When hair is wet, it absorbs water and swells. As it dries it releases water and shrivels. The shrinking and swelling can lead to hair damage called hygral fatigue.
What is polarity?
Water atoms are polar. This means that the atoms on one end have a negative charge whilst the atoms on the other end have a positive charge. Polar and non-polar atoms do not mix.
Generally, oils are non-polar but some oils have polar regions on them. This polarity gives them benefits to natural hair that non-polar oils do not have.
Polarity is relative - some oils have more polarity than others.
Examples of Relatively More Polar Oils
Examples of Non-polar Oils
When a polar oil makes its way into the hair fibre it reinforces it from inside and strengthens the structure. The higher the concentration of saturated fatty acids and monounsaturated fatty acids the better the ability of the oil to penetrate hair.
According to the Science of Black Hair, researchers have discovered that using polar oils such as coconut oil as a pre-shampoo treatment can protect the fibre against hygral fatigue.
Coconut oil and other polar oils prevents hair damage from hygral fatigue by reducing the extent to which the hair swells.
However, if you choose to pre-poo, make sure to do so with a polar oil. Using a non-polar oil will make it very tough to moisturise your hair.