Biobased composites of poly(butylene furanoate) copolymers and hemp

Abstract

There is growing interest in biodegradable and bio-based materials that can replace conventional plastics in applications such as packaging. Polymers based on 2,5-furandicarboxylic acid (FDCA) have been proposed as bio-based analogues for polymers based on terephthalic acid. However, they tend to be brittle, exhibit limited biodegradability, and there are few examples of biocomposites from these polymers. Described here is the preparation of a small library of copolyesters based on FDCA, 1,4-butanediol, and either succinic, adipic or sebacic acid. By incorporating different dicarboxylic acids in varying ratios, the glass transition temperature was tuned from −30 to 41°C and the melting temperature from 104–171°C while maintaining high stability up to ~300°C. Incorporation of aliphatic dicarboxylic acids facilitated blending of the copolymers with hemp powder, with up to 30 wt% hemp incorporated into the polymer containing 60:40 FDCA:sebacic acid. Incorporation of hemp did not substantially alter the thermal properties but increased the moduli of the composites. The copolyesters were susceptible to degradation by Rhizopus oryzae lipase, with the sebacic acid-containing polyester having higher degradability than the succinic acid-containing polyester. Overall, the results demonstrate the promise of the copolyester-hemp blends for applications where they can replace conventional non-degradable plastics.