ABSTRACT

Polyalcohols of sugar, imidazole ring, pyrrolidone, and pyridine are well known as typical hydrophilic groups with a ring structure [18-20]. Alkanoic esters and alkane ethers of ring-structured po1yalcohols, such as sorbitol, polysaccharides, and biosurfactants from glycolipids, are nonionic surfactants. Polyoxyethylenation of sorbitol gives a wide range of solubility and hydrophilic-lipophilic balance to the products (e.g., Span and Tween). The sorbitol esters are useful for food and pharmaceutical emulsifiers (e.g. , soluble vitamins). Alkanoic esters (C10,C!2) of polysaccharides (sugar esters) show wetting, foaming, detergency, and biodegradation properties. Alkylpolyglycosides are highly soluble in solutions of electrolytes and sodium hydroxide and do not show a cloud point. They are recommended for liquid dishwashing and hard surface cleaners. It should be mentioned [21] that the alkylpolyglycosides break down into glucose and long-chain alcohol under acidic condition, while on the alkaline side, even at very high pH, they are stable to hydrolysis. The imidazole ring shows cationic properties at low pH. These properties are discussed in the literature [18-20].