Skim through
What it does: emollient, conditioning
The science
Cetyl ester is primarily used to thicken emulsions while acting as an emollient for improved feel. It also prevents formulas from separating.
Benefits for your hair
Conditions hair
As it is water repellant, moisture loss is prevented and thus, it is a great conditioning agent.
TLDR
Cetyl ester is a great ingredient for conditioning and improves the application process.