Final answer:
Coarse or resistant hair requires a stronger strength of chemical waving product due to the robust disulfide bonds present, which are more difficult to break compared to hydrogen bonds. A chemical like ammonium thioglycolate is needed to permanently reshape these bonds for a lasting wave.
Step-by-step explanation:
Most manufacturers of chemical waving products market different strengths because different types of hair require specific formulations to achieve the desired effect. The type of hair that would require a stronger strength of a chemical waving product is coarse or resistant hair.
This is because the disulfide bonds in the hair are stronger and more numerous than hydrogen bonds, which makes them more difficult to break and reshape.
Permanent waving products often contain a reducing agent like ammonium thioglycolate to reduce and rupture some of these strong disulfide bonds, allowing the hair to take on a new shape.
Temporary waves, on the other hand, involve the disruption of hydrogen bonds in the hair which can be achieved with water molecules and do not require harsh chemicals.
However, for permanent or long-lasting waves, stronger chemical treatments are necessary to alter the covalent disulfide bonds that give hair its structure and strength. Therefore, in the context of permanent and temporary waving, coarser hair types would necessitate a stronger formula to achieve the desired permanent wave.