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  • 1
    Electronic Resource
    Electronic Resource
    Kinetic Study of the "Living" Cationic Polymerization of Cyclohexyl Vinyl Ether Initiated by Hydrogen Iodide in the Presence of Ammonium Salts (1994)
    s.l. : American Chemical Society
    Macromolecules 27 (1994), S. 1401-1406 
    Details
    ISSN: 1520-5835
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ma00084a019
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  • 2
    Electronic Resource
    Electronic Resource
    End-functionalization of polystyryl and polybutadienyl lithium by chloroalkyl derivatives bearing oxygen atoms (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Polymer International 41 (1996), S. 453-462 
    Details
    ISSN: 0959-8103
    Keywords: anionic polymerization ; functionalization ; polystyryl lithium ; polybutadienyl lithium ; chain-end polystyrene ; characterization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The transformation of living polymer chain-ends is particularly well-suited to synthesize end-functionalized polymers. Herein, the development of a recent synthetic methodology is reported. High degrees of functionalization are obtained using alkyl chlorides bearing heteroatoms as functionalization agents. A mechanism involving complexation of the lithium counterion by the heteroatom of the reagent is proposed, based on the role of the heteroatom, the chloroalkyl derivative structure, and data reported in recent publications. Thus, ω-functional polymers have been prepared by reacting the corresponding living anionic polymers with a chloroacetal, a chloroether and a dichloroether. The products have been characterized by size-exclusion chromatography, 1H nuclear magnetic resonance (NMR) and 13C NMR. The degree of functionalization has been determined by 1H NMR.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    The α-halogeno ether function: formation and use in the design of tailor-made polymers (1994)
    New York, NY : Wiley-Blackwell
    Polymers for Advanced Technologies 5 (1994), S. 568-574 
    Details
    ISSN: 1042-7147
    Keywords: Preparation and reactivity of α-halogeno ether ; Initiator and macroinitiator ; Living cationic polymerization ; Vinyl ethers ; Block copolymers ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: α-Halogeno ether species, in appropriate conditions, can induce the “living” cationic polymerization of vinyl ethers. They can also be used as initiators for the “living” polymerization of styrene derivatives. Therefore, their use as intermediates in the preparation of tailor-made polymers and copolymers offers interesting opportunities in macromolecular synthesis. The main parameters which determine and control their reactivity are reviewed and discussed. The possibility to generate quantitatively these derivatives by various routes and from different organic functions such as aldehyde, ketone, acetal and hydroxyl is examined. Some of these routes have been used to generate the α-halogeno ether function directly at the end of acetal and hydroxy-terminated polymers. The latter have then been used as macroinitiators to prepare new block copolymers. The synthesis of poly(isobutyl vinyl ether-β-ethyl vinyl ether), poly(styrene-β-chloroethyl vinyl ether) and poly(chloroethyl vinyl ether-β-butadiene-β-chloroethyl vinyl ether) by this technique is described.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pat.1994.220050916
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  • 4
    Electronic Resource
    Electronic Resource
    Nature and concentration of active species in cationic polymerization of vinyl ethers: A kinetic investigation (1995)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 8 (1995), S. 293-300 
    Details
    ISSN: 0894-3230
    Keywords: Organic Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The Kinetics of the polymerization of isopropyl vinyl ether, isobutyl vinyl ether (IBVE) and chloroethyl vinyl ether initiated by HI in CH2Cl2, in the presence and in the absence of tetrabutylammonium iodide as common anion salt, were investigated. The polymerizations proceed directly through the carbon-iodide termini without any necessary electrophilic activator. As previously observed with cyclohexyl vinyl ether, it was found that the addition of small amounts of salt, (0·5-10% with respect to initial [HI], depending on the monomer) drastically reduces the polymerization rate and leads to living-type polymerizations. Higher amounts of salt have no influence on the polymerization rate which remains constant over a broad range of [NBu4I]/[HI] ratios. This