Nylon‐9 from unsaturated fatty derivatives: Preparation and characterization

Abstract Methyl azelaaldehydate, soy nitriles, and oleonitrile were compared as starting materials for making nylon‐9. Less difficulty was encountered in purifying intermediates from oleonitrile than from the other two. All 3 routes involved hydrolysis of methyl 9‐aminononanoate to 9‐aminononanoic acid. Self catalyzed hydrolysis of the amino ester in water produced low yields of monomer owing to oligomer formation, but hydrolysis in the presence of barium hydroxide was more successful. Polymerization of the amino acid proceeded smoothly with 9‐acetamidononanoic acid used to control mol wt. Strength and moisture absorbing properties were determined for nylon‐9, as well as for nylon‐6/9, ‐9/11, and ‐9/12 copolymers. Nylon‐9 has attractive properties, offering tensile yield and flexural strengths approaching those of nylon‐6, while having low water absorption closely approaching that of nylon‐11 and ‐12. The cost of producing 10,000,000 lb/year of nylon‐9 from purchased oleonitrile was estimated to be .99/Ib at 100% yield and $2.18/Ib at 35.5% yield. Further process development is needed before yields in a commercial plant can be forecast.