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[PDF/ePub Download] microwave assisted polymer synthesis …

A polymer-assisted solution-phase (PASP) synthesis of lead structure analogues ready for biological testing without the demand for chromatographic purification is described. Carboxylic acids are coupled to the Kenner or Ellman safety catch linker, respectively, activated by methylation or cyanomethylation and subsequently transferred to the 2′-amino group of the 2′-amino-2′-deoxyadenosine scaffold (5). The chemoselective attack of weakly nucleophilic amino groups on the N-alkylated N-acyl sulfonamide linker allows for the synthesis of amides 6 in high yields without the need for protection of primary and secondary hydroxyl functions. Thus, the use of 4-sulfamylbenzoylaminomethyl polystyrene is reported for the construction of chemoselective polymer-supported acylating reagents instead of its known use as linker in solid-phase peptide or organic synthesis. This approach is demonstrated to be well suited to obtain 2′-amido-2′-deoxyadenosine derivatives 6 in parallel format. Biological evaluation of all compounds reported revealed no improvement over known lead structures.

Synthesis and processing of biodegradable and bio-based polymers by microwave irradiation ..

In order to solve this problem, surface modification techniques are applied to improve the interaction between the nanoparticles and the polymer. In the work of Yuan [], in order to prepare the silicone rubber with high thermal conductivity, pristine and surface-modified ZnO nanoparticles containing the vinyl silane group are incorporated into the silicone rubber via a hydrosilylation reaction during the curing process. The corresponding structure, morphology and properties of the silicone rubber/ZnO (SR/ZnO) and silicone rubber/SiVi@ZnO (SR/SiVi@ZnO) nanocomposites were investigated. Yuan synthesized ZnO nanoparticles (with an average size below 10 nm) by a sol-gel procedure. Next the silicone coupling agent VTES was successfully incorporated onto the surface of the nanoparticles. The SR/SiVi@ZnO nanocomposites showed better mechanical properties and higher thermal conductivity due to the formation of a cross-linking structure with the silicone rubber matrix and better dispersion in that matrix.

(SCF)-assisted polymer modification and blend synthesis.

Synthesis of Polymeric Surfactants/Dispersants, Amphiphilic Copolymers, and their Self-Assembly Principles

AB - A polymer-assisted solution-phase (PASP) synthesis of lead structure analogues ready for biological testing without the demand for chromatographic purification is described. Carboxylic acids are coupled to the Kenner or Ellman safety catch linker, respectively, activated by methylation or cyanomethylation and subsequently transferred to the 2′-amino group of the 2′-amino-2′-deoxyadenosine scaffold (5). The chemoselective attack of weakly nucleophilic amino groups on the N-alkylated N-acyl sulfonamide linker allows for the synthesis of amides 6 in high yields without the need for protection of primary and secondary hydroxyl functions. Thus, the use of 4-sulfamylbenzoylaminomethyl polystyrene is reported for the construction of chemoselective polymer-supported acylating reagents instead of its known use as linker in solid-phase peptide or organic synthesis. This approach is demonstrated to be well suited to obtain 2′-amido-2′-deoxyadenosine derivatives 6 in parallel format. Biological evaluation of all compounds reported revealed no improvement over known lead structures.

Li [] proposed a method of preparing nanometric zinc oxide using a microemulsion which is formed when alcohol is added to an emulsion system consisting of water, oil and emulsifier, until a transparent mixture is obtained. In this case the microemulsion consists of a solution of heptane and hexanol together with a non-ionic surfactant (such as Triton X-100). The growth of nanoparticles involves the exchange of the substrates Zn(NO3)2 and NaOH between the microemulsion drops and the medium (poly(ethylene glycol)—PEG 400), and aggregation of the formed nuclei. Drops of microemulsion act as a microreactor in which the desired reaction takes place. In the synthesis of ZnO, different concentrations of PEG 400 were used (0%–50%). illustrates the process of synthesis in microemulsion and the shape of ZnO nanoparticles as proposed by the aforementioned authors.