general behaviour, observed for the all vinyl ethers, suggests a common ion salt effect and therefore an ionic polymerization mechanism involving ion pairs and free ions. In the absence of salt, both ion pairs and free ions of higher reactivity participate in the propagation, whereas only ion pairs contribute to the propagation in the presence of a common ion salt. According to this scheme, the living character of the polymerization is assumed to result from a propagation reaction governed by undissociated ionic species. The validity and the implications of this reaction scheme, in terms of active centre concentrations, are also discussed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/poc.610080412
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  • 5
    Electronic Resource
    Electronic Resource
    Derivatization of hydroxyl into α-chloro ether: application to the synthesis of block copolymers from hydroxy-telechelic polymers (1992)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 193 (1992), S. 2793-2806 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: It has been recently shown that a-halogeno ether, when activated by a weak Lewis acid such as ZnX2, may be used as initiator for the living cationic polymerization of vinyl ethers. A route to the a-halogeno ether function is the action of dry hydrogen halide on an alcohol in the presence of an aldehyde or a cyclic acetal. The quantitative preparation of α-chloro ethers by this route, as well as the use of such compounds to initiate the “living” cationic polymerization of vinyl ethers, was examined. This procedure was then applied to hydroxy-telechelic polybutadiene to give a macro-initiator with α-chloro ether terminal groups. The latter was used to initiate the polymerization of vinyl ethers. The synthesis of poly(butadiene-block-ethyl vinyl ether) and poly(butadiene-block-2-chloroethyl vinyl ether) is reported, as well as the preparation of other copolymers by chemical modification of the chloroethyl vinyl ether units.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1992.021931108
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  • 6
    Electronic Resource
    Electronic Resource
    Linear non-conjugated dienes from biomass as termonomers in EPDM synthesis, 1. Study of their reactivity in homo-, co- and terpolymerizations (1995)
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 196 (1995), S. 3091-3105 
    Details
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: This paper deals with the use of 3,7-dimethylocta-1,6-diene (3,7-DMO) and 5,7-dimethylocta-1,6-diene (5,7-DMO), issued from terpene feedstock, as termonomers for the synthesis of ethylene-propylene-diene terpolymers (EPDM). Their reactivity is first compared to 7-methylocta-1,6-diene (MOCD), an industrial linear diene, in homopolymerization and cross-copolymerization. Two catalytic systems are used: TiCl3, 1/3AlCl3, 14 MgCl2 associated with Al(C2H5)3, and VOCl3 or VCl4 associated with Al(C2H5)2Cl. The influence of the diene structure on the observed order of reactivity is discussed. In a second part, the copolymerization and the terpolymerization of the different dienes with ethylene and propene are implemented. A drastic influence of the diene structure and concentration on the productivity (and activity) is observed. Potentiometric titrations of the vanadium, performed both in the absence and in the presence of dienes (and of other substituted olefins), indicate that the productivity loss mainly results from a reduction process of the vanadium, involving the di- or trisubstituted olefins
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1995.021961002
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  • 7
    Electronic Resource
    Electronic Resource
    Amphiphilic block copolymers of controlled dimensions with hydrophilic glycosidic vinyl ether moieties (1998)
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 199 (1998), S. 335-342 
    Details
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: New amphiphilic diblock copolymers of controlled dimensions constituted of styrene and hydrophilic glycosidic vinyl ether moieties were prepared and their emulsifying properties examined. The hydrophobic block was obtained by living anionic polymerization of styrene, followed by a quantitative functional termination with chloroacetal derivatives. The polystyrene chain ends were then derivatized, by addition of trimethylsilyl iodide, into α-iodo ether macro-initiators. The latter were used to initiate the “living” cationic polymerization of protected glycosidic vinyl ethers, in the presence of weak Lewis acids (typically ZnCl2). The amphiphilic copolymers were obtained by deprotection, in acidic medium, of the hydroxy functions of the sugar of the moieties. The solubility characteristics of these copolymers are discussed with respect to the dimensions of the copolymers and to the hydrophilic/hydrophobic balance between the two blocks.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    U.V./visible spectroscopic study of the rac-Et(Ind)2ZrCl2/MAO olefin polymerization catalytic system, 2.Part 1: cf. ref.23 Investigation in CH2Cl2 (1998)
