The use of microplastics in cosmetic surfactant formulations represents an increasing ecological problem. As a natural alternative the polymers examined in this work, guar gum, cationic guar gum and xanthan gum can be used as thickening agent or as stabiliser of emulsions. The rheology changed by the polymer-based gelling agent also influences the foam properties as well as the stability of the product. This is why the compatibility of several natural polymers were analysed with two different surfactant systems (anionic non-ionic surfactant system and amphoteric non-ionic surfactant system) for the specific application parameters such as the foaming behaviour, the foam stability and the foam structure and its aging. The influence of electrolytes was also analysed on the example of sodium chloride (NaCI) and then compared with the foam properties of the polymer-based gelling agent. The foam analytics was carried out using the Dynamic Foam Analyzer DFA100 (KRÜSS GmbH). In doing so, the recently released Foam Flash Method is presented and used, a method that is particularly good for the analysis of the foaming behaviour of strongly foaming surfactant solutions.
The addition of the polymer-based gelling agent to the surfactant systems had a substantial improvement to the foam formation and the foam stability, and significant influence on the foam structure. The strongest effects were shown by xanthan gum. It is also shown that the influence of individual gelling agent on the foaming behaviour depends strongly on the characteristics of the surfactant system.