A 2009 study on oils (Brazilian nut, mineral oil, passion seed, palm olein, buriti, palm stearin) and butters (ucuúba, sapucainha, tucumã) demonstrated that the former may be the better option when it comes to combing ease, gloss, and reduction in split end formation. This conclusion is linked to the "molecular chain conformation" of triglycerides in oils versus in butters. The triglycerides in the butters studied have more branches and higher melting points, both of which may increase friction and thus decrease the ease of spreading. What does this mean in plain English? Well, think of it this way: Because butters are harder to spread on the hair, they may not be as effective as oils in terms of combing ease, luster, and minimizing split ends. (Some of you are probably saying "Duh!!" right now simply based on just experience. Lol.)
Another conclusion from the study is that ucuúba butter improves the tensile strength of hair -- which is something that all the other oils and butters studied did not do. The thought is that the low molar mass triglycerides of ucuúba butter are able to penetrate into the hair (you know, like coconut oil).
So, in short, choose the oil over the butter if you want more sheen + less breakage and splits.
ABSTRACT TO STUDY:
OILS AND BUTTERS: THE EFFECT OF DIFFERENT FATTY ACID CHAIN COMPOSITION ON HAIR (2009)
