Often the term “bonder” is applied to gel systems, and “primer” is for acrylic, but they both have a similar function in that they bind to the keratin in the nail bed to create a stronger bond for the enhancement product. So what are they made of? And what is the difference between the two?
What Are They Made Of? The majority of primers and bonders on the market consist of about 10 different resins, which are used in different combinations to meet the manufacturers’ desired function. So the ingredients in a primer can be similar to a bonder, but a gel bonder will have an increase in the amount of resins that react to UV light, and the primers will focus on air-drying resins.
A popular resin currently being used in gel bonders is called a BISGMA, which is UV light-activated and also popular in the dental industry for fillings and fastening crowns on teeth.
Older primers for acrylic systems used acid-based primers, mostly methacrylic acid, which is not to be confused with methyl methacrylate (MMA). Methacrylic acid has a chemical structure that bonds better with the keratin in the nail and makes it more receptive to bonding with the acrylic enhancement product. And methacrylic acid does not cause the allergies that MMA does.
Most often, a primer will consist of a blend of chemicals to reduce the acidity on the nail bed.
How Are They Different? Both primers and bonders chemically prepare the surface of the nail for better adhesion for the enhancement product. Primers will work to modify the pH of the nail bed, bonding with the keratin in the nail bed, while also leaving part of itself exposed above the nail bed to bond with the acrylic.
Bonders will use UV light-activated ingredients to achieve a similar effect, where part of the product is embedded with the natural keratin in the nail, while also remaining partially exposed to bond with the gel product.
Structure Is Function
An interesting thing to note is that the resins and chemicals that make up primers and bonders are not drastically different than the ingredients in the actual acrylic and gel enhancement products. It’s just that the final molecule shape has a different structure that enables it to work better as an adhesive product.
In chemistry, the actual shape of the molecule has a strong impact on how that molecule will function or perform. Sometimes molecules are made of similar components but have significantly different functions and effects.