Synthesis of polymer microspheres with mercapto groups by polycondensation of α,ω-alkanedithiol and α,ω-dibromoalkane in the presence of a polystyrene latex

Polymer microspheres with mercapto groups were synthesized by the polycondensation of α,ω-alkanedithiol and α,ω-dibromoalkane in the presence of a polystyrene latex (PSt) and a nonionic surfactant. The immobilization of the mercapto group onto the microsphere was studied using dithiols with various alkylene chain lengths and PSt seed particles with different diameters. When small-sized PSt seed particles (0,40 μm) were used, the mercapto group content was high. In contrast, the use of large seed particles (0,89 μm) in the polycondensation reaction resulted in microspheres with low mercapto group content in spite of the use of an excess amount of dithiol. The polycondensation with 1,4-butanedithiol afforded microspheres with high mercapto group content. Silver ions were found to be adsorbed onto the microspheres with mercapto groups.