Styrene divinyl benzene copolymers. I. Texture of macroporous copolymers with ethyl-2-hexanoic acid in diluent

The texture and the pore size distribution of a set of styrene divinylbenzene copolymers, prepared by suspension polymerization with various compositions and various amounts of ethyl‐2‐hexanoic acid as diluent, have been studied using nitrogen adsorption‐desorption isotherms, mercury porosimetry, and scanning‐electron microscopy. It appears that pore volume and surface area may be well predicted in a large range of conditions (divinylbenzene contents between 20 and 60%, ethyl‐2‐hexanoic acid contents between 35% and 60%). In this range of conditions there are three structures: the elementary nuclei are spherical particles of about 100–200 Å in diameter. They are organized in microspheres of about 500–1000 Å, and the microspheres form aggregates (2500–5000 Å) more or less separated by large holes. The smaller pores (