What are the monomers of nylon 6 and nylon 6, 6?

The name Nylon actually holds the secret to its raw materials. The so-called "monomers" are the basic building blocks used to create these long plastic chains.

● Building Blocks of Nylon 6: Caprolactam

Nylon 6 is special because it only needs one type of building block to construct itself.
Monomer name: Caprolactam.
Its appearance: You can imagine it as a tightly closed "ring." This ring contains exactly 6 carbon atoms.
Manufacturing process: In the factory, this ring is heated. When heated, the ring "breaks" in the middle, becoming a straight short chain. Because both ends of the short chain have strong attractive forces, they connect end-to-end, quickly forming a very long chain—this is Nylon 6.
Why is it called 6: Because its only raw material contains exactly 6 carbon atoms.

● Building Blocks of Nylon 66: A Double Act

Nylon 66 is like a duet; it requires two different building blocks to connect alternately.
First building block: Adipic acid. It provides 6 carbon atoms.
Second building block: Hexamethylenediamine. It also provides 6 carbon atoms.
Manufacturing process: When these two materials are mixed together, they attract each other like the positive and negative poles of a magnet. One adipic acid molecule joins with one hexamethylenediamine molecule, and they "squeeze out" a water molecule during the connection. They continue to connect alternately, forming a stronger long chain.
Why is it called 66: Because each of its two raw materials contributes 6 carbon atoms, so it's called 66.