Compatibilization and Property Enhancement of Polyamide 11/Poly(Phenylene Oxide) Blends via Maleic Anhydride–Grafted Poly(Phenylene Ether)

ABSTRACT Polyamide 11 (PA11) is a bio‐based polymer with high mechanical strength and chemical stability, but its applications are limited by poor flame resistance and thermal stability. In this work, PA11 was blended with poly(phenylene oxide) (PPO), an engineering polymer with intrinsic flame retardancy, using poly(phenylene ether)‐grafted‐maleic anhydride (FB) as a compatibilizer. Blends containing 80 wt.% PA11 and 20 wt.% PPO with varying FB loadings (1 wt.%–7 wt.%) were prepared by melt blending and hot pressing. Morphological analyses by SEM revealed that FB significantly reduced PPO droplet size and improved phase dispersion, while FTIR confirmed interfacial chemical interactions. DSC results demonstrated increased PA11 crystallinity and disappearance of PPO transition peaks, indicating enhanced compatibility. Mechanical testing showed that the blend with 5 wt.% FB achieved optimal performance, with tensile strength of 45.6 MPa, tensile modulus of ~558.5 MPa, and elongation at break of 38.0%. Flame‐retardancy tests further revealed improved performance, with a UL‐94 V‐2 classification and a limiting oxygen index (LOI) of 24.5%. These findings demonstrate that FB compatibilizer effectively enhances the compatibility, mechanical strength, and flame resistance of PA11/PPO blends, highlighting their potential as sustainable engineering materials.