High-entropy polymer blends utilizing in situ exchange reaction

High-entropy metal alloys comprising near-equimolar multiple elements have attracted considerable attention, and high configurational entropy is the main reason behind their outstanding performance. Analogical material design is expected to be applied for polymer blending; however, high-entropy polymer blends are still an undeveloped field owing to their long-chain structure. Increasing configurational entropy is essential for preparing high-entropy polymer blends, and to realize monomer unit dispersion beyond molecular chains, multi-component blending, utilizing an in situ exchange reaction, was investigated. Four types of aliphatic polyamides were employed as component polymers, and binary-to-quaternary blends were fabricated. Ternary and quaternary blends exhibited restricted crystallization behavior and high elongation at break. These characteristic behaviors were not observed in the reacted binary blends or unreacted quaternary blends. Numerical assessment revealed that the randomness of the molecular sequence in the reactive quaternary blend rapidly increased during melt mixing. • Reacted ternary and quaternary blends were proposed as high entropy polymer blends. • Randomness of molecular sequence in blends was enhanced by reactive extrusion. • Exchange reaction ratio affects crystallization and transparency of multiple blends. • Novel high-entropy polymer blends show good toughness and transparency.