Excellent Gas Barrier Films: Interfacial Engineering and Compatibilization of Polyamide 6/Acrylonitrile‐Butadiene‐Styrene Copolymer ( <scp>PA6</scp> / <scp>ABS</scp> ) Blends via Janus Nanosheets

ABSTRACT In this study, the Janus nanosheets (JNSs) as compatibilizers have been applied in the immiscible polyamide 6/acrylonitrile‐butadiene‐styrene copolymer (PA6/ABS) blends. In the JNSs, polystyrene (PS) chains and epoxy groups were grafted on the opposite sides successfully where the epoxy functional groups can react with terminal carboxyl/amino groups of PA6 with ring‐opening condensation reactions during melt blending. The obtained JNSs with grafting PS and PA6 chains on each side of silica nanosheets can gradually migrate toward and be anchored at the phase interface with amphiphilicity and the pickering effect. The JNSs exhibited higher interfacial selectivity and compatibilization efficiency. At 2.0 wt% JNSs loading, the ABS dispersed phase transformed from spherical to irregular ellipsoidal shapes, likely due to the rigid characteristics of JNSs altering phase interface curvature and consequently modifying the blend's phase morphology. The gas barrier properties of the blending films can be significantly enhanced from 3.10 × 10 −15 cm 3 cm·cm −2 s −1 Pa −1 to 1.70 × 10 −15 cm 3 cm·cm −2 s −1 Pa −1 with 2.0 wt% JNSs due to the irregular dispersed phase structure and the presence of silica nanosheets at the interface. This study investigates interfacial structure and mechanical properties with JNSs compatibilizers, providing new insights for interface compatibilization strategies and construction of functional composites.