Ethylene oxide-based

Paraformaldehyde/DMSO dissolves cellulose rapidly, with neghgible degradation, and forms the hydoxymethyl (methylol) derivative at Ce [ 140-142]. Therefore, cellulose derivatives at the secondary carbon atoms are easily obtained after (ready) hydrolysis of the methylol residue. Additionally, fresh formaldehyde may add to the methylol group, resulting in longer methylene oxide chains, that can be functionahzed at the terminal OH group, akin to non-ionic, ethylene oxide-based surfactants [143,144]. 

Hydrolysis of polyamide-based formulations with 6 N HC1 followed by TLC allows differentiation between a-aminocaproic acid (ACA) and hexamethylenedi-amine (HMD) (hydrolysis products of PA6 and PA6.6, respectively), even at low levels. The monomer composition (PA6/PA6.6 ratio) can be derived after chromatographic determination of the adipic acid (AA) content. Extraction of the hydrolysate with ether and derivatisa-tion allow the quantitative determination of fatty acids (from lubricants) by means of GC (Figure 3.27). Further HC1/HF treatment of the hydrolysis residue, which is composed of mineral fillers, CB and nonhydrolysable polymers (e.g. impact modifiers) permits determination of total IM and CB contents CB is measured quantitatively by means of TGA [157]. Acid hydrolysis of flame retarded polyamides allows to determine the adipic acid content (indicative of PA6.6) by means of HPLC, HCN content (indicative of melamine cyanurate) and fatty acid (indicative of a stearate) by means of GC [640]. Determination of ethylene oxide-based antistatic agents... 

The second important theoretical model of ethylene oxide, based on the model of cyclopropane developed by Coulson and Moffitt, was constructed independently by Cromwell and oo-workera, 8- 80 1 and by Cunningham and eg-workers.m Briefly, this approach eeta out to vary the carbon hybridization from jp to a value intermediate between sp and ep in such a way that loss of overlap energy is just... 

Gunther and co-workers have developed an exceedingly sensitive colorimetric assay for ethylene oxide based on tho intensely-blne deformed in the presence of lepidine (4-methylquinoline) 9 Other authors/47-274 however, have called attention to certain inadequacies in this method. 

Laeubli, M. and Kampus, B. (1995) Selectivity Enhancement on a Poly (butadiene-maleic acid) Coated Cation Phase Induced by Ethylene Oxide-based Complexing Agents, J. Chromatogr. A 706, 103-107. 

From the field desorption mass spectra of standard samples, a table for identification of poly(oxyethylene) alkylphenyl ethers and determination of the degree of polymerisation of ethylene oxide was constructed as shown in Table 6.1 n is the number of alkyl carbon atoms and m is the degree of polymerisation of ethylene oxide. When the field desorption mass spectrum having a peak pattern with the difference of 44m/z was obtained such as the peaks at 484, 528, 572, 616 and 660m/z, Table 6.1 would show that those peaks are due to poly(oxyethylene) nonylphenyl ethers with the degree of polymerisation of 6-10 of ethylene oxide. Table 6.2 also shows the identification of poly(oxyethylene) dialkylphenyl ethers and determination of the degree of polymerisation of ethylene oxide based on calculations of the molecular weight. 

Won Y-Y, Brannan AK, Davis HT et al (2002) Cryogenic transmission electron microscopy (cryo-TEM) of micelles and vesicles formed in water by poly(ethylene oxide)-based block copolymers. J Phys Chem B 106 3354-3364... 

Dhawan S, Varma M, Sinha VR. High molecular weight poly(ethylene oxide)-based drug delivery systems. Part 1 hydrogels and hydrophilic matrix systems. Pharm Technol 2005 29(5) 72-74, 76-80. 

Apicella A, Capello B, Del Nobile MA, La Rotonda MI, Mensitieri GL, Nicolais S, Seccia S (1994) Poly(ethylene oxide)-based delivery systems. In Ottenbrite M (ed) Polymeric drugs and drug administration. American Chemical Society, Washington DC... 

Elisseeff, J., Anseth, K., Sims, D., McIntosh,W., Randolph, M., Yaremchuk, M., and Langer, R. (1999b) Transdermal photopolymerization of poly (ethylene oxide)-based injectable hydrogels for tissue-engineered cartilage, Plastic Reconstr. Surg., 104,1014-1022. 

Ethylene. The catalytic oxidation of ethylene to ethylene oxide based on the invention of Lefort has been practiced commercially on a large scale. Ethylene oxide has become an important organic chemical, being used in the manufacture of ethylene glycol, ethanolamines, fi-phenylethyl alcohol, plastics, plasticizers, resins, insecticides, surface-active agents, solvents, explosives, etc. 

