Oxyethylene and oxypropylene

Ethylene oxide and propylene oxide adducts of polyhydric alcohols and amines are widely used as polyethers in the production of polyurethane foams by reaction with diisocyanate. The physical properties of the foams depend to a certain extent on the chemical structure of these polyethers, so it is very important to establish a method for the identification of the base compounds and for the determination of the proportions of their oxyethylene and oxypropylene groups. 

Mathias and Mellor split the polyethers with hydrobromic acid - acetic acid to give bromo compounds, which were analysed by gas chromatography. 

Cervenka and Merrall have investigated the application of acidic dehydration of ethylene oxide-propylene oxide condensates in bromonapthalene in the presence of p-toluene sulphonic acid to the elucidation of the molecular structure and monomer sequence of these polymers. Gas chromatography was used to determine dehydration products. 

Studies on poly(ethylene glycol) and poly(propylene glycol) homopolymers showed that dioxane and its derivatives (eg. methyl dioxone 1.4) are not the only reaction products. Dehydration of poly(ethylene glycol) gave three products that of poly(prop-ylene glycol) six products. The majority of them were identified. 

Cervenka and Merrall conclude that results on homopolymers, their blends and model copolymers of different chain architectures demonstrate that acidic dehydration is capable of distinguishing ethylene oxide-propylene oxide copolymers of different structures, giving correct absolute values of overall monomer contents and also ranking polyols according to their degrees of randomness. 

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A more detailed study on foam behaviour and the features of foam column destruction has been performed in [69-71]. Various kinds of surfactants, different foam column heights, foam dispersity and temperatures, were investigated at Ap pgH, including the range of critical pressure drops pcr. The kinetics of establishing a capillary pressure was also accounted for. Used were ionic (NaDoS) and nonionic (Triton-X-100) surfactants as well as some silicon-organic compounds which differed by the number of siloxane, dimethylsiloxane, oxyethylene and oxypropylene groups (KS-1, BS-3 and KEP-2). 

U.S. 4,247,425 (1981) Egan et al. (Sherex Chemical) Nonionic with polyoxyalkylene chain composed of randomly distributed oxyethylene and oxypropylene residues Low eye and skin irritation... 

To determine oxyethylene and oxypropylene groups in the ethylene oxide propylene oxide copolymers, and polyols, the samples were oxypropylated and then oxyethylated, and these were then decomposed as described above for the determination of the polyol base compounds. The FFAP column is operated isothermally at 65 °C and the flow-rate of the carrier gas is regulated at 60 ml/min. 

Tsuji and Kounishi extended this method to the identification of base compounds and the determination of their oxyethylene and oxypropylene group contents (Method 60). 

Chem. Descrip. Linear polymer of equal parts oxyethylene and oxypropylene Ionic Nature Nonionic CAS 9003-11-6... 

Diiodopropane reacts similarly to give isopropyliodide and byproducts) One mole of titratable iodine is produced for each alkylene oxide unit. The liberated iodine is titrated with sodium thiosulfate solution. Alternatively, the cleavage products may be determined by gas chromatography, permitting distinguishing between oxyethylene and oxypropylene content. A number of studies of this reaction have appeared. They indicate that only about 80% yield is obtained in the reaction of PO units with HI (15). For practical reasons, the unstable HI reactant is usually replaced with KI and phosphoric acid (12). 

Several studies have demonstrated the successful incoriDoration of [60]fullerene into polymeric stmctures by following two general concepts (i) in-chain addition, so called pearl necklace type polymers or (ii) on-chain addition pendant polymers. Pendant copolymers emerge predominantly from the controlled mono- and multiple functionalization of the fullerene core with different amine-, azide-, ethylene propylene terjDolymer, polystyrene, poly(oxyethylene) and poly(oxypropylene) precursors [63,64,65,66,62 and 66]. On the other hand, (-CggPd-) polymers of the pearl necklace type were fonned via the periodic linkage of [60]fullerene and Pd monomer units after their initial reaction with thep-xy y ene diradical [69,70 and 71]. 

Wanka G, Floffman FI and Ulbrict W 1990 The aggregation behavior of poly-(oxyethylene)-poly(oxypropylene)-poly-(oxyethylene)-block copolymers in aqueous solutions Colloid Polym. Sc/. 268 101-17... 

Polyall lene Oxide Block Copolymers. The higher alkylene oxides derived from propjiene, butylene, styrene (qv), and cyclohexene react with active oxygens in a manner analogous to the reaction of ethylene oxide. Because the hydrophilic oxygen constitutes a smaller proportion of these molecules, the net effect is that the oxides, unlike ethylene oxide, are hydrophobic. The higher oxides are not used commercially as surfactant raw materials except for minor quantities that are employed as chain terminators in polyoxyethylene surfactants to lower the foaming tendency. The hydrophobic nature of propylene oxide units, —CH(CH2)CH20—, has been utilized in several ways in the manufacture of surfactants. Manufacture, properties, and uses of poly(oxyethylene- (9-oxypropylene) have been reviewed (98). 

Porous membranes have been prepared by leaching an additive from films and tubes of PCL (64,72). The procedure involves extrusion or casting blends of PCL and Pluronic F68, the latter being an FDA-approved oxyethylene-co-oxypropylene triblock copolymer. Treatment of the phase-separated blend with aqueous acetone or aqueous alcohols causes both swelling of the polymer and extraction of the Pluronic F68. The induced pore size and void volume may be controlled by the time, temperature, and solvent composition. 

