β‐Lactams, Their Polymerization and Use as Raw Materials for Fibers

Abstract β‐Lactams can be prepared by cyclization of β‐aimno acid esters. Recently they have become available also from olefins by addition of N‐carbonysulfamyl chloride (isocyanatosulfonyl chloride) and from aldehydes by reaction with N‐carbonylsulfamyl chloride and ketene. Condensative or anionic polymerization results in polyamides the chains of which contain many more amide groups than the chains of polyamides of the nylon‐6 type. Hence the new polymers resemble silk moreclosely. Fibers and films can be prepared from solution.