Acrylic acid Catalytic active sites

Gel-immobilized catalytic systems (GCS) represent swelled polymer composites in which active sites of the particular metal complex are inunobilized. Graft copolymers of ethylene-propylene rubber (EPRu) and ligands of 4-vinylpyridine, acrylic acid, vinylpyrrolidone, organophosphorus compounds etc. act as a polymeric supports (polymeric phases) [140]. The structure of metal complex sites immobilized in a polymer gel is presented by the following scheme ... 

Polyacrylic elastomer is a chemically saturated polymer of acrylic acid esters. Since esters are rather inert, other groups such as epoxy, halogen and carboxyl must be incorporated into the polymer to introduce sites for curing. We have studied the effect of various ammonium and phosphonium salt catalysts on the rate of crosslinking of polyacrylic elastomers which contain carboxyl and epoxy groups as cure-sites. We find that the catalytic activity of onium salts correlates with nucleophilicity of their anions. 

Ml phase " represents the clearest example of a multifunctional catalyst in which each element, in close geometrical and electronic synergy with the surrounding elements, plays a specific role in turn, as an isolated active site, in every reaction step for the alkane transformation into the partial oxidation product desired. The flexibility of the structure allows modification of the catalyst composition and hence its catalytic behavior. Moreover, this type of mixed-metal oxide catalyst has the ability to catalyze other different oxidation reactions starting from alkanes, such as propane oxidation to acrylic acid, " oxidative dehydrogenation of ethane to ethylene, and n-butane selective oxidation. ... 

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