Enhancing the Properties of PA6 and PA6/Ionomer Scraps Blend With CaCO ₃ Nanoparticles: Rheological, Mechanical, Thermal, and Morphological Evaluation

ABSTRACT This study investigated the effects of incorporating ionomer scraps and CaCO 3 nanoparticles on the rheological, mechanical, thermal, and morphological properties of neat polyamide 6 (PA6) and a PA6/ionomer scraps (80/20) blend. The ionomer formed an immiscible dispersed phase within the PA6, acting as an impact modifier; however, it reduced the strength, stiffness, and thermal stability of the PA6. Incorporation of CaCO 3 nanoparticles produced different effects depending on the matrix architecture. Rheology revealed distinct nanoparticle–matrix interactions: in PA6, nanoparticles behaved as lubricants at high frequencies and generated network‐like structures at low frequencies, while in the PA6/ionomer blend, they strongly interacted with the ionomer, disrupting ionic aggregates, decreasing viscoelastic moduli, and accelerating relaxation dynamics. CaCO 3 nanoparticles enhanced the tensile and flexural strength, stiffness, and heat deflection temperature (HDT), but reduced ductility. At higher concentrations, agglomeration limited these improvements. Notably, nanoparticles decreased impact strength in neat PA6 but promoted a synergistic effect, enhancing toughness, in PA6/ionomer blends. An optimal stiffness–toughness balance in PA6/ionomer blends was achieved with a minimal nanoparticle content of 1 wt% CaCO 3 , highlighting both performance gains and the sustainable valorization of ionomer scraps.