Unexpected enhancements of biobased poly(butylene 2,5-furandicarboxylate) by blending with biodegradable poly(ε-caprolactone)

•Fully sustainable blends of biobased PBF and biodegradable PCL were prepared by melt-mixing.•Despite the absence of PBF crystals, PCL induces formation of oriented precursors upon injection.•Such PBF/PCL blends show unexpected enhancements of both thermal and mechanical properties. Herein, we prepared sustainable polymer blends of biobased poly(butylene 2,5-furandicarboxylate) (PBF) and biodegradable poly(ε-caprolactone) (PCL) by melt-compounding, and studied the structure, thermal and mechanical properties of PBF-rich mixtures. Despite the inability to induce generating PBF crystals upon injection molding, PCL makes PBF’s cold crystallization easier via formation of oriented precursors. Strikingly, such compounds show unexpected enhancements of both thermal and mechanical properties relative to PBF, and the compound containing 5 wt% PCL displays the best mechanical performance.