Question

What are the physicochemical technical parameters of G-18 Glycerol Polyoxyethylene Ether, Polyoxyethyl Glycerol Ether?

Answer

G-18 Glycerol Polyoxyethylene Ether is a highly hydrophilic nonionic surfactant with an HLB value of up to 18. Its molecular structure consists of a glycerol backbone grafted with approximately 18 EO chain segments. It appears as a colorless to light yellow transparent viscous liquid, easily soluble in water, with excellent comprehensive performance.

Detailed Description

G-18 Glycerol Polyoxyethylene Ether (CAS No.: 31694-55-0), INCI name Glycereth-18, molecular formula C3H5(OC2H4)n(OH)3-n (n≈18), molecular weight approximately 800~900. This product is manufactured by Haian Guoli Chemical Co., Ltd., classified as a nonionic surfactant. The glycerol backbone in the molecule provides the basic hydrophilic structure, while the grafted 18 polyoxyethylene (EO) chain segments endow it with extremely high hydrophilicity and water solubility, making it an ideal choice for O/W emulsion systems.

At room temperature, the product appears as a colorless to light yellow transparent viscous liquid, with no clear melting point, and is hygroscopic. It has good chemical stability, maintaining performance within the pH range of 3~12, but may degrade under strong acids, strong bases, and strong oxidizing agents. The cloud point is greater than 100°C, indicating excellent temperature resistance and solubility in normal pressure water systems. The product is not easily flammable, with a flash point above 150°C, but thermal decomposition may produce irritating or toxic gases.

Technical Parameters

Parameter ItemTechnical Index
Product NamePolyoxyethylene (18) Glyceryl Ether / G-18 Glycerol Polyoxyethylene Ether
CAS No.31694-55-0
INCI NameGlycereth-18
AliasesGlycereth-18, PEG-18 Glyceryl Ether, Ethoxylated Glycerin (18EO), PEG-18 Glyceryl Ether
Molecular FormulaC3H5(OC2H4)n(OH)3-n, n≈18
Molecular Weight800~900
Ionic TypeNonionic
AppearanceColorless to light yellow transparent viscous liquid
HLB Value18
Active Content≥99%
Solid Content≥99%
Moisture≤0.5%
pH Value (1% aqueous solution)5.0~7.0
pH Value (5% aqueous solution)5.0~7.0
Density (25°C)1.05~1.10 g/cm³
Kinematic Viscosity100~200 mm²/s
Refractive Index1.455~1.465
Surface Tension35~40 mN/m
Critical Micelle Concentration (CMC)Approx. 0.1~1.0 g/L (25°C)
Cloud Point>100°C
Hydroxyl Value180~200 mgKOH/g
Acid Value≤0.5 mgKOH/g
Saponification Value≤2 mgKOH/g
Iodine Value≤2 gI₂/100g
Free Alcohol≤0.5%
Heavy Metals≤10 ppm
Arsenic≤2 ppm
Flash Point>150°C
Water SolubilityEasily soluble in water
HygroscopicityHygroscopic
Alkali ResistanceResistant to alkali
Chemical StabilityStable within pH 3~12, unstable under strong acids/bases/oxidizing agents
Foaming CharacteristicsRich foam, moderate stability
Penetration PowerPoor

Application Suggestions

Based on its high HLB value of 18, G-18 Glycerol Polyoxyethylene Ether is a typical O/W emulsifier, particularly suitable for formulation design in water-containing systems. In cosmetics and personal care products, it is recommended for creams, lotions, facial cleansers, makeup removers, and fragrance solubilization systems. The recommended dosage is generally 1%~5%, subject to optimization based on the specific formulation. In the textile industry, it can be used as an antistatic agent and softening finishing agent; in metalworking fluids, it provides both lubrication and rust prevention functions; in coatings and inks, it serves as an efficient wetting and dispersing agent, offering excellent dispersion stability for pigments and fillers.

Since the product is easily soluble in water and hygroscopic, it should be used promptly after opening and stored sealed. When compounding, it is compatible with anionic, cationic, and other nonionic surfactants, offering broad applicability.

Precautions

  • Skin and Eye Irritation: GHS classification: Skin irritation (H315) and Serious eye irritation (H319). Wear protective gloves and goggles during handling to avoid direct contact.
  • Storage Requirements: Store in a cool, dry, well-ventilated warehouse at a recommended temperature of 5~30°C. Avoid freezing and high temperatures, and keep the container tightly sealed.
  • Incompatible Substances: Store separately from strong oxidizing agents, strong acids, and strong bases to avoid contact leading to product degradation.
  • First Aid Measures: In case of eye contact, immediately rinse with plenty of water for at least 15 minutes and seek medical attention. For skin contact, wash thoroughly with soap and water. If inhaled, move to fresh air. If ingested, do not induce vomiting; immediately rinse mouth and drink plenty of water, then seek medical attention.
  • Packaging Specifications: Available in 50kg plastic drums, 200kg plastic drums, and 1000kg IBC totes. Data source: Guoli Chemical Product Database.