Green chemistry for high impact colour cosmetics

According to Mintel Group, ingredients are a top concern for consumers and the demand for clean formulations with proof of results will become the expectation of consumers in the near future.1 Clean ingredients will help brands gain consumer trust and transparency will be a critical element of that success. In the colour cosmetics market, performance cannot be a trade-off for clean formulations and brands will be required to demonstrate strong proof of results. Following the mega-trend of social media influencers, bold colours and exciting textures will be drivers for new product success. 

Polyester ingredients deliver impactful performance

Polyesters are an important class of cosmetic ingredients. There are over 200 different types of polyesters listed in the International Cosmetic Ingredient Dictionary and Handbook with a variety of functions, including film-forming and conditioning agents for skin and hair.2 Polyesters are polymer chains comprised of repeat units linked by ester bonds as shown in Figure 1. Polyester backbones are polar due to the ester bonds and the degree of polarity is controlled by increasing/decreasing aliphatic content in the backbone and the polymer chain end groups. Generally polyesters are hydrophobic and insoluble in water but can be rendered water-dispersible or watersoluble by incorporating hydrophophilic ionizable groups into the backbone. Polyesters can be linear, branched, and/or crosslinked and the difference in the structure modulates critical physical properties such as viscosity and film formation. The polyester chemical structure can also be varied to modulate compatibility in solution and on surfaces, solubility properties, and dispersion properties. Two polyester molecules will be discussed in this paper. The primary structure of both molecules is shown in Figure 2 and the structure variations are referenced in the respective sections about this polymer.