(C16-C18) and (C18) Unsaturated alkylalcohol, ethoxylate
[CAS# 68920-66-1]

Identification

• Classification: Organic raw materials >> Ether compounds and their derivatives >> Ether, ether alcohol
• Name: (C16-C18) and (C18) Unsaturated alkylalcohol, ethoxylate
• Synonyms: (E)-18-ethoxyoctadec-3-ene
• Molecular Formula: C₂₀H₄₀O
• Molecular Weight: 296.53
• CAS Registry Number: 68920-66-1 (37335-03-8)
• EC Number: 500-236-9
• SMILES: CC/C=C/CCCCCCCCCCCCCCOCC

Properties

• Solubility: 0.0004858 mg/L (25 °C water)
• Density: 0.8±0.1 g/cm³, Calc.^*
• Index of Refraction: 1.451, Calc.^*
• Melting point: 67.04 °C
• Boiling Point: 350.05 °C, 365.6±11.0 °C (760 mmHg), Calc.^*
• Flash Point: 162.4±6.8 °C, Calc.^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07;GHS05;GHS09 Danger
• Risk Statements: H302-H318-H411
• Safety Statements: P264-P264+P265-P270-P273-P280-P301+P317-P305+P354+P338-P317-P330-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Acute toxicity	Acute Tox.	4	H302
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Serious eye damage	Eye Dam.	1	H318
Eye irritation	Eye Irrit.	2	H319
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Specific target organ toxicity - single exposure	STOT SE	3	H335

Discovery and Applications

(C16-C18) and (C18) Unsaturated alkyl alcohol ethoxylates are a class of nonionic surfactants that have become essential in various industrial and household applications due to their powerful emulsifying, dispersing, and wetting properties. The development of alkyl alcohol ethoxylates began in the mid-20th century, with advancements in ethoxylation techniques that allowed for the synthesis of surfactants with varying alkyl chain lengths and degrees of ethoxylation. By reacting unsaturated fatty alcohols from natural sources like palm oil with ethylene oxide, chemists created a versatile compound family with a broad range of applications.

Ethoxylation, the chemical process used to produce these surfactants, involves adding ethylene oxide to fatty alcohols under controlled conditions, forming a hydrophilic chain of ethylene glycol groups attached to the hydrophobic alkyl chain. This balance of hydrophobic and hydrophilic parts in the molecule enhances its ability to reduce surface tension, making it highly effective in forming stable emulsions and dispersions. The length of the carbon chain (C16-C18) in these unsaturated alcohols, derived from natural fatty acids, provides them with biodegradable qualities, which are increasingly favored in environmentally conscious formulations.

In the industrial sector, (C16-C18) and (C18) unsaturated alkyl alcohol ethoxylates are commonly used in detergents, cleaning products, and emulsifiers. Their ability to remove dirt and oil from surfaces makes them indispensable in household and commercial cleaners, while their mild, non-irritating nature is valued in personal care products like shampoos, soaps, and creams. Their emulsifying and dispersing properties are also leveraged in agricultural formulations, where they help stabilize pesticide emulsions and ensure effective distribution on plants.

Another important application is in textile and paper processing, where these ethoxylates serve as wetting agents that enhance the penetration of water and other processing solutions into fibers. This results in more even dyeing in textiles and improved quality in paper products. Their usage extends to paints and coatings, where they function as dispersants that maintain the even distribution of pigments, improving color consistency and finish quality.

As these compounds are often derived from renewable sources, such as palm or coconut oil, they align with growing sustainability goals in the chemical industry. However, sourcing remains a consideration as reliance on palm oil can contribute to deforestation if not managed responsibly. Consequently, there is an ongoing push to explore sustainable sourcing and to improve the biodegradability and environmental impact of these surfactants.

The discovery and subsequent application of (C16-C18) and (C18) unsaturated alkyl alcohol ethoxylates have made significant contributions to cleaner, more efficient formulations across multiple sectors. Their versatility and environmental benefits underscore their relevance in modern product development, with ongoing research aimed at enhancing their performance and reducing environmental footprints.

References

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