Friends who often perm their hair know that they have been permedhairMonths or even a year are still rolled, even if they are usedwaterIt does not straighten when wet and is long-lasting. It’s different from this, becauseGo to bedCurly hair, as well as hair bent with hairpins, are called “temporary curls” and can be restored to their original shape after being dipped in water. Why is this?
The reason why these curly hairs are different is related to the way the four main molecules bind between the keratin proteins in the hair. In order from weak to strong, these binding methods are hydrogen bonds, ionic bonds, disulfide bonds (-S-S-, S refers to sulfur), peptide bonds, and the largest number of hydrogen bonds.
When we curl our hair with a perm curl, in addition to the peptide bonds, the other 3 bonds in the hair will be cut off by the high temperature. At this time, the attached object changes, causing the hair to curl.
And because the hair is bent while sleeping, only hydrogen bonds are working. Since the disulfide bond that can restore the hair to its original state is not broken, the hair can return to its original state as soon as the hydrogen bond is broken after immersion in water.
In addition to hydrogen bonds, the composition of perms also has chemical agents. The hair is fixed by the agent in a bent state, so the ionic bonds and disulfide bonds will not be broken even if they are soaked in water, and the hair will not easily return to its original shape.
