Polymer semi-synthesis

Recently, the semi-synthesis of Vancomycin (48) on solid supports was accomplished using an allylic linker (Scheme 3.2) [123, 124]. Polymer-bound chiral electrophilic selenium reagents have been developed and applied to stereoselective se-lenylation reactions of various alkenes (Tab. 3.9) [125]. 

SEMI-SYNTHESIS IN ANTIBIOTIC, POLYMER AND PEPTIDE CHEMISTRY... 

Dihydric phenolic lipids of the cardol type are the most abundant in plant, fungal and bacterial kingdoms. The first species in which the members of the title subclass of phenolic lipids, resorcinolic lipids, were found was Ginkgo biloba (Ginkgoaceae) [6,9,10,17]. Later, the presence of resorcinolic lipids (5-n-alk(en)ylresorcinols) was shown also in other species, first, in the Anacardiaceae [14], which is an important source of various phenolic lipids, not only of alkylresorcinols but also of alkylphenols and alkylcatechols. For example, the cashew and the processing of cashew nuts are the main source of phenolic lipids for the formaldehyde-polymer industry. Aspects of Anacardium occidentale in relation to synthesis, semi-synthesis and chemical industry have been reviewed Tyman [1,11,14] as well as a recent book [2]. 

The most promising applications of template polymerization seems to be the production of materials in which the daughter polymer and the template together form a final product, because the synthesis of polymers requiring further separation of the product from the template is not acceptable for industry. The template process can be applied in order to produce a set of new materials on the basis of ladder-type polymers, semi-adder copolymers, the properties of which are not yet well known. 

Another very important class of IPNs are semi-IPNs, namely, systems in which one of the components is a linear polymer. Semi-IPNs may be characterized as sequential or simultaneous IPNs depending on the way the linear polymer is introduced. It may play the role of the host polymer for the synthesis of sequential IPNs, or that of the guest polymer for the same sequential IPNs when introduced into the system by the swelling of a network in monomers forming a linear polymer. Semi-IPNs may also be obtained by a simultaneous method via mixing the initial components of the network with linear polymer and then curing the system. Semi-IPNs may be of two types depending on what polymer is formed first linear or cross-linked. 

Davis, P. A. Nicolais, L., Ambrosio, L., and Huang, S. J., Synthesis and characterization of semi-interpenetrating polymer networks of poly(2-hydroxyethyl methacrylate) and poly(capro-lactone), Polym. Mater. Sci. Eng., 56, 536-540, 1987. 

The true value of the chloropolymer (I) lies in its use as an intermediate for the synthesis of a wide variety of polytorgano-phosphazenes) as shown in Figure 1. The nature and size of the substituent attached to the phosphorus plays a dominant roll in determining the properties of the polyphosphazene. Homopolymers prepared from I, in which the R groups are the same or, if different, similar in molecular size, tend to be semi-crystalline thermoplastics. If two or more different substituents are introduced, the resulting polymers are generally amorphous elastomers. (See Figure 1.)... 

Gel electrophoresis is widely used in the routine analysis and separation of many well-known biopolymers such as proteins or nucleic acids. Little has been reported concerning the use of this methodology for the analysis of synthetic polymers, undoubtedly since in many cases these polymers are not soluble in aqueous solution - a medium normally used for electrophoresis. Even for those water-soluble synthetic polymers, the broad molecular weight dispersities usually associated with traditional polymers generally preclude the use of electrophoretic methods. Dendrimers, however, especially those constructed using semi-controlled or controlled structure synthesis (Chapters 8 and 9), possess narrow molecular weight distribution and those that are sufficiently water solubile, usually are ideal analytes for electrophoretic methods. More specifically, poly(amidoamine) (PAMAM) and related dendrimers have been proven amendable to gel electrophoresis, as will be discussed in this chapter. 

Uses Copolymerized with methyl acrylate, methyl methacrylate, vinyl acetate, vinyl chloride, or 1,1-dichloroethylene to produce acrylic and modacrylic fibers and high-strength fibers ABS (acrylonitrile-butadiene-styrene) and acrylonitrile-styrene copolymers nitrile rubber cyano-ethylation of cotton synthetic soil block (acrylonitrile polymerized in wood pulp) manufacture of adhesives organic synthesis grain fumigant pesticide monomer for a semi-conductive polymer that can be used similar to inorganic oxide catalysts in dehydrogenation of tert-butyl alcohol to isobutylene and water pharmaceuticals antioxidants dyes and surfactants. 

This paper reviews recent developments in the synthesis of telechelic and semi-telechelic polymers via anionic methods. 

Semi-interpenetrating Polymer Network (Semi-IPN) Synthesis ... 

At the present time, polysiloxanes are unique among inorganic and semi-inorganic polymers. They have been the most studied by far, and are the most important with regard to commercial applications. Thus, it is not surprising that a large number of review articles exist describing the synthesis, properties, and applications of these materials.1 55... 

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