8. Conclusion

Since the 1920s, nitrocellulose nail varnishes have dominated the market. Their composition has changed little since then, and mainly contains five essential components: a film-forming agent, one or more resins, a plasticizer, one or more solvents and a thixotropic agent. The addition of organic or mineral pigments and mother-of-pearl enhances nail polish ranges and visual effects, while various additives are incorporated to make "care" claims, for example. Nail polishes are therefore complex formulations that have to meet stringent specifications. On a technical level, improvements in performance are still awaited, particularly in terms of gloss and hold, while on a physicochemical level, the adhesion of the varnish film to the nail and the mechanisms involved need to be better understood.

The main challenge today is to obtain 100% biobased varnishes, when current...