Synergistic Effect and Structure–Property of Bio-based 1,6-Hexanediol on Thermal, Mechanical and Degradation Properties of Biopolymers

The rising cost of petrochemicals owing to the rapid depletion of fossil resources has gradually divert research interest to novel chemicals derived from biomass feedstock. In this study we explored the synthesis, properties and ecotoxicity of a series of sustainable poly(hexylene 2,5-thiophenedicarboxylate- co -bis(2-hydroxyethoxybenzene)s (PTBHs) copolyesters suitable as form-fil-seal packaging materials. From the results, simply varying the ratios of HDO/BHEB afford control over the copolymers crystallinity, thermal and mechanical properties including degradability. The thermal analysis revealed the copolyesters possess satisfactory glass transition temperature (T g ) ranging from 75 to 112 °C and melting point from 160 to 205 °C, which are comparable to poly(ethylene furanoate) PEF and superior to poly(ethylene terephthalate) PET. These novel biopolymers exhibit tensile strength between 53 and 72 MPa and elongation at break of over 780%, higher than their corresponding homopolyesters. These promising properties were optimized with the increase of TH content, ranging from TB-enriched to TH-enriched copolyesters, exhibiting satisfactory heat-seal strength in the range of 0.77–0.45 N/mm. The biopolymers exhibit the potential as mere replacements to PETs, but their cost-rentability still needs to be investigated. Graphical Abstract The authors synthesized a novel class of fully non-toxic thiophene biopolymers and showed the synergistic effect of HDO on the structure, thermal and mechanical properties.