Synthesis of fully bio-based polyamides with tunable properties by employing itaconic acid

•We synthesized a class of fully bio-based BDIS polyamide from large-scale biomass feedstocks.•Some BDIS possess both excellent mechanical property and good processability.•The tensile strength of the BDIS (IA-50%) fiber is comparable with that of commercial PA6 fiber.•Some BDIS polyamide could become elastic after absorbing water.•The BDIS (IA-50%, 80%) are transparent amorphous and tough polyamides.

A class of bio-based aliphatic polyamides (BDIS) was synthesized by melting copolycondensation from four biomass monomers: originated (SA), itaconic acid (IA), 1, 10-decanediamine (DD), and 1, 4-butanediamine (BD). IA was introduced into the system in order to adjust the chemical structure and the aggregation structures of the BDIS polyamide. Thus, some new polyamides with tunable properties were obtained, such as semi-crystalline polyamide with relatively low melting point, glassy polyamide with excellent toughness, and even rubbery polyamide after hydration. Some of the BDIS can be well melting spinned into fibers with comparable strength as polyamide-6. The BDIS with 100% itaconic acid can even be dissolved in ethanol, which makes it possibly be used by coating and dipping methods. In vitro cytotoxicity tests showed that these polyamides are nontoxic towards mouse fibroblasts and have great potential in biomedical applications.

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