Polymeric organic components

Organic-inorganic redox pairs initiate polymerization, usually but not always by oxidation of the organic component, for example, the oxidation of an alcohol by Ce4+,... 

Ethylene is also employed as an olefmic component of the Mizoroki-Heck polymerization. Organic dihalides thus couple with ethylene in the presence of a palladium catalyst to afford PAV-type polymers 161 and 162, as shown in Equations (77) and (78). ... 

Although atmospheric contamination of the polymer is generally minimal, it can be extensive because the dry polymer has a high affinity and capacity for almost all organic components. This situation is one of the reasons why the cleaned polymers are stored under an organic solvent such as methanol (78). With proper storage, the atmospheric contamination can be maintained well below interference levels. This situation is not the case for impurities from the polymerization process. 

In their original discovery of miniemulsion polymerization, Ugelstad and co-workers [5] used either cetyl alcohol (CA water solubility estimated at 6x10 [43]) or hexadecane (HD water solubihty estimated at 1x10 [43]) to retard monomer diffusion from submicron monomer droplets. Both CA and HD, referred to here as costabilizers, are volatile organic components and are therefore not entirely desirable in the final product. Other researchers have used polymers, chain transfer agents, and comonomers as stabiUzers, as will be discussed later. 

Recent developments in the cross-polymerization of the organic components used in bicontinuous microemulsions ensure the successful formation of transparent nanostruc-tured materials. Current research into using polymerizable bicontinuous microemulsions as a one-pot process for producing functional membranes and inorganic/polymer nanocomposites is highlighted with examples. 

This type of cross-polymerization of all of the organic components (hke MMA, HEMA and a polymerizable surfactant) in a bicontinuous microemulsion is an important area of recent development in microemulsion polymerization, which can be used to produce nanostructures of transparent polymer solids. The polymerization can be readily initiated using either redox or photo-initiators. The gel formation usually occurred within 20 minutes. The use of this novel type of microemulsion polymerization for preparing transparent inorganic-polymer nanocomposites in the form of films or sheets is emerging and exciting. However, very little pubhshed information about this type of nanocomposite is available, as will be described in the following sections. 

Extractables from filter membranes can be classified into two groups, inorganic ions and organic molecules. The organic components are residual components from either the polymerization process or a chemical modification step. Filters are deliberately washed to remove these components, and the extent to which they remain in the membranes is... 

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