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 199 (1998), S. 1459-1464 
    Details
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The bathochromic shift of the metallocene absorption band of the system rac-Et(Ind)2ZrCl2/methylaluminoxane (MAO) in CH2Cl2 at 20°C proceeds in two distinct steps: for Al/Zr mole ratios in the range 20-50, a first bathochromic shift up to 440 nm is observed. It is explained by the formation of stable and unreactive ionic type species, most likely mixed dimer species (Zr-Al). Further addition of MAO (MAO/Zr 〉 50) is accompanied by a new and continuous bathochromic shift of the maximal wavelength corresponding to the formation of more dissociated zirconocenium species. In agreement with the results reported in toluene, the λmax changes of the U.V./visible spectrum of the rac-Et(Ind)2ZrCl2/MAO system were correlated with the catalytic activity obtained for the hex-1-ene polymerization.
    Additional Material: 8 Ill.
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  • 9
    Electronic Resource
    Electronic Resource
    Isospecific homo- and copolymerization of styrene with ethylene in the presence of VCl3, AlCl3 as catalyst (1996)
    Weinheim : Wiley-Blackwell
    Macromolecular Rapid Communications 17 (1996), S. 461-469 
    Details
    ISSN: 1022-1336
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The homopolymerization of styrene and its copolymerization with ethylene in the presence of a vanadium-based supported catalyst, {VCI3, 1 AICI3}, associated to triethylaluminium is examined. As indicated by means of 13C nuclear magnetic resoance and differential scanning calorimetry analysis, the homopolystyrenes obtained present a highly isotactic microstructure and are semicrystalline (melting temperature 220°C).In the case of styrene/ethylene random copolymerization, the formation of both, polyethylene blocks and isotactic polystyrene sequences was identified by analysis of the crude polymer. Solubility characteristics and structural characteristics from nuclear magnetic resonance spectra of these products support the formation of copolymers with ethylene and isotactic styrene blocks rather than that of two distinct homopolymers.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/marc.1996.030170704
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  • 10
    Electronic Resource
    Electronic Resource
    Living cationic polymerization of cyclohexyl vinyl ether (1994)
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 195 (1994), S. 217-227 
    Details
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The cationic polymerization of cyclohexyl vinyl ether (CHVE) initiated by α-halogeno ethers in the presence of a Lewis acid activator has been investigated first. In conditions leading to a living polymerization of alkyl vinyl ethers (ethyl, isobutyl, etc.), an extremely fast polymerization, accompanied by chain transfer reactions, is observed with CHVE. In fact, we have shown that the polymerization of this monomer may be directly initiated by the HI and HCl adducts of CHVE, in the absence of any electrophilic activator. However, even in these conditions, the polymerization cannot be controlled. A “living” polymerization of CHVE was finally obtained by addition of ammonium salts (NBu4X; X = Cl, Br, I) to the systems free of electrophilic activators. The added salts stabilize the α-halogeno ether chain ends and reduce the overall reactivity. Using this procedure, we have synthesized poly(CHVE)s with M̄n's ranging from 6 · 103 to 4 · 104 g · mol-1 (in good agreement with the predicted values assuming the formation of one polymer chain per initiator molecule) and narrow molecular weight distributions (M̄w/M̄n 〈 1,2). Though most of poly(alkyl vinyl ether)s exhibit glass transition temperatures far below 0°C, the glass transition temperature of the poly(CHVE) is close to +50°C, indicating that this monomer can be used as a precursor to rigid poly(vinyl ether) blocks.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1994.021950120
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