Polymer template-assisted microemulsion synthesis of …

8 Synthesis of Polymer Nanocomposites byWater-Assisted …

Poly(methyl methacrylate) was also used as a ZnO surface modifier by Hong []. Nanoparticles of zinc oxide with a diameter of approximately 30 nm were synthesized by means of homogeneous precipitation followed by calcination. In order to introduce reactive groups onto the ZnO surface, a reaction was carried out between the hydroxyl groups and a silane coupling agent (3-methacryloxypropyltrimethoxysilane). Graft polymerization was effected by means of a reaction between the ZnO, containing silanol groups, and the monomer. Tests showed that the polymerization does not alter the crystalline structure of the ZnO nanoparticles. Their dispersion in the organic solvent can greatly improve the graft polymerization of PMMA, and further improvement can be achieved by the addition of other surfactants. Modification of ZnO nanoparticles by grafted PMMA increases the degree of lyophilicity of the inorganic surface and reduces the formation of aggregates. The work of Hong , showed that ZnO nanoparticles grafted with PMMA can increase the thermal stability of polystyrene.

Xiong [] synthesized a new nanocomposite ZnO(PEGME), in which the ZnO nanoparticles and polymer groups (PEGME—poly(ethylene glycol) methyl ether) are linked by covalent bonds. The compound was analyzed in terms of composition, structure, fluorescence and specific conductance. The tests showed that the polymer nanocomposite synthesized by means of a chemical reaction has better properties than its equivalent obtained through physical mixing. The lasting stability of the properties of ZnO(PEGME) results from the strong chemical bond between the polymer and the nanoparticles. The hybrid ZnO(PEGME) has the capability of tuning luminescence spectra and has stable ionic conductance. These properties mean that the obtained compound can be used in luminescent devices and in electronic apparatus.

ABSTRACTSupercritical carbon dioxide–assisted synthesis of poly(N-isopropylacrylamide)–ferrite nanocomposites was carried out by …
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Nanocomposites: synthesis, structure, properties and …

N2 - A polymer-assisted solution-phase (PASP) synthesis of lead structure analogues ready for biological testing without the demand for chromatographic purification is described. Carboxylic acids are coupled to the Kenner or Ellman safety catch linker, respectively, activated by methylation or cyanomethylation and subsequently transferred to the 2′-amino group of the 2′-amino-2′-deoxyadenosine scaffold (5). The chemoselective attack of weakly nucleophilic amino groups on the N-alkylated N-acyl sulfonamide linker allows for the synthesis of amides 6 in high yields without the need for protection of primary and secondary hydroxyl functions. Thus, the use of 4-sulfamylbenzoylaminomethyl polystyrene is reported for the construction of chemoselective polymer-supported acylating reagents instead of its known use as linker in solid-phase peptide or organic synthesis. This approach is demonstrated to be well suited to obtain 2′-amido-2′-deoxyadenosine derivatives 6 in parallel format. Biological evaluation of all compounds reported revealed no improvement over known lead structures.

Looking for books on Polymer Chemistry

Shim [] carried out modification of zinc oxide using poly(methyl methacrylate) (PMMA). A ZnO/PMMA composite was synthesized by means of polymerization . The majority of microspheres of the MO/polymer composite are produced by coupling of existing polymer chains with the inorganic surface or by polymerization on the phase boundary of inorganic particles. Shim , demonstrated that the stability of dispersion of ZnO in a monomer depends strongly on the nature of its surface, since this provides a precondition enabling dispersion of particles of the medium within drops of monomer and consequently their enclosure in PMMA. The most important condition in the production of the composite is the interphase compatibility between the inorganic compound and the polymer. For this purpose the surface of the inorganic system should be treated with a hydrophobic organic substance. The obtained inorganic-polymer composites form persistent microspheres and combine easily into highly processed polymers. Similar studies have been carried out and published by other researchers [,].

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Li [] also studied the photocatalytic properties of ZnO. ZnO nanospheres were obtained using an electrochemical method, in the presence of POMs (polyoxometalates), at room temperature. The experiments showed that POMs play a very important role in the formation of ZnO nanospheres. The photocatalytic properties of ZnO were determined using the example of degradation of rhodamine (RhB). Based on this study Li , concluded that ZnO displays high photocatalytic activity below the UV range. The proposed simple, single-stage method of synthesis makes it possible to obtain spherical ZnO particles and provides the possibility of controlling their shape.

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