Why is nylon durable and how does it have such exceptional strength?

Question

I was wondering how the chemical composition of a synthetic polymer such as nylon results in strength and durability.

Answer 1

Polyamides (such as Nylon) are molecules containing a large number of amide functions:

In those functions, the $\ce{C=O}$ bond is polarized (due to the difference in electronegativity between C and O) : $\ce{^{\delta+}C=O^\delta-}$. The N-H bond is polarized, too: $\ce{^{\delta-}N-H^\delta+}$. This leads to H-bonds between the chains:

While H-bonds are weak interactions, their high number (as there are a lot of amides in polyamide chains) leads to strongly bonded chains, which results in increased strength and durability.