Читать книгу Surface Science and Adhesion in Cosmetics - Группа авторов - Страница 55

Due to increasing consumer demand for natural cosmetic products, environmental awareness and new regulations in beauty industry, the natural waxes and natural oils have been developed and have replaced the synthetic ones in cosmetic products. In order to achieve the same performance as the non-natural/synthetic products, the understanding of the crystallization of the natural waxes with oils and pigments/fillers is necessary. By using the simplest model containing a non-polar PE wax and various polar oils, we showed that the hardness of the lipstick was affected by both the oil polarity and oil viscosity at a fixed amount of wax. Increasing the oil polarity and viscosity, the oil-wax stick was harder with smaller or close-packed crystals as observed by SEM. These results were found to be very similar to the natural wax-oil gel systems reported in literature. In addition, increasing the oil viscosity, the sensorial perception was observed to change from smooth to watery to sticky, and it did not depend on the oil polarity. From this simple oil-wax model, we can apply these results to modulate the hardness of natural lipstick, its deposit and sensorial perception by selecting the right oil and the right amount of any wax in the formulation.

However, the next challenge for cosmetic scientists is how to reformulate the long-wear, non-transfer cosmetic products using natural film-formers, natural oils, natural color pigments/fillers and natural waxes to achieve the same performance results as the silicone based products.