Polymeric surfactants polyethylene oxide

It is, of course, possible to prepare a molecule that has both polar and nonpolar characteristics. This is the basis of surfactant chemistry. Typically, a nonpolar molecule is modified by sulfonation. The well-known Pluronic family of surfactants is based on block polymerization of polypropylene oxide (the hydrophobe) and polyethylene oxide (the hydrophUe). It is conceptually possible to build a polyurethane 2005 by CRC Press LLC... 

A detailed II NMR kinetic investigation132 of the polymerization of aniline in DC1/D20 solution has revealed no significant differences between the rates of dispersion polymerization using a polyethylene oxide)-based stabilizer and standard precipitation polymerization in the absence of any stabilizer. However, faster polymerization of aniline was observed in the presence of 20 nm silica particles, leading to PAn-silica nanocomposites. In contrast, slower polymerization occurred in the presence of surfactant micelles to form surfactant-stabilized PAn particles, presumably owing to the high solution viscosity. 

The type of emulsion stabilized by polymeric surfactants, charged or uncharged, was not investigated in detail, although it has long been understood that it was dependent of the structure of the surfactant macromolecules. In a series of papers, Riess and his coworkers [143-145] have investigated the effect of the composition and architecture of PS-PEO-based block copolymers (PS polystyrene PEO polyethylene oxide) on stability and emul-... 

The graft copolymer portion can be as low as 20% of the total system. Surfactants such as Aerosol MA-80, Aerosol OT, Emcol 4600 (sodium Tridecyl Sulfosuccinate), Surfynol 104, Igepal CO-630 (Nonylphenol polyethylene oxide) etc. can be added at the beginning of the polymerization without causing significant difference in the polymerization. Other initiators such as persulfate, benzoylperoxide etc. can also be used. 

Nanoparticles and nanocapsules resulting from the polymerization of styrene and/or divinylbenzene in miniemulsion, were produced in the presence of a polymerizable derivative of polyethylene oxide/polypropylene oxide, that was used to stabilize the droplets [54]. Subsequent X-ray photoelectron spectroscopy (XPS) measurements on dialyzed samples confirmed that the polymerizable surfactant... 

An alternative (and perhaps more efficient) polymeric surfactant is the amphipathic graft copolymer consisting of a polymeric backbone B (polystyrene or polymethylmethacrylate) and several A chains ( teeth ) such as polyethylene oxide. The graft copolymer is referred to as a comb stabilizer—the polymer forms a brush at the solid/liquid interface. The copolymer is usually prepared by grafting a macromonomer such as me-thoxy polyethylene oxide methacrylate with polymethyl methacrylate. In most cases, some polymethacrylic acid is incorporated with the polymethylmethacrylate backbone this leads to reduction of the glass transition of the backbone, which makes the chain more flexible for adsorption at the S/L interface. Typical commercially available graft copolymers are Atlox 4913 and Hypermer CG-6 (ICI). 

Accelerators are substances which increase the rate of polymerization but are not initiators in their own right. Typically, accelerators are compounded in the adhesive, and do not significantly detract from storage stability. The first accelerators described in the patent literature were polyethylene oxides of degree of polymerization (DP) greater than three, and nonionic surfactants having a polyethylene oxide moiety, also with DP greater than three. These ethers are added to the cyanoacrylate in 0.5-10% concentration. The same authors have also patented the use of crown ethers such as 18-crown-6, typically in concentrations of 10 to 1000 ppm, as polymerization accelerators. A variation on the use of crown ethers involves the combination of a substituted furan (0.1-1% concentration) (17,18) with the crown ether (0.05-0.1% concentrations). ... 

Telechelic macromers have often been used for making block copolymers. Thus the elastomic fibre, spandex (e.g. Lycra), is made from poly-THF, H(0(CH2)4) 0H, with a diisocyanate (to form a urethane), and the thermoplastic elastomer, Hytrel, is composed of blocks of poly-THF and terephthalic esters. Non-ionic surfactants are often block copolymers of polyethylene oxide/polypropylene oxide (prepared by anionic polymerization). 

The interaction between ionic polymers and nonionic surfactants has not received as much attention as the other cases discussed in the preceding sections. Much of the earlier research in this area has been focused on the interaction of anionic polymeric acids with nonionic surfactants of polyethylene oxide. The polyethylene oxide has shown the ability to form hydrogen bonds with polymeric acid like polycarboxylic acid in water. This canses a redaction in the solution viscosity as the polymer chains tend to shrink. Saito and Taniguchi (1973) studied the interaction of polyacrylic acid with a series of nonionic surfactants (EO) RE in which EO is ethylene oxide, R is hydrocarbon group, and E represents ether. They reported that the interaction in this system is a function of the nature of the hydrophobic moiety (R) and the length of the hydrophilic tail (EO). 

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