Abstract:  The utilization of natural renewable resources has attracted more consideration due to environmental concerns. Therefore, plastic materials derived from renewable resources are gaining growing interest both in scientific research and industry for the replacement of petroleum-based ones. Polyamides (PAs) are one of the most frequent engineering polymers with very good thermal and mechanical properties which have various applications in the industries such as automobile parts, packaging, and electrical and electronic devices. In the current study, Bio-based fats and oils were used as monomers for the synthesis of long-chain aliphatic PAs via melt polycondensation. In addition, thiol-ene-based click chemistry was applied in chain extension to prepare difunctional monomers with up to 32 carbons. The synthesized bio-based PAs displayed number average molecular weights up to 55,000 g/mol. This class of polymers exhibited an impressive property profile, polyolefin-like impact strength, tear strength, high elasticity, very low water absorption, and yet high oxygen- and water vapor permeability. The technical advantages of these polymers encourage further development of composite materials with various reinforcing fillers such as fibers, graphene, clay, etc. The glass transition temperatures were above room temperature (45–55 °C), while melting temperatures ranged from 121 to 200 °C. Relatively low melting temperatures of these bio-polyamides enable favorable compounding with some sensitive bio-based fillers such as cellulose and lignin.

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