Nanofiller‐and basalt fiber‐reinforced recycled polyamide 6 hybrid composites

Abstract The influence of nanofillers (cellulose nanofibers (CNF) and halloysite nanotubes (HNTs)), and basalt fibers (BF) on the morphology, mechanical and thermal of recycled polyamide 6 (PA6) composites were investigated through scanning electron microscopy (SEM), mechanical testing, rotational rheometry, dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). CNF, HNTs and BF were relatively well‐dispersed in the PA6 matrix and the incorporation of these nanofillers and BF increased the strength of the matrix, which indicates a good dispersion of the nanofillers and BF. CNF and HNTs‐filled PA6 nanocomposites increased the tnsile strength by 14% and 6% compared to the neat PA6, respectively. The composites elongation at break decreased with nanofiller, BF and combined nanofillers and BF. The shear storage modulus values of PA6/20B5C, PA6/20B5H, and PA6/25B are significantly elevated compared to neat PA6, with increases of 3.7, 2.8, and 2.5 times, respectively, at an angular frequency of 100 rad/s. PA6/20B5H composites with 20 wt.% BF and 5 wt.% HNTs exhibited the highest storage modulus (9.5 GPa) from the DMA study. Thermal stability and ash content at 800°C increased with the incorporation of HNTs and BF. The DSC findings showed that the glass transition (T g ) and melting temperature (T m ) of the composites did not exhibit any notable changes when nanofillers and BF were added to the resin. The nucleation ability of PA6 was enhanced attributable to BF and hybridization of BF and nanofillers since the crystallization temperatures of PA6 in BF filled and hybrid composites were around 5°C greater than neat PA6. The results suggest hybrid composites with potential environmental characteristics and higher mechanical properties can be utilized in semi‐structural applications in automotive and construction as a sustainable and lightweight alternative to steel and other materials. Highlights The addition of HNTs, CNF, BF and hybridization of nanofillers with BF reduced the brittleness of PA6. Nanoreinforced and hybrid PA6 composites achieved higher storage modulus than neat PA6. Thermal stability and ash content increased with the incorporation of HNTs and BF. The hybrid composites have a higher complex viscosity compared to PA6. The sustainable hybrid composites can be utilized in automotive and construction industries.