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Terminal Double Bond (terminal + double_bond)

Distribution by Scientific Domains
Polymers and Materials Science60%
Chemistry40%

Selected Abstracts

ChemInform Abstract: Titanocene(II)-Promoted Reaction of gem-Dihalides Possessing a Terminal Double Bond.

CHEMINFORM, Issue 31 2001
New Intramolecular Cyclopropanation.
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Iron(III) Chloride-Catalyzed Direct Sulfonylation of Alcohols with Sodium Arenesulfinates

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2010
M. Amarnath Reddy
Abstract A new protocol for the direct sulfonylation of benzylic, allylic and homoallylic alcohols with sodium arenesulfinates is described by using iron(III) chloride as a catalyst and chlorotrimethylsilane as an additive. This method requires no preactivation of alcohols. Surprisingly in the reaction with homoallyl alcohols nucleophilic addition of sulfinate anion, occurs at the terminal double bond instead of nucleophic substitution at the alcohol. [source]

Unexpected Crosslinking During Acetoacetoxy Group Protection on Waterborne Crosslinkable Latexes

MACROMOLECULAR MATERIALS & ENGINEERING, Issue 10 2006
Iñigo González
Abstract Summary: The microstructure of the polymer synthesized by seeded semicontinuous emulsion copolymerization of AAEMA was investigated. It was found that the neutralization of the latexes with ammonia to protect acetoacetoxy functionality against hydrolysis during storage had a remarkable effect on the gel content. A base catalyzed Michael addition reaction between acetoacetoxy groups and terminal double bond (TDB) is proposed as responsible for the chain precrosslinking observed. The presence of TDB in the latexes was demonstrated by means of 1H NMR. Moreover, the chain precrosslinking affected the subsequent crosslinking reaction of the latex with diamines hindering chain interdiffusion and yielding poorer mechanical properties. Michael addition between AcAc functional groups and TDB, and final gel content of the MMA/BA/MAA latexes with different amounts of AAEMA. [source]

Design of new poly(ethylene) based materials by coordination (co)polymerization of macromonomers with ethylene,

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 9-10 2006
J.-F. Lahitte
Abstract The present work discusses first the homopolymerization of , -allyl, , -undecenyl or , -vinylbenzyl polystyrene (PS) macromonomers in the presence of selected early or late transition metal catalysts. Homopolymerization degrees were found to depend on the type of catalyst, the terminal double bond, the polymerization temperature and the concentration of the various species. Higher molar masses were reached at low temperatures and low catalyst and cocatalyst concentrations. Best results were obtained with the constrained geometry catalyst (CGC)-Ti. The same PS macromonomers were copolymerized with ethylene in the presence of the VERSIPOLTM catalyst to design a new type of poly(ethylene) based graft copolymer. The macromonomer weight percent content decreases with increasing ethylene pressure whereas the molar mass of the copolymer increases with ethylene pressure. The PS macromonomer content as well as the molar mass of the copolymer can be still increased by using ,,, -difunctional PS macromonomers. The dilute solution and solid-state behavior of these copolymers were examined and compared to those of poly(ethylenes) prepared under the same conditions. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Kinetic Modeling of Non-Linear Polymerization

MACROMOLECULAR SYMPOSIA, Issue 1 2006
Mário Rui P. F. N. Costa
Abstract Recent developments of a method based upon population balances of generating functions of polymer chain length distributions (CLD) are presented. The calculation of the CLD and how to take into account chain length dependent reactivity are discussed. Prediction of polymer properties is also possible but only easily done for the average molecular radius of gyration; some results are presented for a radical polymerization including transfer to polymer and propagation with terminal double bonds. [source]