Retroreflection in binary bio-based PLA/PBF blends

Abstract Corn starch based polylactide acid (PLA) and 2,5-furandicarboxylic acid (FDCA) based poly(butylene 2,5-furan dicarboxylate) (PBF) are melt blended together, and the binary bio-based blends show high reflectivity by several processing methods, including hot pressing, injection molding and 3D printing. We use optical microscopy to study the underlying structures and find that the phase separated and semi-crystallization morphology in the blends is the key structure. The large surface area of PBF droplets and smooth surface of PLA lamellar compose a retro-reflection geometry, which is similar to the tapetum lucidum in a cat's eyes. The conclusion in this study is applicable to other polymer pairs, and is adaptable in many processing technologies.