Renewable Hydrophiles

Carbohydrate-based surfactants are the final result of a product concept that is based on the greatest possible use of renewable resources. While the derivatisation of fats and oils to produce a variety of different surfactants for a broad range of applications has a long tradition and is well established [1, 2], the production of surfactants based on fats and oils and carbohydrates on a bigger industrial scale is relatively new. Today the most important carbohydrate-based surfactants are alkyl polyglycosides, sorbitan esters and sucrose esters [3]. 

Natural fats and oils, carbohydrates and proteins are key raw materials for the chemical industry using renewable resources. Although in general biomass is available in large amounts (e.g. cellulose), the annual production volumes of selected bio-based 

Surfactants from Renewable Resources Edited by Mikael Kjellin and IngegSrd Johansson (c) 2010 John TOley Sons, Ltd 

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Infante MR, Perez L, Moran MC, et al. 2009b. Biocompatible surfactants from renewable hydrophiles. European Journal of Lipid Science and Technology 112(1) 110-121. 

Fine and specialty chemicals can be obtained from renewable resonrces via multi-step catalytic conversion from platform molecules obtained by fermentation. An alternative method decreasing the processing cost is to carry out one-pot catalytic conversion to final product without intermediate product recovery. This latter option is illustrated by an iimovative oxidation method developed in our laboratory to oxidize native polysaccharides to obtain valuable hydrophilic end-products useful for various technical applications. 

In the development of the protein-fatty acid condensates it was possible to combine the renewable resources fatty acids (from vegetable oil) and protein, which can be obtained from both animal waste (leather) as well as from many plants, to construct a surfactant structure with a hydrophobic (fatty acid) and a hydrophilic (protein) part (Fig. 4.12). This was carried out by reacting protein hydrolysate with fatty acid chloride under Schotten-Baumann conditions using water as solvent. Products are obtained that have an excellent skin compatibility and, additionally, a good cleaning effect (particularly on the skin) and, in combination with other surfactants, lead to an increase in performance. For instance, even small additions of the acylated protein hydrolysate improve the skin compatibility. An... 

Rubber separators have good voltage characteristics, the ability to retard antimony transfer, properties to retard dendrite growth, and good electrochemical compatibility. Due to the hydrophilic properties of the rubber composition, the separators are highly wettable and renewable for the dry-charging process. Paik et al. showed that AGE-SIL (sulfur cured, hard rubber) separators performed well in industrial stationary or traction batteries. FLEX-SIL (electron-beam-cured. flexible rubber separator) separators are suited for deep-cycling batteries, and MICROPOR-... 

As a rather strongly hydrophilic anion, nitrate requires an ISE membrane containing a strongly hydrophobic cation, as described on p. 169. This function was fulfilled in the first nitrate electrode from Orion Research by cation V [180] in nitro-p-cymene 5. The electrode can be used in the pH range 4-7. In other commercial electrodes, the ion-exchanger ion is a tetra-alkylammonium salt, for example in the electrode from Coming Co., substance XIII in solvent 6 [27]. An ISE with a renewable membrane surface was found to be very useful (see section 4.1 and fig. 4.4), in which the ion-exchanger solution contains the nitrate of crystal violet VII dissolved in nitrobenzene [191]. The NOj ISE also responds to nitrites that can be removed by addition of aminosulphonic acid. 

An alternative way to utilize renewable biomass is the so-called biomass-to-liquids (BTL) process. Parallel with GTL and CTL, BTL is essentially a variant of the F-T process that uses biomass as a feedstock. Hydrophilic zeolite membrane can also play an important role in the downstream dehydration process. 

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