Nylon 12 (PA12): Properties, Production, and Ring-Opening Challenges

Nylon 12 (PA12) is a widely produced material with an annual world production of 70,000 tons. It exhibits excellent electrical insulation, dimensional stability (although weaker than PA11), and maintains robust strength under high relative humidity or sub-zero ambient temperatures. Furthermore, it is one of the least dense types of nylon, making it an ideal material for various industrial applications.

The industrial raw material for PA12 is dodecalactam, which is synthesized through a process involving dehydrogenation of cyclododecanol and cyclododecanone under the action of a catalyst at 230-245ﾰC and atmospheric pressure. The resulting pure cyclododecanone is then subjected to an oxime reaction and oxime rearrangement to produce laurolactam.

However, the ring-opening reaction of dodecalactam is more challenging and often requires the addition of acids, amino acids, or nylon salts as ring-opening aids. This step is crucial for the polymerization process that ultimately leads to the production of PA12.