Crosslinked poly(ethylene oxide) modified with tetraalkylammonium salts as phase transfer catalyst

Abstract

Radiation crosslinked poly(ethylene oxide)s (PEO) modified with two tetraalkylammonium salts: allyldimethyldodecylammonium bromide and ethylmethacrylate dimethyldodecylammonium bromide were prepared. They have been characterized by elemental analysis, IR, 1H‐NMR spectra, and DSC measurements. Their activity as phase transfer catalysts (PTC) in the model displacement reaction of 1‐bromooctane with aqueous sodium cyanide were studied. The reaction kinetics were followed under pseudo‐first‐order conditions. Small amounts of onium salt inserted into the PEO network gave rise to a five time increase in the rate constant. The recovered catalysts could be re‐used without loss of activity. © 1995 John Wiley & Sons, Inc.

Sorption of Hydrophobic Compounds by Modified Poly(ethylene oxide) Networks

“…Two tetraalkylammonium salts, allyldimethyldodecylammonium bromide (denoted as D) and ethyl methacrylate dimethyldodecylammonium bromide (denoted as C), were prepared by previously reported methods [13,14] and characterized by IR-and 1 H NMR spectroscopy and elemental analysis. [12,15] Bromophenol blue (Fluka) was used as received. Solvents were benzene, methanol, ethanol, diethyl ether and distilled water.…”

“…[12,[15][16][17] Degassed 2 wt.-% aqueous solutions of commercial PEO (Badimol, "Neochim", M -w 1 000 000) were irradiated by c-rays with doses totaling 2 and 10 Mrad, respectively ( 60 Co source, 270 Krad/h). The samples were fragmented by mechanical stirring of the gels and liophilized.…”

“…The synthesis of alkylammonium salts immobilized on PEO is described in ref. [15] All modified samples were washed with distilled water and ethanol under vigorous stirring and then dried under vacuum at 35-40 8C. Dry networks were obtained as irregular particles in sizes of 0.5-1.5 mm.…”

“…[12,15] Table 2 shows the composition of the networks, their degree of quaternization and amphiphilic properties.…”

“…Apparently, the influence of the strongly hydrophobic dodecyl group dominates over the effect of polar ionic groups when the networks swell in water. As a result, all the PEO-D and PEO-C networks absorb less water then PEO-2 (Table 2; for comparison, the equilibrium swelling of a pure PEO network prepared by irradiation with 5 Mrad, PEO-5, was 17.1 [12,15] ). A more complicated behaviour of the modified networks in benzene is observed.…”