Wow, this thread is so timely for me cuz I have just been trying to google “hair oils” and such to try and figure out, ummm, hair oils. So far, found this abstract of an article (I can’t find the whole thing, but I’ll keep looking):
http://www.blackwell-synergy.com/doi/abs/10.1111/j.0142-5463.2005.00278_3.x that suggests polyunsaturated oils do not penetrate or do so sparingly because of their large molecules, but monounsaturated oils do readily penetrate hair because they have more compact (smaller) molecular structure. Soooooooo, I’ve come to the following tentative conclusions:
1. all oils “lubricate” – that is they reduce friction by providing a smooth film as a covering over parts that move against each other. However, hair oils can be categorized two ways:
2. penetrating oils: the kind that actually “absorbs” into the hair or skin and I believe these are the more “moisturizing” oils, especially when used on WET hair because they emulsify with the water and then penetrate. Some mono/penetrating oils are: castor, jojoba, emu, olive, rapeseed, hazelnut, almond, avocado, sesame, etc. (please correct and/or add to this list)
3. sealing oils: the kind that create “barrier” on top of the hair or skin, sealing things in or out. So, maybe these oils will weigh wet hair down more because doesn’t penetrate inside with the water, but rather sits on top going nowhere. I think they may work well when used very sparingly on DRY hair. Some poly/sealing oils are: sunflower, safflower, corn (please correct and/or add to this list)
4. Popular hair oils I did not find a definitive answer: coconut, palm oil, palm kernel nut oil = these are “saturated” fatty oils so can’t figure out where they fit in the penetrating vs. sealing categories
Hmmmm, in light of Sisterslick’s explanation, perhaps should be looking at the SIZE of the oil molecules and not whether it is mono or poly? IDK . . . .