Oxypropylene Groups Research Articles

Effect of oxyethylene and oxypropylene groups on the interfacial structure and property of extended surfactants: Molecular simulation and experimental study

Extended surfactants including oxyethylene (EO) and oxypropylene (PO) groups have great potential applications in the fields of oil recovery, separation and extraction, fabric washing, medicine and cosmetics vehicles. In this work, the interfacial structure and dynamic property of six alkyl polyoxypropylene polyoxyethylene ether carboxylates (C12POmEOnC, m = 5 and 15, n = 5, 10 and 15) at the water/oil interface were investigated with interfacial tension (IFT) experiments and molecular dynamics (MD) simulations. C12PO15EO5C was found to reduce the experimental IFT value to the order of 10-3 mN/m. Further, the interfacial thickness, stretch degree, hydrogen bond number and radial distribution function were calculated and analyzed in detailed simulations. The simulation results demonstrated that long PO chain curled in a helical shape to wrap hydrophilic oxygen atoms in the oil phase and reached a compact arrangement on the interface but short PO chain could not; long EO chain partially laid flat on the interface (about 5 EO units) and partially extended into the aqueous phase bringing the hydrophilic oxygen atoms close to water molecules while forming vacancies on the water side. Therefore, C12PO15EO5C had the tightest interfacial arrangement. Theoretical and experimental results are in fairly good agreement and they will provide enlightening insights into the design and synthesis of more effective extended surfactants.

Physico-Chemical Properties and Efficiency of Demulsifiers based on Block Copolymers of Ethylene and Propylene Oxides

The investigation results about physico- chemical properties of block copolymers based on ethylene and propylene oxides and their solutions which may be used as demulsifiers for oil emulsions have been represented. The dependence of their physico-chemical properties on the content of oxyethylene and oxypropylene groups in the molecule has been determined. On the basis of the technological suitability a series of block copolymers was chosen and their demulsified ability was examined. The increase of ethylene oxide content in the macromolecule positively affects the blockcoplymer demulsified ability.

Investigation of physical and chemical properties of nonionic demulsifiers based on ethylene and propylene oxides

В статті наведені результати досліджень фізико-хімічних властивостей блоккополімерів на основі оксидів етилену та пропілену та їх розчинів, які можуть бути використані як деемульгатори нафтових емульсій. Встановлено залежність властивостей блоккополімерів та їх розчинів від вмісту оксіетиленових та оксипропіленових груп в молекулі. На основі технологічної придатності відібрані блоккополімери та їх розчини для досліджень їх деемульгуюючої здатності.

New foamed plastic based on polyetherols obtained from 6‐aminouracil, ethylene carbonate, and propylene oxide

AbstractPolyetherols with 1,3‐pyrimidine ring including both oxyethylene and oxypropylene groups were obtained in reactions of 6‐aminouracil with ethylene carbonate and propylene oxide. The structure of the products was analyzed by spectral methods. Some physical properties of polyetherols were investigated. The polyetherols were used as polyol components to obtain polyurethane foams. Some properties of the foams such as apparent density, absorption of water, linear dimensions stability, thermal resistance, and compression strength were investigated. The foams obtained show an improved thermal stability. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Effect of Oxypropylene Chain Length on the Surface Properties of Dialkyl Glycerol Ether Nonionic Surfactants

In this work, as a continuation of our studies concerning the preparation and surface properties of nonionic surfactants, derivatives of 1,3-dialkoxy-2-propanols and 1,3-dialkoxy(oligooxypropylene)-2-propanols with oligooxypropylene chains have been synthesized and investigated. The surface activity of these compounds has been determined, i.e., critical micelle concentration (CMC), surface excess concentration (Γ), surface area demand per molecule (A), surface tension at CMC (γCMC), ΔGads°, and ΔGmic°. A linear decrease of the log CMC vs number of oxypropylene groups is observed, and based on the Shinoda equation the work of cohesion per oxypropylene group when passing from molecular to micellar state is calculated for 0.43 kT. The equivalent of CH2 in the aliphatic alcohol group is ca. 2.50 oxypropylene units. Surface properties of these surfactants, i.e., cloud point, wetting ability, contact angle, foam height, and emulsion stability type (O/W), have been determined as well.

Anionic copolymerisation of ethylene oxide and propylene oxide. Investigation of double-bond content by NMR spectroscopy

Copolymers of ethylene oxide and propylene oxide were prepared to low conversion at temperatures in the range 0–80 °C, and the number of unsaturated end groups relative to copolymerised oxypropylene groups in each sample was determined by NMR spectroscopy. The data were analysed to yield values of the two transfer constants, C tr, E and C tr, P , for proton abstraction by oxyethylene and oxypropylene oxyanions respectively, and, from the temperature dependences of C tr, E and C tr, P and relevant published data, values of the activation energies for the two transfer reactions.

