Polystyrene resins with immobilized enzyme

Acidic resins can be used as heterogeneous catalysts for in situ peracid formation. Protonic ion-exchange resins based on sulfonated polystyrene were used for epoxidations [119]. Acetic acid was, thus, used successfully as epoxidation catalyst in combination with resins such as Dowex 50W-X8 [104,120,121], Dowex 50X-12 [95], or Amberlite IR-120 [118,122] to epoxidize PBD. The formation of products from side reactions of the epoxides are to be expected and in some cases have been reported [122]. A more advanced approach uses the immobilized enzyme Novozym 435 to catalyze the in situ formation of peracetic acid from acetic acid and hydrogen peroxide [123]. 

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