On successive recycling of acrylonitrile butadiene styrene- melamine formaldehyde composite for sensing applications

In the past three decades, significant studies have been reported on successive recycling (SR) of acrylonitrile butadiene styrene (ABS) thermoplastic-based composites. However, SR of thermosetting polymers such as melamine formaldehyde (MF), bakelite, etc., is still a challenge in commercial terms, mainly due to high energy requirements. This study highlights the effect of SR for selected composition/ proportion of ABS (87.5% by wt.) and MF (12.5% by wt.) as a composite based on the mechanical, rheological, thermal and Fourier transmission infrared spectroscopy (FTIR) analysis. The study revealed that the tensile properties of ABS-MF composite deteriorate with each SR. The peak strength (PS) and modulus of toughness (MoT) (without recycling) were observed as 42.45 MPa and 1.60 MPa, which was reduced to 18.47 MPa and 0.1459 MPa after 03 SR. A continuous rise in melt flow index (MFI) was observed from 10.46 (without recycling) to 11.924 g/(10min) after 03 SR. Differential scanning calorimetry (DSC) analysis of samples supports the thermal stability of ABS-MF recycled composite after 03 SR. The printability of ABS-MF composite was also ensured after SR using the material extrusion (MEX) based 3D printing. FTIR analysis of ABS-MF composite shows a significant rise in transmittance of infrared radiation after SR, making the composite suitable for sensor applications. Further, the results of the impedance analyzer show an enhanced dielectric constant of ABS-MF composite after SR, which is ideal for sensor miniaturization.