Preparation and surface active properties of oxypropylated α-hydroxyacids, α-hydroxyesters and α-, β-alkane diols

A series of a-hydroxyacids RCH(OH)CO 2 H, α-hydroxyesters RCH(OH)CO 2 CH 3 and α, β-alkane diols was synthetized and condensed with 5-20 moles propylene oxide to obtain nonionic surfactants. Some of the physicochemical properties and the biodegradability of these products were examined. The results showed that the best wetting properties were obtained by the addition of 15 oxypropylene groups to methyl α-hydroxymyristate. The α-hydroxymyristic acid with 20 moles of propylene oxide gave the highest foam. Biodegradation studies indicated that increasing both the chain length of the hydrophobic alkyl chain or the number of oxypropylene groups in the adduct decreased biodegradation.

Adsorption of oligooxypropylenated amines at the aqueous solution—air interface: Homologous series of piperidine and morpholine derivatives

The surface tension isotherms for pure oligooxypropylenated piperidine and morpholine at the aqueous solution—air interface were determined and interpreted. The surface excess concentration, Γ, the surface area per molecule, A, and the standard free energy of adsorption, Δ G°, were calculated according to a new empirical adsorption equation. The standard free energy contribution for the oxypropylene group (PO) in morpholine derivatives,Δ G° (PO) = −3.34 kJ mol −1, is substantially lower than that for the PO group located in the piperidine derivatives, i.e. Δ G° (PO)= −3.12 kJ mol −1.

Coemulsion and electrodeposition properties of mixtures of polyoxypropylene‐modified cationic epoxy resin and nonionic trimethylolpropane–toluene diisocyanate–2‐ethylhexanol crosslinker

AbstractThe emulsification and electrodeposition properties of mixtures of polyoxypropylene‐(POP) modified cationic epoxy resin (III) and nonionic trimethylolpropane–toluene diisocyanate–2‐ethylhexanol (TMP–TDI–2EH, V) were investigated and the compositions of their electrodeposited films were obtained by Fourier Transform Infrared (FTIR) quantitative analysis to study the effects of “soft segment” (oxypropylene groups) contained in resin III on the coemulsion and electrophoretic behavior. The results indicate that the deposition yield and throwing power of emulsion of resin III are highly dependent on its average molecular weight (Mw). Resin III with higher Mw has higher deposition yield but lower throwing power. Moreover, the deposition yield of V/III coemulsion also increases with increasing the Mw of III. On the other hand, the throwing power of V/III coemulsion is not related to the Mw of III but is influenced by the amount of soft segments in III. Increasing soft segment content in III increases the throwing power of the coemulsion. Furthermore, at the conditions providing stable coemulsion, the composition of the electrodeposited film is almost equal to the resin composition of the coemulsion. © 1993 John Wiley & Sons, Inc.

Coemulsion and electrodeposition properties of mixtures of a poly(oxypropylene)‐modified cationic epoxy resin and nonionic crosslinker system

AbstractThe emulsification and electrodeposition properties of mixtures of a poly(oxypropylene) (POP)‐modified cationic epoxy resin (III) and nonionic pentaerythritol/toluene diisocyanate/2‐ethylhexanol (PETOL‐TDI‐2EH, V) were investigated and the compositions of their electrodeposited films were obtained by Fourier Transform Infrared (FTIR) quantitative analysis to study the effects of soft segments (oxypropylene groups) contained in resins III on the coemulsion and electrophoretic behavior.The results indicate that the deposition yield and throwing power of an emulsion of individual III are deeply affected by its average molecular weight (AMW). Resin III with higher AMW has higher deposition yield but lower throwing power. Moreover, the deposition yield of V/III coemulsion also increases with increasing the AMW of III. On the other hand, the throwing power of V/III coemulsion is not related to the AMW of III but affected by the amount of soft segments in III. Increasing “Soft segment” Content in III increases the throwing power of coemulsion. Furthermore, at the conditions providing stable coemulsion, the composition of electrodeposited film is almost equal to the resin composition of coemulsion.

Interaction of segmented polyurethanes and polyurethane‐ureas with water

AbstractSorption of water vapor by oligomeric homopolymers and triblock copolymers of ethylene oxide and propylene oxide, and by polyurethanes and polyurethane ‐ ureas derived from them is discussed. While the sorption isotherms (plots of ψ1 vs a1, where ψ is he volume fraction of sorbed water and a1 is activity) for most polymers investigated here are smooth and convex towards the abscissa, those found with polyurethane‐ureas containing long hard blocks have a “toe” at low activities. The plots of a1/ψ1 vs a1 are shown to facilitate the analysis of data and the interpretation in terms of the D'Arcy‐Watt theory.Smooth isotherms are fitted by a simple equation with two parameters. The first is related to the limiting value, χ0, (at ψ1 → 0) of the χ parameter characterizing the polymer‐water interaction. The dependences of χ0 on the polymer composition (content of hard segments or oxyethylene units) can provide information on the interaction between hard and soft segments.The second parameter is used in the computation of parameters characterizing the clustering tendency of water molecules. This tendency depends mainly on the content of oxypropylene units but is also raised by urethane or urea groups, though not so much as by oxypropylene groups.

