What is the synthetic precursor of pa?

Polyamide (PA), commonly known as nylon or nylon, is the general name of thermoplastic resin with repeated amide groups (-NH-CO-) in its molecular chain. Include aliphatic PA, aliphatic-aromatic PA and aromatic PA. PA can be divided into two types according to the structure of synthetic precursors, one is formed by amino acid polycondensation (including lactam ring-opening polymerization), and the other is formed by diamine and diacid polycondensation.

Bio-based nylon is a polymer material synthesized by biological, chemical and physical means with biomass renewable resources as raw materials, including bio-based lactam, bio-based diacid, bio-based diamine and so on. And then polymerized and synthesized. Has the characteristics of environmental protection and renewable raw materials.