Phosphonium salts. III. The action of cyanide ion and other nucleophiles on some bis-phosphonium salts

Brophy, JJ; Gallagher, M. J.

doi:10.1071/ch9691405

Cited by 10 publications

(6 citation statements)

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“…So, the maximum amount of mass loss occurs at the higher temperature. The initial degradation of clay or the first peak could be due to the Hoffmann-type elimination reaction in phosphonium salts 23 in presence of hydroxyl groups of clay which causes the detachment of surfactants from clay surface. The second degradation or the second peak is due to the degradation of the byproducts of the above reaction.…”

Section: Resultsmentioning

confidence: 99%

Phosphonium‐based layered silicate—Poly(ethylene terephthalate) nanocomposites: Stability, thermal and mechanical properties

Patro

Khakhar

Misra

2009

J of Applied Polymer Sci

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PET-clay nanocomposites were prepared using alkyl quaternary ammonium and phosphonium modified clays by melt-mixing at 280 C using a micro twin screw extruder. The latter clays were prepared by synthesizing phosphonium surfactants using a simple onestep method followed by a cation exchange reaction. The onset temperature of decomposition (T onset ) for phosphonium clays (>300 C) was found to be significantly higher than that of ammonium clays (around 240 C). The clay modified with a lower concentration (0.8 meq) of phosphonium surfactant showed a higher T onset as compared to the clay modified with a higher concentration (1.5 meq) of surfactants. Nanocomposites prepared with octadecyltriphenyl phosphonium (C18P) modified clay showed a higher extent of polymer intercalation as compared with benzyltriphenylphosphonium (BTP) and dodecyltriphenylphosphonium (C12P) modified clays. The nanocomposites prepared with ammonium clays showed a significant decrease in the molecular weight of PET during processing due to thermal degradation of ammonium surfactants. This resulted in a substantial decrease in the mechanical properties. The molecular weight of PET was not considerably reduced during processing upon addition of phosphonium clay. The nanocomposites prepared using phosphonium clays showed an improvement in thermal properties as compared with ammonium clay-based nanocomposites. T onset increased significantly in the phosphonium clay-based nanocomposites and was higher for nanocomposites which contained clay modified with lower amount of surfactant. The tensile strength decreased slightly; however, the modulus showed a significant improvement upon addition of phosphonium clays, as compared with PET. Elongation at break decreased sharply with clay.

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Section: Resultsmentioning

confidence: 99%

Phosphonium‐based layered silicate—Poly(ethylene terephthalate) nanocomposites: Stability, thermal and mechanical properties

Patro

Khakhar

Misra

2009

J of Applied Polymer Sci

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“…There was no other significant mass loss for unmodified clay up to 570 C. In the case of 30B organoclays, however, the major mass loss occurred in the temperature range of 240-420 C. Quaternary ammonium ions presented in 30B clays started to degrade at the onset of decomposition temperature (T 0 ) of 240 C. This temperature is below the PET processing temperature of 300 C. Significant increases in T 0 were observed for clays modified with C1C4-Im and 3C6C14-Ph to give values of 375 C and 490 C, respectively. The initial degradation of clays modified with these ILs occurs because of the Hoffmann-type elimination reaction in phosphonium and imidazolium salts [30]. Hydroxyl groups present in clay result in detachment of surfactants from the clay surface at high temperatures.…”

Section: Thermal Gravimetric Analysismentioning

confidence: 99%

Novel preparation method for improving the dispersion of ionic liquid‐modified montmorillonite in poly(ethylene terephthalate)

2014

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Thermally stable ionic liquids (ILs) were used to modify clay nanoparticles for use in the preparation of poly(ethylene terephthalate)/clay nanocomposites. Nanoclays with smaller particle size distributions were prepared with a two-step centrifugation method that removed large particles from commercial montmorillonite (MMT). Scanning electron microscopy of aqueous dispersions of MMT and centrifuged clay (CMMT) illustrated that the average particle size of CMMT in water was much lower than that of MMT in water. Both CMMT and MMT were modified with imidazolium-and phosphonium-based ILs. Fourier transform infrared spectroscopy revealed that the surfactants were associated with the clay surface. Thermal gravimetric analysis results indicated that clays modified with thermally stable ILs degraded above 300 C and could survive PET processing temperatures. Transmission electron microscopy for nanocomposites revealed an improvement in the dispersion of centrifuged nanoclays (modified with both imidazolium and phosphonium ILs) into the polymer matrix compared to noncentrifuged modified MMT with larger particle sizes. X-ray diffraction and differential scanning calorimetry data indicated that particle size distributions have a significant effect on the dispersion and rate of crystallization of nanoclays modified with imidazolium surfactants. There was, however, a less important effect of centrifugation on the dispersion of nanoclays modified with phosphonium surfactants. POLYM. COMPOS., 00:000-000,

