| Abstract: | Series of polystyrene and polymethyl methacrylate latex dispersions have been prepared in the absence of any surfactant using potassium persulphate as an initiator. The latex particles are stabilised by the electrical repulsion generated by the sulphate groups which are covalently linked to the polymer molecules and are not removed by dialysis. The effects of polymerisation temperature, monomer concentration and initiator concentration on the ultimate particle size and conversion were investigated for these two series of lattices. The modal diameters of these lattices were found to be in the range of 530 to 1550 nm for polystyrene lattices, and 140 to 270 nm for polymethyl methacrylate lattices. The surface charge densities were calculated from conductometric titration results for polymethyl methacrylate lattices and were found to increase almost linearly with increase of the concentration of potassium persulphate used. |
