Chapter 11, Problem 86P

Skin moisturizers come in two types, (a) One type of moisturizer is composed mainly of hydrocarbon material. Suggest a reason as to how a moisturizer of this sort helps to keep the skin from drying out. (b) A second type of moisturizer is composed mainly of propylene glycol $\left[{\text{CH}}_{\text{3}}\text{CH}\left(\text{OH}\right){\text{CH}}_{\text{2}}\text{OH}\right]$ . Suggest a reason as to how a moisturizer of this sort helps to keep the skin from drying out.