NONIONIC LATTICES IN AQUEOUS-MEDIA .2. STABILITY TO ADDED ELECTROLYTES

Nonionic latices in aqueous media prepared using methoxy polyethylene glycol methacrylate as a comonomer/stabiliser and ascorbic acid/hydrogen peroxide as the initiator have been examined for stability in the presence of the 2:1 electrolyte, barium chloride. These latices were found to be stable up to the concentrations of barium chloride examined, 0. 75 mol dm** minus **3. Charge stabilised latices, on the other hand, were coagulated in 2. 1 multiplied by 10** minus **2 mol dm** minus **3 barium chloride. The high stability of the nonionic latices was attributed to the grafting, during polymerisation, of methoxy polyethylene glycol chains to the surface of the core particle of polystyrene. The nonionic latices on concentration to high volume fraction gave highly ordered packing of the particles even in the presence of 0. 1 mol dm** minus **3 sodium chloride.