Polystyrene, macroporous, beads functionalization

Macroporous resin beads, due to their mode of preparation, consist of a macroporous internal structure and highly cross-linked areas (>5%). The latter impart the resin with rigidity, whereas the porous areas provide a large internal surface for functionalization, even in the dry state. These macroporous polystyrene-based resins are subsequently modified in various manners, which render them compatible with numerous organic solvents. Furthermore, they show high resistance toward osmotic shock, but can be brittle when not manipulated carefully. 

As with MTBE, acidic resins are the catalysts employed in the industrial practice for ETBE synthesis standard products, made from different manufacturers in the form of spherical beads (e.g., Rohm and Haas, Bayer, Purolite, Dow), have similar characteristics - a macroporous structure, polystyrene-divinylbenzene, functionalized with sulfonic groups (active sites 5.2 eq H per kg). 

Macroporous resins are compatible with organic, aqueous, protic and aprotic media. They have low swelling characteristics, making the resin ideal for use in fixed bed applications. Stratospheres and QuadraPure are widely used macroporous based resins. The QuadraPure consists of functionalized macroporous polystyrene beads (Figure 9.7). 

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