Diethylhexyl carbonate  is a chemical compound, carbonic acid ester of hexanol, an organic alcohol.

The name of this compound provides information about its structure and components:

• Di-  indicates that there are two identical groups in the compound.
• Ethylhexyl refers to the 2-Ethylhexyl group, which is a branched chain of eight carbon atoms (C₈H₁₇-).
• Carbonate indicates that the compound is an ester of carbonic acid. Carbonates are compounds that contain a carbonate group (CO₃), but in the case of esters such as Diethylhexyl carbonate, the carbonate group is modified to -O-C(=O)-O-.

The synthesis process takes place in different steps:

• The reaction begins with the conversion of greenhouse gas CO₂ and petroleum-derived alkylene oxide into high-value carbonate substances. This is considered a green and economic path for carbon reduction and energy transition.
• The catalyst used in this process is a multi-porous calcium aluminum hydrotalcite material (Ca-Al HT). This catalyst has excellent catalytic ability on transesterification, an important reaction in the synthesis of carbonates.
• The robust Ca₁₂Al₁₄O₃₃ crystal phase in the Ca-Al HT catalyst provides stable catalytic performance during the long-term catalytic process.
• The outstanding catalytic ability of Ca-Al HT is attributed to its super-strong alkali strength, large alkali amount, and quick mass transfer originating from the hierarchical pore system1.
• Another method involves using CO₂ and methanol as raw materials to produce dimethyl carbonate (DMC), which is then used to produce diethylhexyl carbonate.
• The DMC production rate is strongly enhanced with increasing concentration of oxygen vacancies.
• The reaction of a bidentate carbonate intermediate with the activated methoxy (-OCH₃) species is identified as the highest energy barrier in the reaction pathway and is likely the rate-determining step.

It appears as a clear liquid with a characteristic odour, poorly soluble in polar solvents such as alcohols and acids, but is more soluble in non-polar organic solvents.

What it is used for and where

Cosmetics

• Skin conditioning agent. It is the mainstay of topical skin treatment as it has the function of restoring, increasing or improving skin tolerance to external factors, including melanocyte tolerance. The most important function of the conditioning agent is to prevent skin dehydration, but the subject is rather complex and involves emollients and humectants that can be added in the formulation.
• Skin conditioning agent - Emollient. Emollients have the characteristic of enhancing the skin barrier through a source of exogenous lipids that adhere to the skin, improving barrier properties by filling gaps in intercorneocyte clusters to improve hydration while protecting against inflammation. In practice, they have the ability to create a barrier that prevents transepidermal water loss.  Emollients are described as degreasing or refreshing additives that improve the lipid content of the upper layers of the skin by preventing degreasing and drying of the skin. The problem with emollients is that many have a strong lipophilic character and are identified as occlusive ingredients; they are oily and fatty materials that remain on the skin surface and reduce transepidermal water loss. In cosmetics, emollients and moisturisers are often considered synonymous with humectants and occlusives.

Diethylhexyl carbonate  is a liquid also used for make-up removal with a non-oily emollient action on the skin. It also has a protective film-forming action on the skin that improves the spreadability of the cream.

Appearance	Transparent liquid
Boiling Point	342.6ºC at 760mmHg
Flash Point	131.3ºC
Density	0.895g/cm3
PSA	35.53000
LogP	5.57240
Vapour Pressure	7.44E-05mmHg at 25°C
Refraction Index	1.439
Safety

• Molecular Formula  C₁₇H₃₄O₃
• Molecular Weight     286.4
• Exact Mass   286.25100
• CAS  14858-73-2
• UNII    YCD50O0Z6L
• EC Number   238-925-9
• DSSTox Substance ID  DTXSID60864544
• IUPAC  bis(2-ethylhexyl) carbonate
• InChI=1S/C17H34O3/c1-5-9-11-15(7-3)13-19-17(18)20-14-16(8-4)12-10-6-2/h15-16H,5-14H2,1-4H3  
• InChl Key    PXTQQOLKZBLYDY-UHFFFAOYSA-N  
• SMILES   CCCCC(CC)COC(=O)OCC(CC)CCCC
• MDL number  
• PubChem Substance ID    
• RXCUI      1307048  

Synonyms

• bis(2-ethylhexyl) carbonate
• Carbonic acid, bis(2-ethylhexyl) ester

References_____________________________________________________________________

Heunemann, P., Prévost, S., Grillo, I., Marino, C. M., Meyer, J., & Gradzielski, M. (2011). Formation and structure of slightly anionically charged nanoemulsions obtained by the phase inversion concentration (PIC) method. Soft Matter, 7(12), 5697-5710.

Zhang, F., Liao, P., Sun, Y., Chen, Z., Pang, Y., & Huang, Y. (2020). Surfactant and oil formulations for monodisperse droplet emulsion PCR. Lab on a Chip, 20(13), 2328-2333.

Chevalier, Yves, and Marie-Alexandrine Bolzinger. "Micelles and nanoemulsions." Nanocosmetics: From Ideas to Products (2019): 47-72.