Croda has added a rheology modifier to its ViscOptima range that can emulsify and stabilize high levels of oils and silicones in a formulation. ViscOptima SE (INCI: Sodium Polyacrylate (and) Ethylhexyl Cocoate (and) PPG-3 Benzyl Ether Myristate (and) Polysorbate 20) is an efficient thickener that can create viscous creams at low inclusion levels to leave a smooth, silky, silicone-like feel to the skin.
The anionic rheology modifier thickens up to 65,000 cPs at 2%, auto-emulsifies up to 30% oil or silicone and adds smooth, silky and dry aesthetics to a formulation through the use of Crodamol STS emollient ester technology.
The rheology modifier is a polyacrylate polymer dispersed in a carrier oil containing an inverting surfactant. Upon addition to water, it inverts to form an o/w emulsion, allowing the polyacrylate molecules to swell by osmosis and consequently thicken the water phase. it thickens immediately when added to water, creating a viscous cream. At low polymer concentration, the swollen polyacrylate matrix creates a low viscosity, flowable lotion. At 1%, the swollen polyacrylate reaches optimum swelling, creating a viscous cream. At concentrations above 1%, the viscosity of the cream does not increase significantly.
The rheology modifier boasts shear thinning rheology and is non-thixotropic. This results in the reduction in viscosity when force is applied to the formulation, such as pumping or spraying, and immediate recover of the viscosity when the force is no longer applied. This is a particular benefit when particles are suspended in the formulation.
The rheology modifier can be incorporated at any time during formulation including post addition. It is cold and hot processable. It is recommended at 0.5-3.0% in facial creams, body cream, eye cream, moisturizing cream and moisturizing lotion. It has temperature and freeze-thaw stability.