3D printing polypropylene composites reinforced with functionalized halloysite: Balance between stiffness and impact resistance

Abstract In this work, a new nano‐reinforced polypropylene filament was produced and fabricated by 3D printing to create a nanocomposite with a good balance between stiffness and impact resistance properties. Nanocomposite filament with 0.5, 1.0, and 1.5 wt% of functionalized halloysite nanotubes was prepared. The chemical modification was carried out to obtain a reinforcement that could act as an improved β‐nucleating agent and characterized by infrared spectroscopy. The spectrum showed the appearance of two new bands at 1571 and 1410 cm −1 , which could indicate an interaction between the pimelic acid molecules and the oxygenated surface of the halloysite nanotubes. Energy dispersive X‐ray spectroscopy analysis confirmed a good dispersion of the modified reinforcement along the surface of the nanocomposite filament. Wide‐angle X‐ray scattering and differential scanning calorimetry analyses showed the improvement of the β‐nucleating ability of the halloysite nanotubes through new chemically functionalized, obtaining percentages of β‐crystal of 80% for the nanocomposite reinforced with 0.5 wt%. The dynamic mechanical analysis showed that the 3D‐printed functionalized nanocomposites presented higher storage and loss modulus (an increase of 148% and 122%, respectively). Finally, the impact strength properties increased by 90%, 108%, and 21% for the functionalized nanocomposites with 0.5, 1.0, and 1.5 wt%, respectively. Highlights Chemical functionalization of a natural reinforcement as a ‐nucleating agent. 3D printing polypropylene nanocomposites with enhanced properties. Good balance between impact and stiffness properties of nanocomposites.