On Secondary Recycling of PVDF for 3D Printing of Functional Sensors: Mechanical, Flow, Thermal, and Dielectric Properties

Virgin polyvinylidene fluoride (PVDF) is widely used in numerous engineering and biomedical applications, hence requiring a scientific recycling solution to achieve the sustainable development goals of the United Nations. However, less has been stated on the effect of secondary (2 degrees) recycling of PVDF to ensure the 3D printing of functional sensors. This study compares virgin and 2 degrees recycled PVDF composite prepared by mechanical reinforcement (by wt.%) of 8% hydroxyapatite (HAp), and 2% chitosan (CS) with a single screw extruder (SSE) for the 3D printing of functional sensors. The 2 degrees recycled PVDF composite was compared with virgin PVDF based on mechanical, flow, thermal, surface characteristics, and dielectric properties. The study outlines that 2 degrees recycled PVDF composite may be used for the 3D printing of functional sensor prototypes with an improvement of Young's modulus (E) (45%), viscosity (122.6%), and surface roughness (Ra) (6.79%) for the selected composition. However, the modulus of toughness (MOT) was significantly reduced (88.37%). Overall thermal and dielectric properties have shown little variation after 2 degrees recycling.

Automated summary

Virgin polyvinylidene fluoride (PVDF) is widely used in engineering and biomedical applications, and there is a need for scientific recycling solutions to achieve sustainable development goals. This study compares the properties of virgin and secondary recycled PVDF composites and finds that secondary recycled PVDF composites can be used for 3D printing of functional sensor prototypes, although the modulus of toughness is significantly reduced.