A series Semi-interpenetrating polymer networks(SIPN) of PU／PS polymer composites were prepared by PU／St concentrated emulsion polymerization．The effects of the dispersed phase content and polymerization temperature on polymerization kinetic and stability were studies respectively．The size and distribution of polymer latex particles

morphology of latex particles

polymer Tg and tensile strength have been determined．The powder resin of PU／PS polymer composites was obtained．The particle size and distribution of the polymer latex can he easily controlled by controlling the monomer cell size．The obtained powder polymer composites can be more easily reprocessed

so their usefulness area will be increased．