Copolyamides derived from brassylic acid



Polyamides were prepared from C6 to C12 diamines with brassylic acid, a linear C13 dicarboxylic acid, derived from Crambe seed oil. One distinct characteristic of these polymers is their low moisture adsorption as compared to nylon 66 and nylon 6. To modify the properties of these nylons, multi-component copolyamides were prepared from hexamethylene diamine and mixtures of brassylic acid with adipic, terephthalic, or isophthalic acids. It was found that the melting points of the co-polyamides were changed by the choice and the levels of the diacids used. The melting point-composition curves all show a eutectic minimum. The glass transition temperature of nylon 6,13 is also changed by the incorporation of other diacids. Water adsorption of nylon 6,13 increases with increased substitution of brassylic acid by other diacids in the order of adipic > isophthalic ≥ terephthalic. Mechanical properties of some copolyamides are in the same range as the commercial nylon 11 and nylon 12. The low moisture absorption, reduced fabrication temperature, and the wide range of properties obtainable through copolymerization make copolyamides derived from brassylic acid potentially suitable as specialty tubing, powder coatings, and molded machine parts. They will be commercially viable when brassylic acid becomes available on a large scale and is competitively priced.