What Is Dilinoleic Acid/Butanediol Copolymer?
Dilinoleic Acid/Butanediol Copolymer is a man-made molecule created by linking together dilinoleic acid, a fatty acid most often derived from plant oils like soybean or safflower, with 1,4-butanediol, a small glycol commonly used in plastics. The result is a flexible, film-forming material that behaves much like a lightweight resin.
The idea of turning naturally sourced fatty acids into performance polymers started gaining traction in the 1990s when formulators were hunting for alternatives to heavier petrolatum-based ingredients. By combining bio-based dilinoleic acid with the well-studied butanediol the industry produced a polymer that could form smooth, breathable films yet still deliver a pleasant skin feel.
Manufacturing involves a condensation reaction: the fatty acid and the diol are heated under controlled conditions so their reactive ends join, releasing water and building long chains. Adjusting temperature, catalysts and reaction time lets chemists fine-tune the finished polymer’s viscosity and flexibility.
Because it forms an invisible shield that resists water and rub-off the polymer shows up in many leave-on products. You’ll see it in facial masks, long-wear foundations, primers, lipsticks, waterproof mascaras, sunscreens, hair styling creams, nail treatments and even some lightweight moisturizers that need a soft touch without a greasy after-feel.
Dilinoleic Acid/Butanediol Copolymer’s Cosmetic Benefits/Uses
This ingredient earns its place in formulas thanks to two main abilities:
- Film forming: Creates a thin flexible layer over skin or hair that locks in moisture, boosts product longevity and offers a smoother finish. In makeup it helps color stay put through sweat or humidity. In skincare it reduces transepidermal water loss for a softer complexion.
- Plasticiser: Makes otherwise brittle films feel supple and comfortable. This keeps mascaras from flaking, lipsticks from cracking and peel-off masks from pulling too hard when removed.
Who Can Use Dilinoleic Acid/Butanediol Copolymer
Dilinoleic Acid/Butanediol Copolymer is lightweight and non greasy so it generally suits all skin types from dry to oily and even sensitive. Its breathable film helps hold in moisture without the heavy feel that can bother breakout-prone complexions, and it is considered low on the clogging scale so acne sufferers usually tolerate it well. Those with very reactive or compromised skin should still keep an eye on how their skin feels since any film former can occasionally trap heat or sweat in hot weather.
The dilinoleic acid used to make this polymer is most often sourced from plant oils such as soybean or safflower and the 1,4-butanediol portion is synthetic. Because no animal-derived feedstocks are typically involved the ingredient is suitable for vegetarians and vegans, provided the finished product is not tested on animals and the brand confirms its supply chain.
Current data shows no specific risks for pregnant or breastfeeding women since the polymer stays on the surface of skin and is not known to penetrate or interfere with hormones. This is not medical advice and anyone who is expecting or nursing should still ask a doctor before adding a new cosmetic product to their routine, just to be safe.
The ingredient does not cause photosensitivity and you do not need to adjust your sun protection when using products that contain it. It is also fragrance free and free of common allergens like gluten or nuts, which makes it a straightforward option for people avoiding those triggers.
Potential Side Effects/Adverse Reactions
Responses to any cosmetic ingredient can differ from one person to the next. The effects listed below are possible yet uncommon when Dilinoleic Acid/Butanediol Copolymer is used correctly in a well-formulated product.
- Mild skin irritation such as temporary redness or itching
- Contact dermatitis in individuals allergic to one of the component raw materials
- Blocked pores or small breakouts in extremely congestion-prone skin, especially if combined with other heavy ingredients
- Stinging around the eyes if the product migrates into the ocular area
If you notice any of the reactions above stop using the product and seek advice from a qualified healthcare professional.
Comedogenic Rating
Rating: 1 / 5
Dilinoleic Acid/Butanediol Copolymer is a high-molecular-weight polymer that stays mainly on the surface of skin and does not behave like a traditional oil. Its flexible film is breathable and non-greasy so it rarely blocks pores on its own, earning it a low score of 1. People who are prone to acne or breakouts can usually use products containing this ingredient without added risk, provided the rest of the formula is also light and non-comedogenic. Keep in mind that pairing the polymer with heavier waxes or butters may raise the overall clogging potential of the finished product.
Summary
Dilinoleic Acid/Butanediol Copolymer works as a film former and plasticiser. It creates a soft, invisible layer that locks in moisture and helps makeup, sunscreen or hair products stay put while keeping the film flexible so it does not crack or flake. Although not as famous as silicones or traditional resins, it has carved out a steady niche in long-wear cosmetics, peel-off masks, waterproof mascaras and lightweight moisturizers where formulators want performance without a heavy feel.
Current safety data shows it is well tolerated by most skin types with low irritation and comedogenic risk. As with any new ingredient it is wise to patch test a product that contains it to make sure your individual skin agrees.