What are the monomeric repeating units of
Question:

What are the monomeric repeating units of Nylon-6 and Nylon-6, 6?

Solution:

The monomeric repeating unit of nylon 6 is $\left[\mathrm{NH}-\left(\mathrm{CH}_{2}\right)_{5}-\mathrm{CO}\right]$, which is derived from Caprolactam.

The monomeric repeating unit of nylon 6,6 is $\left[\mathrm{NH}-\left(\mathrm{CH}_{2}\right)_{6}-\mathrm{NH}-\mathrm{CO}-\left(\mathrm{CH}_{2}\right)_{4}-\mathrm{CO}\right]$, which is derived from hexamethylene diamine and adipic acid.