Naked Science Forum

Life Sciences => Physiology & Medicine => Topic started by: george on 13/10/2006 22:59:03

Title: How does a Hair Perm Work?
Post by: george on 13/10/2006 22:59:03

How does a perm work? What does it do to the hair to make it curly, and why do some people have an "auto-perm" i.e. naturally curly hair?

George

Title: Re: How does a Hair Perm Work?
Post by: rosy on 14/10/2006 10:31:17

I'm not sure why some people's hair is curly, but I believe a perm is created by exploiting the chemistry of the hair itself:
Hair is made of a type of protein which is held together partly by disulphide bonds- bonds between two atoms of sulphur either within the protein or between neigbouring protein molecules. Applying a reducing agent to the hair breaks these bonds (takes disulphide -S-S- to two seperate thiols -SH HS- ) making the hair much less stiff. The hair is then formed into the desired styl and reoxidised so that new disulphide bonds form in the new position.

Does that help?

Title: Re: How does a Hair Perm Work?
Post by: gecko on 27/10/2006 06:30:34

the elementary answer as to why hair is curly or straight: straight hairs are round, and therfore stay straight, like a cylinder, while curly hairs are flat, and curl like a ribbon.

but i dont know how a perm works.