Novel Biobased Polyamide Thermoplastic Elastomer with Medium Hardness

Thermoplastic elastomers (TPEs) are useful in various engineering and healthcare applications. A new fully biobased polyamide TPE (PA36,9) with medium hardness is reported. The elastomer is synthesized using a fatty dimer amine and azelaic acid, via one-pot melt condensation polymerization. The resulting elastomer shows a melting temperature of 83.6 °C, a medium hardness (Shore A/Shore D = 90/35), a large elongation at break (1220%), good resilience, and impact resistance, while maintaining high tensile strength (31.8 MPa), low density (0.93 g cm−3), and hydrophobicity. The chemical structure of the repeating unit, together with the molecular weight and molecular weight distribution, of the polymer governs the properties of the resulting polyamide, which differ from those of conventional aliphatic polyamides. This biobased polyamide elastomer is a promising candidate to substitute some fossil fuel-based medium-hardness TPEs for applications, such as insulation, sealing, automotives, and construction.