Propylene oxide copolymers

Surface active agents are important components of foam formulations. They decrease the surface tension of the system and facilitate the dispersion of water in the hydrophobic resin. In addition they can aid nucleation, stabilise the foam and control cell structure. A wide range of such agents, both ionic and non-ionic, has been used at various times but the success of the one-shot process has been due in no small measure to the development of the water-soluble polyether siloxanes. These are either block or graft copolymers of a polydimethylsiloxane with a polyalkylene oxide (the latter usually an ethylene oxide-propylene oxide copolymer). Since these materials are susceptible to hydrolysis they should be used within a few days of mixing with water. 

The pendant hydroxy groups of ethylene oxide-propylene oxide copolymers of dihydroxy and trihydroxy alcohols may be sulfurized to obtain a sulfurized alcohol additive. This is effective as a lubricant in combination with oils and fats [387,533]. The sulfurized alcohols may be obtained by the reaction of sulfur with an unsaturated alcohol. Furthermore, fatty alcohols and their mixtures with carboxylic acid esters as lubricant components [1286] have been proposed. 

Unsaturations of hydroxy-containing compounds are reduced on reaction with nitrile oxides such as tetramethyl terephthalonitrile N,N -dioxide (506) or 1,3,5-triethylbenzene-2,6-dicarbonitrile oxide (507). The reaction of a nitrile oxide with terminal unsaturation, associated with the preparation of a poly-ol from propylene oxide, reduces the mono-ol content of the poly-ol composition. Thus, stirring a solution of an ethylene oxide-propylene oxide copolymer with an OH content of 2.39% and vinyl unsaturation of 3.58% in THF with l,3,5-triethylbenzene-2,6-dicarbonitrile oxide for 1 min results in an effective removal of the terminal unsaturation. 

Poly(ethylene oxide) polymers and poly(ethylene oxide/propylene oxide) copolymers with iminodipropionitrile (139) or iminodiacetonitrile end groups were used as ligands in the palladium-catalyzed oxidation of higher olefins (1-octene to 1-hexadecene) at 50-70 °C with atmospheric air or 1-3 bar O2. In an ethanol/water mixture 88 % yield of 2-hexanone and 92 % yield of 2-hexadecanone was obtained in 4 and 2 h, respectively, with a... 

Examples of the best results obtained are shown in Figure 11.21 [33,61], The composite membranes with which these data were obtained were formed by casting a solution of 80 wt% silver tetrafluoroborate in a propylene oxide copolymer matrix onto a microporous support. When subjected to a 40-day test with a gas... 

Figure 11.21 Long-term performance of a composite solid polymer electrolyte membrane consisting of 80 wt% AgBF4 dissolved in a propylene oxide copolymer matrix. Feed gas, 70 vol% ethylene/30 vol% ethane at 50 psig permeate pressure, atmospheric [33,61]...

The most common nonionic surfactants are those based on ethylene oxide, referred to as ethoxylated surfactants. Several classes can be distinguished alcohol ethoxylates, alkyl phenol ethoxylates, fatty acid ethoxylates, sorbitan ester ethoxylates, fatty amine ethoxylates, and ethylene oxide-propylene oxide copolymers (sometimes referred to as polymer surfactants). Another important class of nonionics are the multihydroxy products such as glycol esters, glycerol (and polyglycerol) esters, glucosides (and polyglucosides), and sucrose esters. Amine oxides and sulfinyl surfactants represent nonionic with a small head group. 

Tertiary oil was increased up to 41% over conventional CO2 recovery by means of mobility control where a carefully selected surfactant structure was used to form an in situ foam. Linear flow oil displacement tests were performed for both miscible and immiscible floods. Mobility control was achieved without detracting from the C02-oil interaction that enhances recovery. Surfactant selection is critical in maximizing performance. Several tests were combined for surfactant screening, included were foam tests, dynamic flow tests through a porous bed pack and oil displacement tests. Ethoxylated aliphatic alcohols, their sulfate derivatives and ethylene oxide - propylene oxide copolymers were the best performers in oil reservoir brines. One sulfonate surfactant also proved to be effective especially in low salinity injection fluid. 

Plestil, J. Pospisil, H. Sikora, A. Krakovsky, K.A.I. Small-angle neutron scattering and differential scanning calorimetry study of associative behaviour of branched poly(ethylene oxide)/poly(propylene oxide) copolymer in aqueous solution. Journal of Applied Crystallography 2003, 36, 970-975. 

Teehnol., 44, pp. 79 4 (2005)]. Another process that exploits a phase transition to facilitate separation and recycle of solvent alter extraction utilizes ethylene oxide-propylene oxide copolymers in aqueous two-phase extraction of proteins [Persson et al.,/. Chem. Teehnol. Bioteeh-nol., 74, pp. 238-243 (1999)]. After extraction, the polymer-rich extract phase is heated above its LCST to form two layers an aqueous layer containing the majority of protein and a polymer-rich layer that can be decanted and recycled to the extraction. 

Several recent patents describe the benefits of polymers in LDLDs (Table 7.15). Polymers are well known to interact with surfactants and provide many interesting properties. Some of the benefits claimed in the patents summarized in Table 7.15 are soil resistance due to amino acid copolymers, polyethylene glycol as a grease release agent, increased grease removal from polyoxyethylene diamine, enhanced foam volume and duration, increased solubility, and enhanced mildness by ethylene oxide-propylene oxide copolymers. As described in these various patents, the addition of polymers to LDLDs can aid performance in many important attributes of the product. 

The capped allyl polyalkylene oxide can also be based upon propylene oxide or a mixed ethylene oxide-propylene oxide copolymer. The resulting structure is a comb polymer, with pendant capped hydrophilic groups. In aqueous solution, the hydrophilic groups may form a sheath around the hydrophobic silicone backbone to minimize its contact with the water. 

Fig. 15. Dielectric constant vs void volume fraction for foams derived from PMDA/3FDA/ propylene oxide copolymers...

Fig. 16. Thermal stability of foams from PMDA/3FDA polyimide/propylene oxide copolymers...

Fig. 17. TEM micrograph of crosslinked polyimide foam derived from imide/propylene oxide copolymer bearing ethynyl functionality...

Other types of modifications tried include preparation of ethylene oxide-propylene oxide copolymers [129] as well as polymers containing regular sequences of oxyethylene and oxymethylene units [130]. 

Mixtures of polyethyleneglycols (and ethylene oxide-propylene oxide copolymers), a base and a peroxide (or other radical initiators) allow the preparation of several reagents which, suitably formulated according to their different use, are able to degrade the chemically stable chlorinated aromatics. Such a method, called CDP-Process, is active on TCDD and can be applied in different ways as an example, the reagent, when immobilized on a solid bed, allows the continuous-flow decontamination of mineral oils containing PCB this is useful for the decontamination of an electrical transformer during operation. Another reported example is the decontamination of surfaces contaminated by PCB or PCB fires (where PCDF and PCDD are also present). 

Ethylene oxide/propylene oxide copolymer (20.0 mol% Ethylene oxide)... 

BER Berggren, K., Johansson, H.-O., and Tjemeld, F., Effects of salts and the surface hydrophobicity of proteins on partitioning in aqueous two-phase systems containing thermoseparating ethylene oxide-propylene oxide copolymers, J. Chromatogr. A, 718, 67, 1995. 

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