Study on the transferability of the time temperature superposition principle to emulsions.
The instability of emulsions is basically clarified by a phase separation. The separated phase can either cream or sediment. Destabilization is mostly compounded by coalescence and gives a first indication through extension of droplets. In the cosmetics industry as well as many other branches of industry such as the food industry and paint and coatings industry, product stability is one of the most important quality criteria. Many stability tests have already been performed with the widest variety of methods from different fields of technology. In research and development it is especially important to obtain quick results on the stability of a formulation. Such results represent a tool that can help developers find an optimal formulation in a short time. In addition, they can shorten development times, leading to quicker introduction of a product in the market. Moreover, they can help to reduce storage stability tests to minimum, making less climatized rooms, space and work required to predict shelf-lives. The cycle test is an example of such a method developed in the field of rheology [1]. In this test the sample is subjected to continuously changing temperatures and its behavior observed. However, other methods can also conceivably used to predict stabilities. The aim of this work is to find a new model to predict the long-term stability. This model should be based on empirical data and it should determine the applicability of the time temperature superposition (TTS) principle to emulsions.
Muehlbach
M
M
Department of Rheology/Thermal Analysis, Beiersdorf AG, 20253 Hamburg, Germany.
Brummer
R
R
Eggers
R
R