2-Ethylhexyl 4-(dimethylamino)benzoate is a lipophilic ester obtained from 4-dimethylaminobenzoic acid and 2-ethylhexanol. The molecule exhibits strong UV-A absorption (λmax ≈ 311 nm, ε ≈ 2.7×10⁴ L mol⁻¹ cm⁻¹) and is miscible with common cosmetic oils, fatty alcohols and ethanol, while being practically insoluble in water (< 0.5 g L⁻¹ at 25 °C). It functions as an efficient oil-soluble UV filter and as a co-initiator synergist in UV-curable nail gels and dental resins. Commercial material is supplied at ≥ 98 % purity and remains stable for ≥ 2 years when stored at room temperature in tightly closed containers away from light.
Key Physicochemical Data:
Density: 0.990–1.000 g cm⁻³ (25 °C)
Refractive index: n²⁵/D 1.539–1.543
Boiling point: 382.9 ± 25 °C at 760 mmHg (predicted)
Flash point: 121.7 ± 14 °C (closed cup, predicted)
Log P (octanol/water): 6.15 (predicted)
Acid value: ≤ 1.0 mg KOH g⁻¹
Typical Uses:
Primary UV-A filter in broad-spectrum sun-care formulations (EU, US, ASEAN) and daily-use cosmetics.
Co-initiator/synergist for UV-curable nail gels, dental resins and cosmetic coatings.
Building block for lipophilic UV-absorbing polymers and micro-capsule wall materials.
Quality Specification (Commercial Grade):
Purity (HPLC): 97.0–102 %
Water content (KF): ≤ 0.3 %
Individual impurity (GC): ≤ 0.5 %
Total impurities (GC): ≤ 2.0 %
Heavy metals: ≤ 20 ppm
Hazard Statement:
Causes skin and eye irritation (H315 + H319). Avoid inhalation of vapour; use gloves, goggles and adequate ventilation. Store in a cool, dry place away from oxidants and strong acids. SDS available on request.
