Fibrillisation and Mechanical Properties of Plasma‐Treated Modification LDPE/PA6 Microfibrillar Composites

ABSTRACT

Extensive research has established the relationship between processing conditions, morphology, and resulting properties of microfibrillar composites (MFCs). This study investigated the effects of atmospheric pressure air plasma jet (APPJ) treatment during melt blending on the viscosity ratio and dispersion of polyamide 6 (PA6 30 wt %) droplets within a low‐density polyethylene (LDPE 70 wt %) matrix. Various draw ratios (3, 5, 6, and 8) and drawing temperatures (140°C, 160°C, and 180°C) were selected to explore the influence on the fibrillisation of the PA6 reinforcement and mechanical properties. Plasma treatment introduced carbonyl groups in LDPE and LDPE‐PA6 blend, enhancing interfacial adhesion and compatibility, and significantly reduced the viscosity ratio from 5.41 to 0.017 during melt blending, resulting in more homogeneous PA6 dispersion and a reduced droplet‐size heterogeneity. Although the MFC's tensile strength increased up to 500% with a draw ratio of 6, no substantial difference was observed between plasma‐treated and untreated blends. However, plasma treatment increased the stiffness and crystallinity of compression‐molded MFCs by 18% and 10%, respectively, at a draw ratio of 6. A drawing temperature of 160°C produced highly oriented microfibrils with an average diameter of approximately 0.097 μm and the best overall mechanical performance.