Search results for "Azobisisobutyronitrile"
showing 7 items of 7 documents
Peroxodisulfate as a chemical initiator for methacrylate-ester monolithic columns for capillary electrochromatography
2008
Organic monolithic stationary phases for CEC were synthesized in situ in fused-silica capillaries. Polymerization mixtures were composed of butyl methacrylate, ethylene dimethacrylate, and [2-(methacryloyloxy)ethyl]trimethyl ammonium chloride in the presence of a porogenic solvent, using ammonium peroxodisulfate as chemical initiator, and N,N,N',N'-tetramethylethylenediamine to activate the reaction. The influence of the amount of initiator, temperature, and composition of porogenic solvent on the physical and chromatographic properties of monolithic stationary phases has been investigated. A minimum plate height of 14.5 microm was obtained at 18 wt% of 1,4-butanediol in the polymerization …
Nachweis des di-2-cyanoisopropylperoxides bei der zersetzung von azoisobuttersäuredinitril in gegenwart von sauerstoff
1970
Das Di-2-cyanoisopropylperoxid entsteht in etwa 5-proz. Ausbeute bei der Zersetzung von Azoisobuttersaredinitril unter Sauerstoff in Isobutyronitril als Losungsmittel. Thermisch zerfallt das Peroxid est oberhalb von 120°C mit mesbarer Geschwindigkeit in einer Reaktion erster Ordnung. Die Aktivierungsenergie, in Cumol als Losungsmittel, wurde zu 37,9 kcal · mol−1 bestimmt. Werte fur die Zerfallskonstante bei 140°C sind in Cumol 0,057 h−1, in tert-Butylbenzol 0,073 h−1, in Chlorbenzol 0,18 h−1 und in o-Dichlorbenzol 0,23 h−1. Di-2-cyanoisopropylperoxide is formed when azobisisobutyronitrile is decomposed under oxygen in isobutyronitrile as a solvent. The yield amounts to ca. 5%. Thermal decom…
Initiierte autoxydation von isotaktischem und ataktischem polybuten-1 in lösung
1968
Isotaktisches und ataktisches Polybuten-1 (PB) wurden bei 70,6°C in brombenzolischer Losung mit Azoisobuttersauredinitril als Initiator mit Sauerstoff oxydiert. Die oxydierten Proben wurden isoliert, und der Gehalt an Hydroperoxidgruppen wurde mit Hilfe von Triphenylphosphin bestimint. Cyclische Peroxide, die bei oxydiertem isotaktischem Polybuten 1 moglich sind, konnen nicht mit Triphenylphosphin bestimmt werden, da sie zerfallen, bevor sie mit dem Phosphin reagieren. Dies wurde an niedermolekularen Modellverbindungen uberpruft. Unter den Reaktionsbedingungen war die kinetische Kettenlange so klein (1 bis 2), das deutliche Unterschiede der Oxydation von isotaktischem und ataktischem Polybu…
Straightforward preparation of highly loaded MWCNT-polyamine hybrids and their application in catalysis
2020
Multiwalled carbon nanotubes (MWCNTs) were easily and efficiently functionalised with highly cross-linked polyamines. The radical polymerisation of two bis-vinylimidazolium salts in the presence of pristine MWCNTs and azobisisobutyronitrile (AIBN) as a radical initiator led to the formation of materials with a high functionalisation degree. The subsequent treatment with sodium borohydride gave rise to the reduction of imidazolium moieties with the concomitant formation of secondary and tertiary amino groups. The obtained materials were characterised by thermogravimetric analysis (TGA), elemental analysis, solid state 13C-NMR, Fourier-transform infrared spectroscopy (FT-IR), transmission ele…
Comparison on photo-initiators for the preparation of methacrylate monolithic columns for capillary electrochromatography.
2010
The synthesis of lauryl methacrylate monoliths for capillary electrochromatography by UV polymerization using several free-radical initiators (alpha,alpha'-azobisisobutyronitrile, 2,2-dimethoxy-2-phenylacetophenone, dibenzoyl peroxide (BPO) and lauroyl peroxide (LPO)) has been investigated. Using a 1,4-butanediol/1-propanol mixture as porogenic solvent, the influence of each initiator and its content on the morphological and electrochromatographical properties of beds was evaluated. Under their respective optimum content, satisfactory separations of a test mixture of PAHs with similar efficiencies (minimum plate heights of 8.0-12.7 microm obtained from Van Deemter plots) were achieved for t…
Multi-layered, covalently supported ionic liquid phase (mlc-SILP) as highly cross-linked support for recyclable palladium catalysts for the suzuki re…
2011
The reaction between an excess of 1,4-bis(3-vinylimidazolium-1-yl) bromide and a mercaptopropyl-modified amorphous silica gel or ordered mesoporous silica SBA-15 in the presence of azobisisobutyronitrile (AIBN) afforded new materials, which have a high loading of imidazolium moieties. These materials, which contain a highly cross-linked polymeric network, have been denoted as multi-layered, covalently supported ionic liquid phase (mlc-SILP) and have been used as support for palladium catalysts containing a high loading of the metal (10 wt%). Such materials were characterized by several techniques (13C magic angle spinning nuclear magnetic resonance, the Brunauer–Emmett–Teller technique, sma…
Hybrid methacrylate monolithic columns containing magnetic nanoparticles for capillary electrochromatography
2015
Abstract Vinylized iron oxide magnetic nanoparticles (VMNPs) were incorporated into polymethacrylate monolithic columns to develop novel stationary phases with enhanced separation performance. The VMNPs were dispersed in a polymerization mixture containing gycidyl methacrylate and ethylene glycol dimethacrylate as monomers, cyclohexanol and 1-dodecanol as porogens and azobisisobutyronitrile as initiator. The stability of the VMNPs in the polymerization mixture was investigated at several VMNP contents. Using short UV-polymerization times, polymeric beds with homogenously dispersed VMNPs were obtained. The novel stationary phases were characterized by scanning electron microscopy. The chroma…