Der Einfluß der Struktur polyoxypropylierter sekundärer Amine auf ihre Adsorption an der Grenzfläche Wäßrige Lösung-Luft / Structural Effects of Polyoxypropylated Secondary Amines on their Adsorption at the Aqueous Solution - Air Interface

A new empirical equation dealing with the adsorption process of the whole group of nonionic surface active substances at the aqueous solution - air interface has been applied to polyoxypropylated secondary amines. Surface area per molecule and surface excess of studied surfactants as well as the hydropholic/hydrophobic nature of oxypropylene groups have been evaluated and discussed

Biodegradation of nonionic surfactants containing propylene oxide

AbstractInsertion of oxypropylene groups into the polyoxyethylene chain of fatty and oxo alcohol ethoxylates decreased the rate and extent of biodegradation. The magnitude of the effects was proportional to the PO‐block size and the extent of branching in the alcohol. Data are presented from a series of PO‐containing nonionic surfactants in semi‐continuous activated sludge reactors over test periods of up to 12 weeks. Bioassays performed on effluents from the SCAS units showed little or no toxicity due to residual degradation metabolities towardPimephales promelas andDaphnia pulex and a stimulatory effect onSelenastrum capricornutum growth rate.

Physicochemical and protective properties of hydroxypropylated ethanolamides

This article reports on a study of the physicochemical, electrochemical, and protective properties of nonionic surfactants. It examines oxypropylated monoethanolamides (MEA) with the general formula R-CON(C/sub 3/H/sub 6/O) /SUB x/ HC/sub 2/H/sub 4/O(C/sub 3/H/sub 6/O) /SUB y/ H and oxypropylated diethanolamides (DEA) with the general formula R'CON(C/sub 2/H/sub 4/O)/sub 2/(C/sub 3/H/sub 6/O) /SUB x/ H(C/sub 3/ H/sub 6/O) /SUB y/ H, where R is a C/sub 10/-C/sub 16/ alkyl radical; R' is a C/sub 10/-C/sub 13/ alkyl radical; n=x + y is the number of oxypropylene groups, ranging from 1 to 10. An increase in the number of added oxypropylene groups is accompanied by decreases in the refractive index, nitrogen content, and solid point, along with an increase in the density of the products that are obtained. These studies of the relationships in the variation of physicochemical and protective properties of compounds based on ethanolamides may contribute to the development of protective surfactants for petroleum products with the particular combinations of properties and performance indices that may be required for specific purposes.

The effect of polyoxypropylene chain length on the critical micelle concentration of propylene oxide—ethylene oxide block copolymers

“RPE” block copolymer surfactants obtained by the addition of ethylene oxide to n-hexyl and n-heptyl ethers of mono- to tetrapropylene glycol are described. The critical micelle concentration of the copolymers in aqueous solution were determined by surface tension and dye absorption method. A linear decrease of log [CMC] vs number of propylene oxide units in copolymer molecule was observed. The change of work of cohesion per oxypropylene group when it passes from molecular into micellar state, calculated from the Shinoda equation ( Shinoda, K., Nakagawa, T., Tamamushi, B., and Isemura, T., “Colloidal Surfactants.” Academic Press, 1963), was 0.43 and 0.42 kT for n-hexyl and n-heptyl derivatives, respectively.

Gas-chromatographic analysis of polyurethane polyethers by using a mixed anhydride reagent for the cleavage of ether linkages

The polyethers formed from propylene glycol, glycerol, trimethylol-propane [1,1,1-tris(hydroxymethyl)propane], pentaerythritol, sorbitol, triethanolamine, 1,2-diaminoethane and 2,2′-diaminodiethylamine, and which are used in the manufacture of polyurethane foams, have been qualitatively analysed by gas chromatography after conversion of the base compounds into their corresponding acetates by using the mixed anhydride of acetic and toluene-p-sulphonic acids as a reagent for cleavage for the ether linkages. The polyethers are allowed to react with the reagent at 120 °C for 2 hours. The reaction products are extracted with diethyl ether and the concentrated extract is subjected to gas chromatography. As, under appropriate conditions, the peaks of these acetates appear at different positions, they were easily distinguished.The proportions of oxyethylene and oxypropylene groups in the polyethers can also be determined by gas-chromatographic analysis of the acetylation products.

Properties of nonionic surfactants based on cyclohexanol and its derivatives

1. The variation in density, solubility, freezing point, and demulsifying power, with the size and ratio of hydrophobic to hydrophilic units in the molecule has been determined for a number of block copolymers of ethylene and propylene oxides. 2. The block copolymer based on dimethylcyclohexanol containing 70% propylene glycol groups has the highest demulsifying power. 3. An increase in oxypropylene groups lowers the freezing point, the density and the solubility in water.