STABILIZING EFFECT OF THE CATIONIC SURFACTANT (CPB) IN EMULSION POLYMERIZATION

Stable latices were prepared from the emulsion polymerization of styre ne, using 2,2'-azobis(2-amidinopropane) dihydrochloride as the initiat or and cetylpyridinium bromide (CPB), or a mixture of CPB and a nonion ic surfactant as the emulsifier. The latices prepared with CPB exhibit s extraordinarily low surface coverage values. The outstanding stabili zing effect of CPB outweighs the mixed-surfactant effect. However, the initiation was promoted by using the mixed surfactants. Increasing th e initiator content, the initiation efficiency decreases and the kinet ic moves toward the ideal case. The hydrodynamic layer thickness of la tices have also been investigated.