JV-Vinyl-2-pyrrolidone

In conclusion, the order of reduction of metal ions is controlled by their redox potential. This is also true in other pairs of precious metals such as Pd/Pt, Au/Pd, etc. (53). In addition, poly(jV-vinyl-2-pyrrolidone) (PVP) plays an important role for the formation of the core/shell structure. In the case of the Au/Pt system, the aggregation starts from Au but not Pt. This is probably due to the coordinating ability of metals to PVP. The Pt atoms or microclusters coordinating to PVP are more stable than the Au atoms or microclusters, since Au cannot coordinate to PVP. Thus, Au atoms or microcluster aggregate at first after the reduction, and then Pt atoms or microclusters deposit on the Au nuclei. In summary, the core/shell structure is controlled by (1) the redox potential of metal ions, and (2) the coordination ability of metals to PVP, stabilizing polymer. 

PAN has a solubility parameter of about 11 H and is soluble only in polar solvents, such as dimethylacetamide (DMAc). Because of PAN s high polarity, its fibers are difficult to dye. This difficulty has been overcome by producing copolymers of acrylonitrile with small amounts (4%) of more-hydrophilic monomers, such as jV-vinyl-2-pyrrolidone (left), methacrylic acid (center), or 2-vinylpyridine (right), which have the following structures ... 

Fig. 6. Hypothesis concerning the course of the reaction during the treatment of pentacarbonyl[methoxy(phenyl)carbene]chromium(0) with JV-vinyl-2-pyrrolidones under a CO pressure of 150 atm.

Gulden, G. and Rzayev, Z. M. O. 2008. Synthesis and characterization of copolymers of JV-vinyl-2-pyrrolidone with isostructural analogs of maleic anhydride. 

A novel polyfunctional initiator has been prepared by the reaction of a copolymer of styrene and methyl methacrylate with polytetrafluoroethylene (PTFE) radicals generated photochemically from the monomer and manganese carbonyl. These radicals react with aromatic rings by addition and substitution so that the product copolymer from this reaction carries short PTFE chains with Mn(CO)6 end groups of, for example, structures (12). At 100 °C, scission of the CFj— Mn(CO)s bonds occurs with formation of active radicals, and the copolymer behaves as a polyfunctional macroinitiator. On heating this material with styrene or JV-vinyl-2-pyrrolidone a network structure and a graft copolymer respectively are formed. 

Nonequimolar JV-vinyl-2-pyrrolidone-MA copolymers have had some study. The copolymers are generally prepared in the same manner as the homopolymers of the A-vinyl lactams and have similar properties with respect to water solubility. A copolymer containing 80% by weight of MA is a useful coating for water-dispersible particulate organic polymers. Such coated polymers have enhanced dispersibility in aqueous solutions with a minimum of agglomeration of the water-soluble polymer. " ... 

Poly(JV-vinyl-2-pyrrolidone) (PVP) is available in various molecular weights (10,000, 40,000, 160,000 and 360,000, BASF and GAF Corporation) and can yield solutions of varying viscosities. PVP is best known for its unusual complexing ability toward many types of small molecule and for its physiological inertness [14]. As a thickener, it is used in biomedical, pharmaceutical, cosmetic, and personal care products (hair styling gels, shaving creams, shampoos, emollient creams and lotions, etc.). 

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