Porous texture and bromine distribution in porous styrene-bromostyrene-divinylbenzene terpolymers

Abstract

The texture and the bromine distribution of styrene-bromostyrene-divinylbenzene terpolymers have been studied. These polymers were synthesized by suspension radical polymerization in the presence of porogenic agents of either macromolecular or precipitating type. The influence of DVB content on the texture (porous volume, specific area) has been found for different bromostyrene contents in the initial reaction mixture, the porogenic agent proportion remaining constant. A synthesis with a macromolecular porogenic agent led to a homogeneous bromine distribution within the support. On the other hand, when a precipitating porogenic agent was used, the formation of a peripheral halo with a higher bromine content was found. The halo thickness depended only on the concentrations of porogenic agent and of bromostyrene in the initial mixture. These results can be explained by the great hydrophilicity of the bromostyrene compared with the other “comonomers” present in the system.