Polyglyceryl-2 Diisostearate (Emulsifier)

Polyglyceryl-2 Diisostearate – Non-Ionic Diester Emulsifier for Stable Emulsions and Enhanced Texture

Basic Information

• INCI Name: Polyglyceryl-2 Diisostearate

• CAS Number: 70445-52-2 (general for polyglyceryl isostearates; specific grade may vary)

• Synonyms: Diglyceryl diisostearate, Polyglycerol-2 diisostearate, PG-2 Diisostearate

• Appearance: Pale yellow to amber viscous liquid or waxy solid

• HLB Value: Low (lipophilic, suitable for W/O and O/W emulsions)

• Solubility: Soluble in oils and organic solvents; dispersible in water

• Storage: Store in tightly sealed containers in a cool, dry place, protected from light and moisture

Overview
Polyglyceryl-2 diisostearate is a non-ionic diester produced by the esterification of polyglycerin-2 (diglycerin) with two molecules of isostearic acid. This diesterification introduces two lipophilic isostearyl chains while retaining one free hydroxyl group from the diglycerin backbone, providing a balanced hydrophilic-lipophilic profile. The compound effectively reduces interfacial tension, stabilizes both water-in-oil (W/O) and oil-in-water (O/W) emulsions, and provides excellent skin conditioning and texture improvement. It is mild, biocompatible, and biodegradable, derived from renewable plant-based sources.

Chemical Structure and Synthesis
The synthesis can be represented by the following equation:
PG₂ + 2 Isostearic Acid → Polyglyceryl-2 Diisostearate + 2 H₂O
where PG₂ denotes polyglycerin-2 (diglycerin). Two substituted hydroxyl groups add lipophilic character, while the remaining non-esterified –OH group retains hydrophilicity.

Key Properties

• Non-ionic – compatible with a wide range of ingredients and pH levels.

• Amphiphilic – reduces interfacial tension, stabilizing both O/W and W/O emulsions.

• Enhanced lipophilicity – suitable for oil-rich and emollient formulations.

• Good skin compatibility and mildness – suitable for sensitive skin.

• Excellent thermal and chemical stability.

• Rheological improvement – enhances flow and consistency of emulsion systems.

• Biocompatible and low toxicity – safe for topical applications.

• Biodegradable and derived from renewable plant-based sources.

• Provides smooth, velvety textures and enhances skin feel.

Applications

• Cosmetics and personal care: Used as a primary or co-emulsifier in W/O and O/W creams, lotions, serums, sunscreens, makeup removers, and hair care products. Provides stable, elegant textures with good spreadability, moisturizing properties, and emollient benefits.

• Pharmaceuticals: Employed as an emulsifier, solubilizer, and penetration enhancer in topical ointments, creams, and suppositories.

• Lubricants: Applied to optimize rheological characteristics and provide stable coating structures.

• Industrial: Used as a dispersant, lubricant, and stabilizer in specialty chemical formulations.

Key Benefits

• Effective emulsification for both O/W and W/O systems.

• Mild and non-irritating – suitable for sensitive skin and baby products.

• Emollient properties – softens and conditions skin and hair.

• Excellent thermal and chemical stability.

• Rheological improvement – enhances flow and consistency.

• Biocompatible, biodegradable, and of natural origin.

• Compatible with a wide range of cosmetic, pharmaceutical, and industrial ingredients.

• Acts as a co-emulsifier, thickener, and stabilizer in complex formulations.

Recommended Use
Typical usage levels range from 1–5% of the formulation, depending on the desired emulsion stability, viscosity, and texture. For optimal performance, dissolve in the oil phase at elevated temperatures (60–70°C) before emulsification. Can be combined with co-emulsifiers and thickeners for tailored rheology.

Safety and Handling

• Generally recognized as safe for use in cosmetics and personal care at recommended concentrations.

• Low irritation potential; well-tolerated by skin and mucous membranes.

• Avoid contact with strong oxidizers and acids.

• Store in a cool, dry place, away from direct sunlight.

• Use appropriate personal protective equipment (gloves, safety goggles) when handling.

Quality Assurance
Each batch is tested for acid value, saponification value, and emulsification performance to ensure consistent quality.