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The ongoing COVID-19 pandemic has resulted in an unprecedented form of plastic pollution: personal protective equipment (PPE). On the eve of the COVID-19 pandemic, there is a tremendous increase in the production of plastic-based PPE. To control the spread of the virus, face masks (FMs) are used as primary PPE. Thus, the production and usage of FM significantly increased as the COVID-19 pandemic was still escalating. The primary raw materials for the manufacturing of FMs are non-biodegradable synthetic polymers derived from petrochemicals. This calls for an urgent need to develop novel strategies for the efficient degradation of plastics. Furthermore, most of these masks contain plastic or other derivatives of plastic. The extensive usage of FM generates millions of tons of plastic waste for the environment in a short span of time. However, their degradation in the environment and consequences are poorly understood. Therefore, the potential impacts of disposable FM on the environment and human health during the COVID-19 pandemic are clarified in the present study. Despite structural and recalcitrance variations, lignocellulose and plastic polymers have physicochemical features, including carbon skeletons with comparable chemical bonds as well as hydrophobic properties in amorphous and crystalline regions. In this review, we argue that there is much to be learned from termites by transferring knowledge from research on lignocellulose degradation by termites to that on plastic waste.

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Non-woven disposable masks play a unique role in reducing the COVID-19 pandemic threat in transmission between people, but the huge amount of disposable non-woven masks generated every day are currently posing a serious challenge to our environment on a global-wide scale. In line with this emerging problem, a series of recycling processes were designed and conducted to evaluate the performance of material recovered from those waste masks for potential use in three-dimensional (3D) printing. A composite filament from recycled polypropylene (rPP) and an additive material, glass fiber (GF), was fabricated by melt-blending processing followed by single-screw extrusion. A variety of material properties, including the chemical/mechanical/microstructure property, thermal stability, printability, rheology performance, and geometrical accuracy toward GF/rPP composite filaments, were comprehensively analyzed. Our results demonstrated that two important mechanical properties, the compression strength and the tensile strength, to a 3D printed object by fused deposition modeling (FDM) from the GF/rPP composite were significantly higher than that of a FDM 3D printed object from GF/polypropylene composites. The specific warpage parameter ( Wsp) and the surface roughness ( Sa) for a 3D printed object from the GF/rPP composite at 30 wt% GF additive would have printing accuracy of 0.54% ± 0.0014 and 21.1 ± 0.76 µm, respectively, and no clogging phenomenon was observed in the printer nozzle channel during the printing processing, suggested that this recycling method for a large number of non-woven waste masks was potentially applicable in serving as a FDM 3D printing material.

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