 Ring opening can be carried out by cationic or anionic initiators, although cationic initiators have not been used commercially due to the product being less stable and oxidized relatively quickly in comparison to those produced by activated anionic polymerization (monomer casting).Ring-opening polymerization is the preferred route for commercial production.Nylon 12 exhibits properties between short chain aliphatic nylons (e.g., nylon 6 and nylon 66) and polyolefins.