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“…(2-Dibutylamino-athyl)triphenylphosphonium-bromid (13 5(1,2)= 6, 5(2,P)=20, 2 H, 2 H-C(2));3,96 ( d x t. J ( I , P ) z 12, 2 H, 2 H-C (1)). ; 7,58-8,lO (m, 15 H, 3 C6H5 : 4,05-4,40 und 4,45-4, 78 (2m, 4 H , CH2CHzP) ; 7,50-8,lO (m. 16 H, 3 C6H5, H-C(3')); 8,48 (s, 1 H, H-C(5')).…”

Section: Experimenteller Teilmentioning

confidence: 99%

“…-'H-NMR. : 2,35 (m,4 H,2 CH2CH2P);3,0 (m,5 H,nach YIide aus den Triphenylphosphonium-bromiden [11][12][13][14][15][16][17] und Umsetzungen mit Carbonylverbindungen. -Allgemeine Methode.…”

Section: Experimenteller Teilunclassified

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Die Aminoalkylierung von Carbonylverbindungen mit Hilfe der Wittig‐Reaktion

Marxer

Leutert

1978

Helvetica Chimica Acta

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The Wittig reaction would be a very suitable way to replace the carbonyl group in aldehydes and ketones by a 2-amino-ethylidene group if a simple and convenient method could be devised for synthesizing (2-amino-ethy1)triphenylphosphonium bromides 3. We have synthesized compounds of type like (2-dialkylaminoethyl)-, (2-morpholino-ethyl)-, (2-( 1-imidazoly1)ethyl)-, and (2-( 1-triazoly1)ethyl)-triphenylphosphonium bromides (cf. Table I ) , by melting at 150" the hydrobromides of triphenylphosphine and of the appropriate 2-amino-ethanol. The phosphonium bromides of type 3 could be converted with ketones by the Wittig reaction into the desired amino-ethylidene compounds of type 2, e.g. 18-22 (Table 2). In the case of the reaction with 4-chlorobenzaldehyde the steric course of the transformation was studied, and conditions were found favoring either cis or trans compounds (e.g. 27a or 27b in the reaction of the phosphonium bromide 11, cf. Table 3).Eine der meistgebrauchten Methoden zum Ersatz der Carbonylgruppe von Aldehyden und Ketonen durch eine Aminoalkyl-Seitenkette ist die 1941 gefundene Grignard-Reaktion mit Dialkylaminopropyl-magnesiumchlorid [4]; sie gelingt jedoch nicht beim Venvenden von N, N-Dialkyl-2-chlorathylamin, da sich dessen magnesium-organische Verbindung sofort zu Athylen fragmentiert. Zur Herstellung eines Aminoalkohols 1, bei dem Amino-und Alkoholgruppe durch zwei C-Atome getrennt sind, miissen daher mehrstufige Wege in Kauf genommen werden (z. B. Mannich-oder Reformatzki-Reaktion, gefolgt von mehreren anschliessenden Schritten). Die aus dem Aminoalkohol 1 (Schema 1) durch Wasserabspaltung erhaltliche ungesattigte Verbindung 2 sollte aber durch Wittig-Reaktion einer Carbonylverbindung mit einem P-Amino-Ylid, wie 3a, zuganglich sein. In der Literatur sind nur zwei solche Umwandlungen beschrieben [6] [7] (vgl. unten), 1) *) Diese Mitt. sol1 als 9.Mitt. der fruher begonnenen Reihe gelten (s. [I]) und besteht aus Teilen der Dissertation von T. L. [2].Korrespondenz ist an diesen Autor erbeten.

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Phosphonium salts. III. The action of cyanide ion and other nucleophiles on some bis-phosphonium salts

Cited by 10 publications

References 0 publications

Phosphonium‐based layered silicate—Poly(ethylene terephthalate) nanocomposites: Stability, thermal and mechanical properties

Phosphonium‐based layered silicate—Poly(ethylene terephthalate) nanocomposites: Stability, thermal and mechanical properties

Novel preparation method for improving the dispersion of ionic liquid‐modified montmorillonite in poly(ethylene terephthalate)

Die Aminoalkylierung von Carbonylverbindungen mit Hilfe der Wittig‐Reaktion

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