Monomer is a Greek term that means “one part” or “one unit.” (Mono means “one”; mer means “unit.”) But beyond “monomer,” what is the liquid that we use day in and day out? We’ve listed the ingredients necessary in every formula, regardless of manufacturer.
Acrylic liquid consists of these major types of ingredients:
1. Monomer: Many different chemicals are classified as “monomers.” Manufacturers need to choose one that “is in liquid form,” says industry chemist Doug Schoon. “This monomer is going to be the workhorse and do the bulk of the heavy lifting in the work of creating nails.” The most common choice for monomers for traditional acrylic nails is ethyl methacrylate (EMA). EMA has adhesion properties to hold everything together, it resists cracking, and it spreads smoothly. Manufacturers choose a different monomer for “low-odor” formulas.
2. Inhibitor: To the monomer (EMA), manufacturers need to add a product that prevents premature polymerization (that’s when molecules prematurely link together into chains of molecules). If the molecules link too early, the monomer will harden in the bottle. Typically, manufacturers choose hydroquinone (HQ), hydroquinone monomethyl ether (MEHQ), or butylated hydroxytoluene (BHT) as inhibitors.
3. Catalyst: The catalyst speeds up the chemical reaction and allows the product to set up within minutes instead of hours. The reaction happens when the liquid comes into contact with benzoyl peroxide, which is the “activator” or “initiator” in the powder. It’s the catalyst that determines the set up time of the acrylic. Manufacturers can speed up or reduce the setup time by the amount of catalyst they add to their formula. However, they need to be careful; too much catalyst can discolor the acrylic and make the end product weaker.
4. Crosslinkers: Crosslinkers are added to a formula to link the strands of molecules together in a 3-D type web. Think of crosslinkers as rungs on a ladder, says Schoon. They bridge, strengthen, and connect molecular chains.
5. UV Absorbers: Like the name suggests, UV absorbers interact with UV light. They are added to prevent the nails from yellowing. They absorb the UV light and convert it to harmless blue light. With excessive amounts of a UV absorber, the nails could appear as if they have a blue glow.
6. Optional Ingredients:
Along with the essential ingredients listed above, some manufacturers add these optional ingredients:
Flow modifiers: EMA already has natural properties that make it spread smoothly, but flow modifiers are added to customize a product’s workability. They help to create an easy, smooth spread.
Wetting agents: These are added to help the product spread smoothly over the surface and to improve adhesion to solid surfaces, such as the nail plate or the acrylic that remains on the nail between services. Think of how water forms into droplets on the hood of a car immediately following a car waxing, says Schoon. As time passes, the wax wears away and water runs smoothly over the hood without beading up. In the case of acrylic nails, wetting agents help the product flow smoothly over the surface of the nail plate and down into the nooks and crannies. This is also why it’s so important to prep the nail correctly and remove oils, says Schoon. Any oil on the nail will prevent the wetting agents from working correctly and can block proper adhesion.
Dyes: Some manufactures add dyes to the liquid to achieve a desired effect. For example, blue acts as an optical brightener, which makes colors appear more vibrant. Think of the little blue dots you can see in some laundry powders, says Schoon. Those brighten the colors in clothes. In a similar way, blue dyes make whites appear whiter and colors appear brighter.