polystyrene (PS) nanoparticle concentration up to 52 wt.% have been synthesized in one-step process with no waste generation, by suspension polymerization and optimizing the concentration of dispersants (sodium dodecyl sulfate, SDS, and the cosurfactant, CS). The CS was manufactured in situ from tetraethyl orthosilicate (TEOS) and vinyltriethoxysilane (VTES). The incorporation of the CS on the PS polymer was confirmed by FT-IR, EDS, and TGA, observing the functionalization of PS nanoparticles with SiOH. Morphology and particle size of the dispersed solid, together with viscosity and stability of the polystyrene slurries (PSSs), were analyzed, finding an abrupt reduction of the viscosity for PSSs by combining SDS and CS. Addition of SDS and CS (3.0 and 1.5 wt.%, respectively) allowed to produce PSSs with improved stability (ζ = − 48.5 mV after 1 year), low viscosity (20.5 mPa·s at 25 °C), and Newtonian behavior, containing up to 40.0 wt.% of single-spherical PS nanoparticles (< 100 nm).