Wanka, G Hoffman, H Ulbricht, W, Phase Diagrams and Aggregation Behavior of Poly (oxyethylene)-Poly(oxypropylene)-Poly(exyethylene) Triblock copolymers in Aqueous Solutions, Macromolecules 27, 4145, 1994. 

Polyglycols, especially poly(propylene-l,2- or -1,3-glycol). Poly(oxyethylene) and poly(oxypropylene) block copolymers have relatively poor foam control [536]. 

Several recent reviews have included a discussion of the ordered micellar phase phase behaviour of poly(oxyethylene)/poly(oxypropylene) copolymers (Alexandridis and Hatton 1995 Chu and Zhou 1996) and poly(oxyethylene)/ poly(oxybutylene) copolymers (Booth et al, 1997),... 

S. A. Leharne, E. Eagland, and N. J. Crowther. 1994. An investigation of dilute aqueous solution behavior of poly(oxyethylene )poly(oxypropylene)-poly(oxyethylene) block copolymerlsangmuir 10 4001—4005. 

P. Chekhonin, I. R. Nazarova, and V. A. Kabanov. 1992. A new class of drug carriers micelles of poly(oxyethylene)-poly(oxypropylene) block copolymers as microcontainers for drug targeting from blood in brain.J. Control. Rel22 141-158. 

Kabanov, A. V., I. R. Nazarrova, I. V. Asta eva, E. V. Batrakova, V. Y. Alakhov, A. A. Yaroslavov, and V. A. Kabanov. 1995. Micelle formation and solubilization of luorescent probes in poly(oxyethylene-b-oxypropylene-boxyethylene) solution /lacromoleculeS8 2303-2314. 

Zhou, Z. and B. Chu. 1994. Phase behavior and association properties of poly(oxypropylene)-poly(oxyethylene)-poly(oxypropylene) triblock copolymer in aqueous soluftdacromolecule 7 2025-2033. 

Materials. Pluronic FI27 was a gift from Pechiney Ugine Kuhlmann and was used as received. Pluronic F127 is an ABA poly(oxyethylene)-poly(oxypropylene)-poly(oxyethylene) block copolymer containing approximately 70% oxyethylene with a nominal molecular weight of 1.15 x 10. ... 

Attwood, D. Collett, J.H. Tait, J.C. The micellar properties of the poly(oxyethylene)-poly(oxypropylene) copolymer Pluronic FI27 in water and electrolyte solution. International Journal of Pharmaceutics 1985, 26, 25-33. 

Kabanov AV, Nazarova IR, Astafieva IV, et al. Micelle formation and solubilization of fluorescent probes in poly-(oxyethylene-b-oxypropylene-b-oxyethylene) solutions. Macromolecules 1995 28 2303-2314. 

Poloxamers are synthetic block copolymers of hydrophilic poly(oxyethylene) and hydro-phobic poly(oxypropylene) with the general formula E ,P E , where E = oxyethylene (OCH2 CH2) and P = oxypropylene (OCH2CHCH3) and... 

Figure 6.36 The Pluronic grid for (a) the poly(oxyethylene)-poly(oxypropylene)-poly(oxyethylene) [Pluronic] series and (b) the poly(oxypropylene)-poly(oxyethylene)-poly(oxypropylene) [Pluronic R] series of block copolymers.

Poly(oxyethylene) -poly(oxypropylene) -poly(oxyethylene) block copolymers, known commercially as Pluronic or poloxamer surfactants, are used as emulsifiers. Some form micellar aggregates and in aqueous solutions above a critical micelle concentration, in which the hydrophobic central block associates with... 

Poly(dimethylsiloxane-co-oxyethylene-co-oxypropylene) is used as a surfactant, dispersant, and wetting agent, while poly[bisphenol A bis(oxyranylmethyl) ether]-co-poly(dimethylsiloxane) is used as an epoxy resin. More complicated silicone copolymers also were synthesized such as the silicone polyetherimide shown below ... 

The poly(oxyethylene)-poly(oxypropylene)-poly(oxyethylene) block copolymers were also used to gel the continuous aqueous phase. Poloxamers may be used as the secondary hydrophilic surfactant in the preparation of the w/o/w system, and the finished emulsion is then irradiated. The polymerisation reaction can be monitored by cone-and-plate viscometry. Fig. 9 shows the flow curve obtained for a water/isopropyl myristate/water emulsion as a function of the radiation dose. As the dose of y-irradiation is increased, the viscosity of the w/o/w emulsion increased up to a gel-point1. The gel-point of the emulsion is dependent on the type and concentration of poloxamer. In the example shown, prepared using a mixture of 5% (w/v) Pluronic F87 and 5% (w/v) Pluronic F88 in the external phase, the gel-point was reached at 4.2 (Fig. 9). Fig. 10 shows the changes in the properties of irradiated systems on storage. 

TAB Taboada, P., Barbosa, S., and Mosquera, V., Thermodynamic properties of a diblock copolymer of poly(oxyethylene) and poly(oxypropylene) in aqueous solution,... 

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