Properties aqueous cleaners

Table 7.8. Physical properties of assorted aqueous cleaners.

Water-miscible semi-aqueous cleaners include low molecular weight alcohols, ketones, esters, and organic amines. Table 13.4 gives some properties of water-miscible cleaners. N-methyl-2-pyrrolidone-based solvents have a high solvency for a number of contaminants and are completely water-soluble. Acetone (CH3COCH3) removes heavy oils quite effectively hut tends to leave a residue and it is also quite flammable. Acetone cleaning or wipeclean should be followed by a methanol rinse or wipeclean to remove the residue. 

Because of these unique properties, xanthan gum has utility in a wide range of applications. In the petroleum area, xanthan gum is used to thicken oil-well drilling fluids and to provide viscous aqueous solutions for enhanced oil recovery. In the industrial area, xanthan gum finds utility in thickening textile printing pastes, acid and alkaline cleaners, slurry explosive formulations, and in a wide range of other industrial applications. 

Keeping in mind the importance of chitosan, as well as its economic value as an industrial product, we must pay attention to its key physical parameter, i.e., turbidity. Depending on source, a marked difference is observed in aqueous solutions of chitosan and its derivatives in terms of their turbidity [33]. Turbid aqueous solutions of chitosan and chitosan-derived products greatly lose their commercial value. Such chitosan cannot be used as a commercial product and in some cases may have to be discarded. Therefore, the selection of source plays a pivotal role in the production of chitin and chitosan. Shepherd et al. [20] reported the production of chitosan from New Zealand Arrow squid Notodarus sloani) pens as well as the evaluation of the functional properties of this squid chitosan compared with chitosan extracted from crustacean sources. Squid pen chitin and chitosan were visibly cleaner than chitin and chitosan obtained from crab and crayfish. In addition, due to the lower mineral content of squid pen as compared to cmstacean shells, the demineralization process can be skipped to extract chitin, which also makes the production cheaper. As shown in Table 4, the squid pen chitosan is similar in... 

The primary use of a-pinene, and therefore of turpentine, involves the hydration by aqueous mineral acids to synthetic pine oil, the primary constituent of which is a-terpineol (Fig. 10.1.7). Between 40% and 50% of the world turpentine production is so used. Good emulsifiers are needed in the hydration reaction because the hydration takes place at the a-pinene-aqueous acid interface. Variations in reaction conditions, fractionation, and blending give pine oils with different compositions and properties. Over 90% of the US. pine oil is used in cleaner and disinfectant formulations because the piney odor is pleasant and because pine oil is a good emulsifier, an excellent solvent, and an effective germicide of low toxicity. 

---