What Is Polyacrylate Crosspolymer-9?
Polyacrylate Crosspolymer-9 is a lab made polymer created by linking together tiny building blocks called t-butylaminoethyl methacrylate and carboxyethyl acrylate. These chains are then “cross-stitched” with special connectors derived from pentaerythritol and toluene diisocyanate, which lock everything into a three-dimensional net. Because it is entirely synthetic, it does not come from plants or animals and its quality and purity can be controlled from batch to batch.
The technology behind this ingredient grew out of the search for lightweight film formers that could stay flexible on the skin. Chemists found that adding multiple functional groups to an acrylic backbone gave the finished polymer the right mix of clarity, strength and comfort, making it a hit in modern cosmetic labs during the early 2000s.
Manufacturing starts with liquid monomers that are mixed in a reactor. Heat or UV light triggers them to join into long chains. Crosslinkers are added at precise moments so the chains bond together instead of sliding apart, creating tiny microgels that swell in water yet stay clear. After filtering and drying, the powder or pre-swollen gel is ready to be added to skincare blends.
Thanks to its film forming talent, Polyacrylate Crosspolymer-9 pops up in many product types: lightweight moisturizers, makeup primers, peel-off masks, long wear foundations, anti-aging serums and hair styling creams. It helps these formulas glide on smoothly and hold their shape once they set.
Polyacrylate Crosspolymer-9’s Cosmetic Benefits/Uses
In beauty formulas Polyacrylate Crosspolymer-9 is valued for one main job.
As a film former it creates an invisible, flexible layer on skin or hair. This thin coating locks in moisture, smooths texture, improves spreadability and boosts the staying power of pigments or actives. The result is softer skin, longer lasting makeup and hairstyles that resist humidity without feeling stiff.
Who Can Use Polyacrylate Crosspolymer-9
Thanks to its light, breathable film Polyacrylate Crosspolymer-9 is generally suitable for all skin types, including oily, combination, normal and dry. Its non‐occlusive feel means it will not trap excess oil, so acne-prone users usually tolerate it well. Sensitive skin can also benefit because the polymer itself is inert and fragrance free, though any formula add-ons should be taken into account.
The ingredient is entirely synthetic with no animal-derived raw materials, making it appropriate for vegans and vegetarians. It is also kosher and halal compliant when sourced from reputable suppliers.
Current safety data show no specific concerns for pregnant or breastfeeding women when the polymer is applied topically in cosmetic amounts. This is not medical advice, and anyone expecting or nursing should still clear all skincare products with a qualified doctor just to be safe.
Polyacrylate Crosspolymer-9 is non-photosensitising, so it does not raise the skin’s sensitivity to sunlight. It has no known interactions with common actives like retinol, vitamin C or acids, and it plays well in both leave-on and rinse-off products.
Potential Side Effects/Adverse Reactions
Reactions to topical Polyacrylate Crosspolymer-9 differ from person to person. The issues listed below are only potential effects and are unlikely to occur for the average user when the ingredient is properly formulated.
- Mild redness or irritation
- Itchy sensation in very sensitive skin
- Contact dermatitis if combined with other irritants
- Eye stinging if the product accidentally migrates into the eyes
If you experience any of these reactions stop use and consult a healthcare professional.
Comedogenic Rating
Rating: 0 / 5
Polyacrylate Crosspolymer-9 is a large, water-affinity polymer that does not melt into pores or leave an oily residue. Because it sits on the skin surface as a breathable film and is removed easily with normal cleansing, it has virtually no tendency to clog follicles. For those prone to acne or breakouts the ingredient is considered safe and unlikely to trigger comedones.
Additional note: its low usage levels in formulas (often under 2 %) further reduce any pore-blocking risk, even when paired with richer emollients.
Summary
Polyacrylate Crosspolymer-9 is mainly a film former that lays down an invisible flexible layer, locking in light moisture, improving slip and extending the wear of pigments or actives. It achieves this through its crosslinked acrylic network that swells slightly in water yet remains clear and smooth on the skin.
The polymer enjoys steady popularity in primers, long wear makeup and lightweight skincare, although it is not as ubiquitous as classics like carbomer. Formulators reach for it when they need a modern, comfortable film without tackiness.
Current data show it is low risk, non-sensitising and free from major health concerns. Still, every skin is unique so it is wise to patch test any new product containing Polyacrylate Crosspolymer-9 before full use.