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In this work, blends of monomer‐cast polyamide 6 (MCPA6) and polyurethane (TPU) were prepared by in situ anionic ring‐opening polymerization using caprolactam as the monomer and sodium hydroxide (NaOH) as the initiator. TPU degraded under weakly alkaline conditions to form an isocyanate group, which acted as a macromolecule activator to initiate the growth of the MCPA6 chain, and the formation of TPU‐co‐MCPA6 copolymer in this system, which improves the compatibility between MCPA6 and TPU. The MCPA6/TPU blends were tested for conversion, viscosity, and mechanical properties, and their structures and thermal properties were analyzed and evaluated by characterization techniques such as Fourier transform infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy. [ABSTRACT FROM AUTHOR]

Poly(lactic acid) (PLA) is known for its excellent overall properties and is widely used as a degradable material. However, PLA has poor toughness due to its inherent brittleness and low ductility. Poly(butylene adipate-co-butylene terephthalate) (PBAT) has good toughness and can be used to toughen PLA, while the poor compatibility between the two materials leads to ineffective toughening of PLA by PBAT, which needs to be modified by adding compatibilizers during processing. In this study, high-toughness PLA-based blends were prepared by in-situ polymerization using lactide as the reactive monomer and PBAT as the toughening agent, with the addition of industrial-grade epoxy oligomers ADR and PLA-PBAT-PLA triblock copolymers as solo or synergistic compatibilizers, to investigate the effects of ADR and PLA-PBAT-PLA on the compatibility and properties of PLA and PBAT. The inclusion of compatibilizers enhanced the interfacial bonding between PLA and PBAT and boosted the toughness of PLA/PBAT blends, and the addition of 0.15 wt% ADR or 0.15 wt% PLA-co-PBAT resulted in the impact strength of PLA/PBAT (75/25) blends reaching 150.09 kJ/m2 and 100.39 kJ/m2, respectively. The epoxy group of ADR reacted with the terminal hydroxyl or terminal carboxyl group of PLA and PBAT to form a chemical bond, which enhanced the melt strength and water absorption. PLA-PBAT-PLA forms a block structure between PLA and PBAT, which improves the fluidity and tensile strength of the blends. These findings provide fundamental data for PLA/PBAT compatibility studies and provide further development for PLA blend modification studies. [ABSTRACT FROM AUTHOR]