Tensile Property Balanced and Gas Barrier Improved Poly(lactic acid) by Blending with Biobased Poly(butylene 2,5-furan dicarboxylate)

A biobased poly(butylene 2,5-furan dicarboxylate) (PBF) is synthesized and blended with poly(lactic acid) (PLA). With only 5 wt % addition of PBF, the elongation at break of PLA becomes 18.5 times more than before, while the tensile modulus and tensile strength at yield keep almost the same. Morphological analysis based on scanning electron microscope pictures shows drastic shape deformation of PBF dispersed phases from sphere to fibril. The elongation ratio of PBF phase is much larger than that of PLA matrix, which is caused by a possible “plastic-rubber” transition in PBF during stretch process. On the other hand, stretch induced crystallization in PBF happened and it may increase the modulus of PBF along the tensile direction. Probably with the above two phenomena, PLA is dynamically toughened and strengthened in the elongation procedure. Moreover, the impact strength of the blends is better than those of the two pure components, and rubber-plastic transition and crystallization of PBF could improve the impact toughness too. The gas barrier property of PLA/PBF blends is also significantly enhanced by the introduction of a furan ring. It can be concluded that PLA/PBF blends are a good base material with great potential for future development in different areas.