Study of formulation and stability of emulsions with polymeric emulsifiers

Polymeric emulsifiers have appeared recently and have got emulsifying and t hickness properties. These emulsifiers provide exceptional stability to oil -in-water-emulsions. This study shows formulations of new emulsifiers. The polymeric emulsifiers used were acrylate C-10-C-30 alkyl-acrylate cross pol ymer (T-r1-T-r2). They provide exceptional stability to oil-in-water emulsi ons at very low usage levels (0.1, 0.3%), they can be used with any oil pha se, easily prepared without heat with liquids ingredients. They can be used with any oil phase. Easily prepared without heat with Liquids ingredients, they resist at different pH and they provide unique aesthetic qualities on the skin. A study of film-forming polymers was realized with Mallinckrodt dynometer at room temperature by the classical method of the tearing of the ring (Norm NF ISO 304). It showed the elasticity of surface-film and the r etreat of the extensibility limit which increases proportionally with the c oncentration. In the same time, the tensioactive power is low (T-s of solut ion at 10(-4) g l(-1) 59.9 to 61.6 mN m(-1)). The formulations were made wi th many oil types like vegetal oils, synthetical ester oils. This study sho wed that these thickening emulsifiers cannot emulsify different oil types w ithout a coemulsifier. Non ionic surfactants from natural origin like sucro esters (sucrose mono and distearate, sucrose palmitate) permitted a good em ulsification at room temperature, with all kind of oil except mineral oil. Mineral oil permit a good emulsification at room temperature, with all kind s of oil except mineral oil. Mineral oils are more compatible with coemulsi fiers like polyoxyethylated sorbitan ester and sorbitan ester. In any case, it is necessary to use HLB values between 10 and 14, to be in synergy with polymeric derivatives which have a large hydropilic portion and a small li pohilic portion. The addition of thickener of same type improves stability. The stability was controlled at room temperature and at 37 degrees C by cl assical methods: rheological analysis, microscopical observation and pH mea surements. This type of polymeric emulsifiers gives good results without he ating if it is dispersed in the oily phase and used with a coemulsifier. (C ) 1999 Elsevier Science B.V. All rights reserved.