Effect of Glycidyl Methacrylate Grafting Onto Polyketone on the Mechanical Properties and Hygrothermal Resistance of Polyketone/Polyamide 6 Blends

ABSTRACT To balance the mechanical performance and hygrothermal resistance, polyketone (POK) was blended with polyamide 6 (PA6), and glycidyl methacrylate (GMA)‐grafted POK was further introduced to improve the compatibility with PA6. In the present study, GMA‐grafted POK was prepared via in situ reactive melt compounding. GMA grafting reduced the melting and crystallization temperatures of POK and also lowered its crystallinity. At the same time, the equilibrium water uptake decreased from 2.92% to 1.97% after GMA grafting, while the tensile modulus retention increased from 71.9% to 83.4%. A series of blends with graded PA6 contents were prepared by melt blending POK or GMA‐grafted POK with PA6. For the PA6/POK blends, both mechanical properties and water uptake increased with increasing PA6 content, while dual melting behavior associated with γ‐ and α‐form PA6 crystals was observed. By contrast, the blend with GMA‐grafted POK exhibited a remarkably more homogeneous morphology, lower equilibrium water uptake, and significantly improved long‐term mechanical stability. These improvements were further supported by melt‐rheological behavior and differential scanning calorimetry (DSC) analysis, confirming the effectiveness of reactive compatibilization.