Biobased Poly(Butylene Furanoate) Modified by Some\nAliphatic Diacids toward Poly(Butylene Alkylene-<i>co</i>-furanoate) (PBXF) Series with Tunable Physical Properties and Biodegradability

A series\nof biodegradable poly(butylene alkylene-<i>co</i>-furanoate)\n(PBXF) copolymers were synthesized by incorporating the\nthird monomer with varying numbers of methylene (0, 2, 4, 8, 12, 16)\ninto the poly(butylene 2,5-furandicarboxylate) (PBF) backbone. Systematically,\nthe effect of varying the alkylene length in butylene alkylene (BX)\nunits on the properties of PBXFs was investigated. Results reveal\nthat slight variations in the alkylene length will result in dramatic\ndifferences in material properties. The crystallizability of PBXFs\nsignificantly improved when the number of methylenes exceeded 8. The\nmechanical properties illustrated that PBXFs exhibited outstanding\nductility, with elongation at a break exceeding 880%. Additionally,\nPBXFs retained excellent barrier properties compared to most commercial\nmaterials, and the underlying barrier mechanisms were further explored\nthrough simulations. More importantly, the degradation properties\nof PBXFs indicated that the optimum degradation properties occurred\nin the lipase solution medium, and remarkable biodegradation was observed\nwith sufficiently elongated alkylene length. These observations profoundly\nexplain the effect of varying alkylene length of BX units in PBXF\nmacromolecules concerning structural properties, guiding the development\nof high-performance biobased degradable polyester materials.