Ethylene Oxide by Direct OHdation of Ethylene. The ethylene oxide required for the preparation of glycol can also be obtained by the direct oxidation of ethylene. Air. and ethylene are reacted in the presence of a silver catalyst at 220-240 . Two reactors in series are used. The gas entering the first reactor contains 2.9 per cent by volume of ethylene, while the exit gases contain about 1.1 per cent ethylene oxide, 1.8 per cent carbon dioxide, and 0.9 per cent ethylene. This stream is enriched with ethylene to 2.9 per pent and introduced into the second reactor. The gas leaving this reactor contains 2.2 per cent ethylene oxide, 3.6 per cent carbon dioxide, and 0.9 per cent ethylene. About 90 per cent of the ethylene fed undergoes reaction. Approjomately 60 per cent is converted to ethylene oxide and 40 per cent to carbon dioxide. The over-all yield of ethylene oxide based on ethylene fed is 50-55 per cent. 

Mesoporous alumina samples have been synthesized using poly(ethylene oxide)-based nonionic surfactants. The effect that the addition of n-alkylamines to the synthesis gel has on the texture and thermal stability of mesoporous aluminas is studied. Textural and structural characterization using nitrogen adsorption, powder X-ray diffraction, a1 nuclear magnetic resonance and Fourier Transform infrared spectroscopy, as well as catalytic n-hexane hydroisomerization tests are performed. 

Poly(ethylene oxide)-Based Electrolyte System... 

The particular feature with ethylene oxide based surfactants is that their interaction with water is less favorable at higher temperatures. This leads to a decrease in the spontaneous monolayer curvature with temperature, explaining the transition from oil-in-water emulsions below the PIT to water-in-oil emulsion above the PIT. In the vicinity of the phase inversion temperature the energy barrier against co-alescence(lP) varies very strongly with temperature. For the system n-octane-Cj2E5-water the following approximate relation was obtained in terms of AT = T-Tj, where is the PIT (4) ... 

Nonionic ethylene oxide based surfactants are commonly used as emulsifiers. Since these surfactants are uncharged they are not able to generate stabilizing long-range electrostatic forces. Instead, they generate short-range... 

Figure 11 Cloud-point temperature of micellar solutions as a function of the ethylene oxide chain length the hydrophobic part is an alkyl chain with 8 ( ), 10 ( ), 12 ( ), or 16 ( ) carbon atoms. Data from Ref. 51. The sjunbols ( ) represent the phase-inversion temperature for a 1 1 cyclohex-ane-water emulsion containing 5% of commercial ethylene oxide based emulsifiers having dodecylalkyl chains as a hydrophobic group. (Data from Ref. 54.)...

The scope of this interesting reaction recently has been extended to include the synthesis of similar multifunctional hydrophilic and hydrophobic monomers and oligomers derived from ethylene oxide-based acrylates and fluorinated and siloxane-based acrylates, respectively (7,8). This paper describes the synthesis, characterization and possible biomedical applications of these new acrylic monomers and oligomers. 

Figure 3. Synthesis of ethylene oxide-based multifunctional acrylic vinyl oligomers.

When conducting the ROMP of norbornene or cyclooctadiene in miniemulsions [82], two approaches were followed (i) addition of a catalyst solution to a miniemulsion of the monomer and (ii) addition of the monomer to a miniemulsion of Grubbs catalyst in water. With the first approach it was possible to synthesize stable latexes with a high conversion, whereas for the second approach particles of >400 nm were created, without coagulum, but with 100% conversion. Subsequently, a water-soluble ruthenium carbene complex [poly(ethylene oxide)-based catalyst] was prepared and used in the direct miniemulsion ROMP of norbornene [83], whereby particles of 200-250 nm were produced. The catalytic polymerization of norbornene in direct miniemulsion was also carried out in the presence of an oil-soluble catalyst generated in situ, or with a water-soluble catalyst [84] the reaction was faster when using the oil-soluble catalyst. Helical-substituted polyacetylene could be efficiently polymerized in direct miniemulsion to yield a latex with particles that ranged between 60 and 400 nm in size, and which displayed an intense circular dichroism [85] that increased as the particle size decreased. The films were prepared from dried miniemulsion latexes that had been mixed with poly(vinyl alcohol) (PVA) in order to conserve the optical activity. 

Moad, G., Dean, K., Edmond, L., Kukaleva, N., Li, G., Mayadunne, R. T. A., Rfaender, R., Schneider, A., Simon, G., and Wermter, H. 2005. Non-ionic, poly(ethylene oxide)-based surfactants as intercalants/dispersants/exfoliants for p>oly(propylene)-clay nanocomposites. Macromolectdar Materials and Engineering 291 37-52. 

M. Egashira, B. Scrosati, M. Armand, S. Beranger, C. Michot, Electrochem. Solid-State Lett. 2003,6, A71-A73. Lithium dicyanotriazolate as a lithium salt for poly(ethylene oxide) based polymer electrolytes. 

---