Amine resins, catalyst deactivation

AmberlySt 15, properties, 44t Amine resins, catalyst deactivation, 98... 

Rollman (4 3) synthesized a series of polymer-bonded metalloporphyrins. Functionalized tetraphenyIporphyrines were attached to porous polystyrene resins via amine, carbonyl and ester linkages and metal ions (Co,Ni,Cu,Zn) were then incorporated into the structures. The porphyrin polymers that contained both oxidation (Co) and proton-acceptor sites (amine and carboxylate groups) were effective catalysts for the oxidation of thiols to disulfides. When the catalyst was exposed to a refinery stream containing only 180 ppm mercaptan sulfur, deactivation occurred. Deactivation was thought to occur via oxidation of the porphyrins by free radicals known to be present in such catalytic systems. 

Ion-exchange resins have also served as catalysts [32-35]. However, the resin gets completely deactivated at around 200°C, and the safe working temperature is around 125°C. Strongly acidic resins are prepared by sulfonation of polystyrene gels. Strongly basic resins are obtained by the amination of chloromethylated resins by tertiary amines such as trimethyl amine ... 

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