Effects of Polyamide‐6 Bulk Plasma Treatment on Morphology, Crystallinity and Mechanical Properties of Microfibrillar Composites

ABSTRACT Plasma treatment is often used to alter chemical surface characteristics of fibers or polymers, improving dispersion of components and interfacial adhesion between incompatible constituents in composites. In this work, polyamide‐6 (PA6) was subjected to an atmospheric pressure plasma jet treatment during microfibrillar composite (MFC) processing. The plasma‐treated PA6 was investigated for its effects on morphology development and mechanical properties of MFCs. Following treatment, a blend of 70 wt.% low‐density polyethylene/30 wt.% plasma‐treated PA6 was compounded using a twin‐screw extruder. The extrudate was subjected to a drawing process using rollers, creating a necking zone, where microfibrils of the blend were formed. Scanning electron microscopy analysis revealed the formation of highly oriented PA6 microfibrils with approximately 0.8 μm diameter due to the fibrillization. MFCs manufactured from plasma treated PA6 exhibited reduction of form PA6 crystallinity and reduced LDPE transcrystallinity. The plasma‐treated PA6 enhanced both tensile modulus and strength of MFCs by 33.7% and 21.9% compared to those of the composite without plasma treatment. Morphology and surface energy analyses suggested possible compatibilization effects of plasma treatment, correlating with increased tensile strength of MFCs. These findings provided insights into the potential benefits of bulk polymer plasma treatment for producing high‐performance MFCs.