Bio-based poly(butylene 2,5-furandicarboxylate)-b-poly(ethylene glycol) copolymers with adjustable degradation rate and mechanical properties: Synthesis and echaracterization

Bio-based poly(butylene furandicarboxylate)-b-poly(ethylene glycol) copolymers are successfully synthesized through transesterification and melt polycondensation. The resulted polymers are characterized in terms of structural, thermal and mechanical properties. In addition, for the first time relevant hydrolytic degradation studies for the copolymers applications are systematically conducted in neutral and alkaline conditions. The PEG weight fraction ranges from 10% to 60%, as determined by 1 H NMR. Isothermal crystallization tests show that the copolymers own faster crystallization rate than that of PBF, with melting temperature higher than 120 degrees C. Water contact angle and water uptake characterizations show that the introduction of increasing amounts of PEG improves the hydrophilic character of the copolymers. Tensile tests clearly indicate that elongation at break drastically increase with PEG content, up to 5 times compared to PBF. From the Notched Izod impact tests, most samples are unbroken in the impact testing, showing excellent impact toughness. It is surprising to find that after water uptake, the PBF-PEGS still have acceptable mechanical properties. The weight loss during hydrolytic degradation is significant after 5 weeks for most of copolymers. With fast hydrolytic degradation rate and good mechanical properties, these copolymers own potential applications in areas like biomedical industry.