Unsaturated polyamides from bio-based Z-octadec-9-enedioic acid

A series of polyamides based on Z-octadec-9-enedioic acid, a bio-based unsaturated monomer, and aliphatic-, cycloaliphatic-, or benzylic diamines were synthesized and characterized by H-1 and C-13 NMR analysis, size exclusion chromatography (SEC), DSC, and dynamic-mechanical analysis (DMA). The high reaction temperature (250 degrees C) did not lead to the degradation of diacid unit double bonds and unsaturated polyamides were obtained. The aliphatic unsaturated polyamides are semi-crystalline polymers of high molar mass, relatively flexible at room temperature. The cycloaliphatic unsaturated polyamides are semi-crystalline or amorphous, present higher melting and glass transition temperatures and are much more rigid. The aliphatic and aliphatic-aromatic unsaturated polyamides present lower T-g and T-m as compared to their parent saturated polymers.