Why does cotton burn so easily?

Question

I am doing a science experiment and NEED to know why cotton, rayon, silk, polyester and nylon burn so easily. On the opposite - do you know why wool doesn't burn at all?? PLEASE HELP!!!

Answer 1

Because wool is essentially sheep hair, made out of protein (keratin?) and materials like polyester, nylon, etc are composed of only carbon, hydrogen and a bit of oxygen (which burn easier - like hydrocarbons).

Answer 2

because it traps air