Alkyl polyglycosides specifications

Most alkyl polyglycoside containing consumer products, such as detergents, cleaners, etc., enter wastewater or the environment after use. A series of tests can be carried out to ensure environmental safety (Table 1) [37]. Substance-specific analytical methods have been developed for this purpose. Those... 

In the Fischer glycosidation, the reaction parameters temperature and pressure are closely related. To produce an alkyl polyglycoside low in secondary products, pressure and temperature have to be adapted to one another and carefully controlled. Low reaction temperatures (<100°C) in the acetalization lead to aUcyl polyglycosides low in secondary products. However, low temperatures result in relatively long reaction times (depending on the chain length of the alcohol) and low specific reactor efficiencies. 

After the reaction, the acidic catalyst is neutralized by a suitable base, for example sodium hydroxide or magnesium oxide. The neutralized reaction mixture is a yellowish solution containing 50 to 80 % fatty alcohol. The high fatty-alcohol content results from the molar ratios of carbohydrate to fatty alcohol. This ratio is adjusted to obtain a specific DP for the technical alkyl polyglycosides and is generally between 1 2 and 1 6. The excess fatty alcohol is removed by vacuum distillation. Important boundary conditions include ... 

Addition of alkyl polyglycosides modifies the rheology of concentrated surfactant mixtures so that pumpable, preservative-free, and readily dilutable concentrates containing up to 60% active substance can be prepared. These concentrated blends of several components may be generally used as cosmetic raw materials or specifically as core concentrates in the production of cosmetic formulations (for shampoos, shampoo concentrates, foam baths, shower gels, etc.). 

Microemulsions can be obtained in different ways. For ethoxylated nonionic emulsifiers the temperature is the decisive parameter therefore, the micro-emulsion phase is stable only in a certain limited temperature range. If other specific types of surfactants are used, e.g., alkyl polyglycosides, the temperature dependence is less pronoimced or even negligible. In this case, the formation of microemulsions is enabled by adjusting a specific mixing ratio of different emulsifiers, i.e., balancing the hydrophilic to lipophilic components in the surfactant system. 

FIG. 5 Electrical conductivity and transparency of a model emulsion comprising C 2/i4 alkyl polyglycoside, glyceryl monooleate (GMO), and a specific amount of water and dioctylcyclohexane at 25 C with varying emulsifier mixture ratios. The dashed line separates the w/o from the o/w region [10]. 

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