Published September 1977
Lactams are cyclic amides. They undergo ring-opening polymerization to form polyamides. The most common example is caprolactam, the monomer for nylon 6. Caprolactam has been treated extensively in earlier reports of the Process Economics Program (Reports 7, 7A, and 7B).
Lactams containing from 4 to 12 carbon atoms have become of increasing interest in recent years, especially for making new polyamides. Some of these new polyamides have been discussed in Report No. 94 of the Process Economics Program. The two other lactams of the greatest inte est at present are laurolactam and Y-butyrolactam, with 12 and 4 carbon atoms, respectively. Laurolactam and Y-butyrolactam have quite different physical properties and are produced by entirely different processes.
Laurolactam, the monomer for nylon 12, is generally made from cyclododecatriene produced by butadiene trimerization. Two different routes in commercial use are evaluated in this report. Each route has several steps.
Y-Butyrolactam, also known as 2-pyrrolidone, has been made on a small scale for many years. It is used as a solvent and specialty chemical and is the monomer for nylon 4. If nylon 4 becomes commerical, butyro lactam demand can be expected to increase markedly.
Butyrolactam is made from butyrolactone and ammonia. The two commercial routes to butyrolactone, starting from 1,4-butanediol or from maleic anhydride, are evaluated in this report. Also evaluated is a proposed route from maleic anhydride directly to butyrolactam. This report was prepared with the assistance of reference books, brochures, published articles, discussions with manufacturers, and the patent literature through March 1977.