When choosing a surfactant for a particular use, it is imperative to understand how a surfactant’s molecular structure governs its physical and application properties. As all surfactants contain a hydrophilic ‘head’ that is covalently bound to a hydrophobic ‘tail’, one can envision the endless possibilities of physical attributes by combining these two critical components of surfactant’s molecular architecture in a variety of manners. Sulfates, phosphates and ethoxylated nonionics are just a few of the hydrophilic components that are at the disposal of surfactant engineers.
On the other hand, a vast amount of hydrophobic carbon chains exist for the surfactant chemist, including linear, branched, aryl, short- and longer-chain alkyl groups. Surfactant chemical companies have a vast toolbox of surfactant compounds that are designed to fill the needs of every industry, and must combine a keen understanding of the surfactant’s architecture with a specific product’s application goals.
A unique set of surfactants within this ‘molecular-toolbox’ are the long-chain alcohol ethoxylates (C16-C18). This distinct class of molecules utilizes various lengths and distributions of the hydrophobic carbon chain to tune certain physical properties to meet the needs of the commercial market. These longer chain alkyl groups are sourced from bio-renewable materials, most notably the oil from palm kernel, making them an eco-friendly and biodegradable option for emulsification, cleaning agents and cosmetic applications. These longer hydrophobic chains can be used to alter the viscosity of formulations, the emulsification of fats and the solubilization of oils, making them effective additives for the coating’s market.
Oxiteno’s line of long-chain alcohol ethoxylates, including cetyl (ALOKANT® O series), cetearyl (ALKONAT® CE series), cetoleyl (ALKONAT® OC series) and stearyl (ALKONAT® E series) alcohol ethoxylates have all been designed to meet the stringent demands of the personal- and home-care markets. Each product acts as a powerful additive for the formulator, as their emulsifying strengths (HLB) range from 4.9-to-18.6 and their viscosities can be tuned to meet the needs of personal care industry.
While these products are robust additives, when used in combination with one another, their ability to emulsify oils and form stable colloidal dispersions are enhanced.1 Due to their high compatibility with other nonionic-, cationic- and anionic-surfactants, these longer-chain alcohol ethoxylates will allow the formulator to obtain the optimal balance between performance and cost for the application of their final product. More information regarding these products’ properties, applications and regulations can be found by viewing Oxiteno’s Personal Care webpage or by contacting Oxiteno’s talented team of home and personal care formulation chemists.
One of the most useful segments for these types of compounds is the personal care and cosmetic industries. The large number of carbons associated with cetyl- and stearyl- alcohol ethoxylates make them excellent emollients for skin care, meaning they are superb at softening and moisturizing the skin’s surface. Due to their long fatty carbon chain, they are more effective at forming an oily layer atop the skin’s surface as compared to shorter alkyl chain ethoxylates. While the fatty carbon portion of the ethoxylate is busy forming the oily-layer, the hydrophilic portion of these alcohol ethoxylates plays the critical role which holds water close to the skin’s surface, allowing the epithelial cells to absorb more of it. The unique combination of hydrophilic polyoxyethylene portion with the long-chain hydrophobic tail creates an ideal situation that essentially traps water within the skin, leading to a moisturizing effect that leaves the skin feeling smooth and hydrated.
In addition to the emollient properties of these alcohol ethoxylates, they are additionally used to solubilize fats, emulsify oils and alter the viscosity of many other personal care products, such as lotions and creams. The increased number of carbons along the hydrophobic section of these nonionic surfactants allows them to hold on tightly to oils and fats, making them efficient at dispersing hydrophobic oily materials into aqueous systems. This property makes these types of surfactants excellent emulsifiers for the preparation of stable cosmetic formulas and efficient at solubilizing unwanted hydrophobic materials into water (i.e. detergents).
The mildness associated with longer chain alcohol ethoxylates lends themselves to their extensive use in the skin and personal care segments, as many of these long-chain alcohol ethoxylates have been determined to be safe for use in cosmetics by the Cosmetic Ingredient Review.2-4 Additionally, Oxiteno sources all of its long-chain alcohol products from renewable, natural resources, making our line of long-chain alcohol ethoxylates an ecofriendly alternative for the formulations chemist. Information on raw materials sourcing and bio-based carbon content5 can be obtained by contacting Oxiteno’s R&D and Regulatory team here.
Oxiteno is one of the industrial leaders that specializes in making long-chain alcohol ethoxylates throughout the Americas. The ALKONAT® C, CE, OC and E series will all be produced in Oxiteno’s new state of the art production facility, located in Pasadena, TX, which is equipped with a 25 and 40 MT ethoxylation unit and can produce up to 170 KT per year. Being strategically placed in the US Gulf, this site allows for easy access to raw materials and logistics, all while being designed to withstand the ever-present hurricane prone environment of the Gulf of Mexico. Additionally, Oxiteno’s R&D facilities, located in Hattiesburg, MS, have the capabilities to prepare sample formulations and customize products for our clients. The R&D center is well equipped to take a customer’s concept, prepare samples for approval and rapidly transfer the technology into the industrial scale at Oxiteno’s industrial manufacturing site. The ability to manufacture these products to conform to the necessary regulations to ensure a safe product that has minimal impact on the environment requires a company that has the manufacturing capabilities and correct mindset to safely engineer these compounds.
Oxiteno recognizes that having the global infrastructure is not enough to ensure the sustainability and well-being of our planet, which is why the people of Oxiteno are committed to making safer, more environmentally friendly products for all markets served. Industrial collaboration is a key component to the production of effective and environmentally safe surfactants. Please feel free to contact Oxiteno’s staff scientists and marketing researchers to help develop ideas and foster environmentally-conscience collaborations.
1- Nace, Vaughn. Nonionic surfactants: polyoxyalkylene block copolymers. Vol. 60. CRC Press, 1996.
2-CIR (Cosmetic Ingredient Review). 2006. CIR Compendium, containing abstracts, discussions, and conclusions of CIR cosmetic ingredient safety assessments. Washington DC.
3- Elder, R. L. “Final report on the safety assessment of Steareth-2,-4,-6,-7,-10,-11,-13,-15, and-20.” Journal of the American College of Toxicology 7.6 (1988): 881-910.
4- Andersen, F. Alan. “Final Report on the Safety Assessment of Ceteareth-2,-3,-4,-5,-6,-7,-8,-9,-10,-11,-12,-13,-14,-15,-16,-17,-18,-20,-22,-23,-24,-25,-27,-28,-29,-30,-33,-34,-40,-50,-55,-60,-80, and-100.” International Journal of Toxicology 18.3_suppl (1999): 41-49.
5- See https://www.biopreferred.gov/BioPreferred/ for more information on the calculation of Bio-Based content.