Additive manufacturing of a polyamide 12 and silica nanocomposite: A route for the reusability of a thermoplastic selective laser sintering powder

A route for the synthesis and additive manufacturing of a polymer-silica nanocomposite with polyamide 12 (PA12) polymer as the matrix material and silica nanoparticles as the reinforcing filler, has been presented in this work to enable the reusability of PA12 powder waste. PA12 powder formerly has been used in selective laser sintering to manufacture customized implants and lightweight structural components in the medical, automotive, and aerospace industries. Nano-sized silica particles with varying dispersibility have been used as a filler with different weight contents (1% and 3%) in PA12 composites. These nanoparticles were coated with polyvinyl alcohol to achieve uniform dispersion. The nanocomposite filaments have been extruded and the final manufactured part has been printed by fused filament fabrication. SEM, EDX, and PSD showed that nanoparticles were homogeneously distributed, and the fabricated structures were crack-free for adapted processing parameters. DSC, FTIR, and mechanical testing at different processing stages of the material showed enhanced mechanical and thermal properties compared to waste PA12. All manufactured composite structures showed an increase in tensile modulus and tensile strengths up to 30%. This approach can be used to improve the properties of PA12 waste and its further utilization for various applications.Highlights Organic solvent-free method for the reinforcement of waste polyamide 12 material. Comprehensive insight into the dispersity of nano-silica in polymer matrix. Increase of up to 30% tensile strength for 3 wt% nano-silica loading.