Polyethylene carboxylic acid

Ferguson, G., Whitesides, G. Thermal reconstruction of the functionalized interface of polyethylene carboxylic acid and its derivatives. In Schrader, M., Loeb, G. (eds.) Modem Approaches to Wettability, pp. 143-177. Springer, New York (1992)... 

Wilson, M. D. Whitesides, G. M. The anthranilate amide of polyethylene carboxylic-acid shows an exceptionally large change with Ph in its wettability by water. J. Am. Chem. Soc. 1988,110, 8718-8719. 

Sorbitan esters of fatty acids are well known. Similar products can be made from ether carboxylic acids and sorbitol without an acid catalyst with a good color [39]. The advantage of these products is that the hydrophilicity can be adjusted by the polyethylene glycol content in the ether carboxylic acid. 

For an analogous reaction of ferrocene carboxylic acid with polyethylene glycol) see reference [172]. 

Here the polymer grows by successive esterification with elimination of water and no termination step. Polymers formed by linking monomers with carboxylic acid groups and those that have alcohol groups are known as polyesters. Polymers of this type are widely used for the manufacture of artificial fibers. For example, the esterification of terephthalic acid with ethylene glycol produces polyethylene terephthalate. 

In addition to the natural waxes, a number of synthetic waxes were analysed with GALDI-MS carboxylic acids (Hoechst wax-L, -S), esters (Hoechst wax-FL, -H, -O), and glycol esters (Hoechst wax-KP, -KPS). In most cases, significant mass spectra were obtained. The mass spectrum of polyethylene glycol (Carbowax 6000) showed a series of signals the spacing of m/z 44 between the signals corresponds to one oxyethylene unit. 

Oxidation is the first step for producing molecules with a very wide range of functional groups because oxygenated compounds are precursors to many other products. For example, alcohols may be converted to ethers, esters, alkenes, and, via nucleophilic substitution, to halogenated or amine products. Ketones and aldehydes may be used in condensation reactions to form new C-C double bonds, epoxides may be ring opened to form diols and polymers, and, finally, carboxylic acids are routinely converted to esters, amides, acid chlorides and acid anhydrides. Oxidation reactions are some of the largest scale industrial processes in synthetic chemistry, and the production of alcohols, ketones, aldehydes, epoxides and carboxylic acids is performed on a mammoth scale. For example, world production of ethylene oxide is estimated at 58 million tonnes, 2 million tonnes of adipic acid are made, mainly as a precursor in the synthesis of nylons, and 8 million tonnes of terephthalic acid are produced each year, mainly for the production of polyethylene terephthalate) [1]. 

As with fullerenes, carbon nanotubes are also hydrophobic and must be made soluble for suspension in aqueous media. Nanotubes are commonly functionalized to make them water soluble although they can also be non-covalently wrapped with polymers, polysaccharides, surfactants, and DNA to aid in solubilization (Casey et al., 2005 Kam et al., 2005 Sinani et al., 2005 Torti et al., 2007). Functionalization usually begins by formation of carboxylic acid groups on the exterior of the nanotubes by oxidative treatments such as sonication in acids, followed by secondary chemical reactions to attach functional molecules to the carboxyl groups. For example, polyethylene glycol has been attached to SWNT to aid in solubility (Zhao et al., 2005). DNA has also been added onto SWNT for efficient delivery into cells (Kam et al., 2005). 

Before we turn to "mechanisms" let us repeat how a catalyst works. We can reflux carboxylic acids and alcohols and nothing happens until we add traces of mineral acid that catalyse esterification. We can store ethene in cylinders for ages (until the cylinders have rusted away) without the formation of polyethylene, although the formation of the latter is exothermic by more than 80 kjoule/mol. We can heat methanol and carbon monoxide at 250 °C and 600 bar without acetic acid being formed. After we have added the catalyst the desired products are obtained at a high rate. 

Laboratory studies carried out by Priest and his co-workers - have demonstrated by means of infrared and other techniques that terminal double bonds in polyethylene end groups are attacked by "ozonized" oxygen to form carboxylic acid groups and by rupture of... 

Preparation of inclusion complex of polyethylene glycol-carboxylic acid and a-cyclodextrin... 

Polyoxyethylene Esters, This series of surfactants consists of polyoxyethylene (polyethylene glycol) esters of fatty acids and aliphatic carboxylic acids related to abietic acid (see Resins, natural). They differ markedly from mono- and diglycerides in properties and uses. 

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