INGREDIENTS
Select the perfect silicone for your formulation Silicone chemistry plays an important role in modern personal care and cosmetics products, delivering superior aesthetics and unmatched, cost-effective sensory benefits. By selecting the right silicone for your formulation, experts at BRB Silicones say you can easily meet the most demanding consumer requirements. creams, lotions, sunscreens, bath oils and hair care products. High viscosity dimethicones (60 000 to 100 000 cSt) are commonly used in hair care products. Dimethiconol, also referred to as silicone gum, is a polymer similar to dimethicone where two chain-end methyl groups have been replaced by hydroxyl (-OH) groups. Dimethiconol is widely used in hair cuticle coat formulations (see Table 1), offering a remedy for split-ends.
Silicone surfactants These are synthesised to contain both silicone and water-soluble groups within the same molecule. The result is a series of compounds with varying and controllable levels of solubility in oil, water
V
and silicone. A common silicone surfactant is olatile silicone fluids consist of cyclic and linear molecules with a viscosity of less than 5 cSt. The term cyclomethicone refers to a series of
cyclic silicone compounds. Cyclomethicone with low heat of vaporisation and low viscosity imparts a transient, non-greasy and non-cooling effect on skin. It helps improve the rub-in and spreadability of creams and lotions. Cyclomethicone can be used alone or blended with other cosmetics fluids to provide a liquid base for a variety of ingredients. It features good solubility in most anhydrous alcohols and in many solvents. Dimethicone is the INCI name for a series of basic linear silicones used as base fluids. These inert polymers are optically clear, odourless and non-flammable. They are often referred to as silicone oil, dimethyl polysiloxane and polydimethylsiloxane, and take viscosities within a broad range from 5 to 1 000 000 cSt. Dimethicones with low (5 to 50 cSt) and medium viscosity (50 to 1000 cSt) are widely used in
A
of water-in-silicone or silicone-in-water emulsions. There are various types on the market, offering an array of HLB values (see Table 2). Cyclopentasiloxane (and) PEG/ PPG-18/18 Dimethicone is one type of dimethicone copolyol widely used to prepare water-in-silicone emulsions commonly found in antiperspirant, skin care and colour cosmetics formulations. The material’s low surface tension and effective wetting properties provide a unique and gentle skin-feel whilst stabilising the emulsion. PEG/PPG Dimethicone is used as an emulsifier in the preparation of water-in-oil and siliconein-water emulsions. It can be used to prepare products with a low concentration of wax and high concentration of water, offering creams and lotions with a light and easily spreadable skin feel. A high surface activity offers other advantages compared to conventional w/o emulsifiers. PEG/PPG Dimethicone should be added and mixed into the silicone or oil phase in the
INCI
Dosage (%)
emulsion. Electrolytes such as sodium chloride
Cyclopentasiloxane (and) Dimethiconol
60.00
should be pre-dissolved into the water phase to
Cyclopentasiloxane
40.00
viscosify and help develop a stable emulsion. Add
In this hair cuticle formulation, the volatile cyclopentasiloxane functions as a temporary, transient conditioner, while the non-volatile dimethiconol offers gloss-enhancing benefits
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compound designed to assist in the preparation
preparation of a silicone-in-water or water-in-oil
Table 1: Silky Hair Cuticle Coat
Phase
dimethicone copolyol. This is an amphiphilic
| JUNE 2018 | P C Review
the water phase slowly into silicone or oil phase to ensure complete and uniform emulsification.