Hydrocarbon resins Hydroxylated polymers

Next to ion exchange resins, the polymeric supports most likely to be used for catalysts are other cross-linked polystyrenes or silica gels. Both are inexpensive, easy to functionalize, and void of other reactive functional groups. Their limitations are the thermal and physical stability of polystyrene and the solubility of silica in alkali. Polystyrene can be derivatized by almost every known reaction of mononuclear aromatic hydrocarbons, and the conditions for those reactions on polymers have been published and reviewed (2D- The surface of silica gel can be covered with a wide range of organic materials by reaction of its hydroxyl groups with silyl esters and chlorosilanes f381. 

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