Polymers as catalysts

Modification of polymers is a topic in polymer science, because new highly valued or improved applications often require sophisticated chemical structures along the polymer chains. One of such timely domains of interest comprises the development of modified polymers as catalysts for chemical processes. Of course, we do not have in mind catalysts, wherein polymers function as inert supports for the active centers and nomore. In fact, our aim is to develop polymeric catalysts, which combine advantages of the other type of catalysts, viz. 

The first section, Chemical Reactions on Polymers, deals with aspects of chemical reactions occurring on polymers—aspects relating to polymer size, shape, and composition are described in detail. One of the timely fields of applications comprises the use of modified polymers as catalysts (such as the immobilization of centers for homogeneous catalysis). This topic is considered in detail in Chapters 2, 3, 8, 9, and 11 and dealt with to a lesser extent in other chapters. The use of models and neighboring group effect(s) is described in detail. The modification of polymers for chemical and physical change is also described in detail in Chapters 2 (polystyrene) 4 (polyvinyl chloride) 5 (polyacrylic acid, polyvinyl alcohol, polyethyleneimine, and polyacrylamide) 6 (polyimides) 7 (polyvinyl alcohol) 8 (polystyrene sulfonate and polyvinylphosphonate) 10 (polyacrylamide) and 12 (organotin carboxylates). 

Soluble Polymers as Catalyst and Reagent Platforms Liquid-phase Methodologies... 

The majority of inorganic reactions can be placed into one of two broad classes (1) oxidation-reduction (redox) reactions including atom and electron transfer reactions and (2) substitution reactions. Terms such as inner sphere, outer sphere, and photo-related reactions are employed to describe redox reactions. Such reactions are important in the synthesis of polymers and monomers and in the use of metal-containing polymers as catalysts and in applications involving transfer of heat, electricity, and light. They will not be dealt with to any appreciable extent in this chapter. 

These cinchona copolymers are efficient catalysts for some asymmetric Michael reactions. Examples are shown in equations (I) and (II). In the second example, use of quinidine-acrylonitrile polymer as catalyst leads to a product with q d + 36.3° when quinidine itself is used, the ao of the product is +3.9°. The figures imply that the copolymer is more stereoselective than the monomer. 

Metal Species Supported on Organic Polymers as Catalysts for the Epoxidation of Alkenes Ulrich Arnold ... 

P. Reyes, G. Borda, J. Gnecco, B. L. Rivas, Mo02(acac)2 immobilized on polymers as catalysts for cyclohexene epoxidation Effect of the degree of crosslinking, /. Appl. Polym. Sci. 93 (2004) 1602. 

USE In antifouling compositions as emulsifier and dis -persing agent as antioxidant in lubricating oils as combustion-improver in fuel oils as stabilizer for amide polymers as catalyst. 

R. Breslow, H. Kohn, B. Siegel, Methylated cyclodextrin and a cyclodextrin polymer as catalysts in selective anisole chlorination. Tetrahedron Lett., 1976, 1645-1646. 

M.C. Lefebvre, Z. Qi, and P.G. Pickup, Electronically conducting proton exchange polymers as catalyst supports for proton exchange membrane fuel cells, J. Electrochem. Soc., 146, 2054-2058 999). 

Nitrogen-Containing Ligands Anchored onto Polymers as Catalyst Stabilizer for Catalytic Enantioselective Reactions... 

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