Mechanical upcycling of single-use face mask waste into high-performance composites: An ecofriendly approach with cost-benefit analysis.

The COVID-19 pandemic created an unprecedented demand for PPE, with single-use face masks emerging as a critical tool in containing virus transmission. However, the extensive use and improper disposal of these single-use face masks, predominantly composed of non-biodegradable plastics, has exacerbated environmental challenges. This research presents an innovative method for mechanically upcycling PPEs used in medical sectors i.e. single use face masks. The study investigates a facile approach for reclamation of infection-free and pure polypropylene (PP) plastic from discarded single use face masks (W-PP) and blends it with various vegetable oil percentages (5, 10 and 20 %), resulting in a versatile material suitable for various applications. Melt flow index, rheological behaviour, DSC and FTIR were employed to investigate the effect of vegetable oil/radical initiator through chemical grafting on W-PP properties. The results demonstrate significant enhancements in the tensile strength and modulus of W-PP when blended with vegetable oil and a radical initiator. There was a marked increase in tensile strength (33 %) and strain (55 %) compared to untreated W-PP, rendering W-PP both robust and flexible. Furthermore, we employed this upcycled W-PP in the fabrication of glass fibre-reinforced composites, resulting in notable enhancements in both tensile strength and impact resistance. The upcycled W-PP demonstrates excellent potential for various applications, such as sheet forming and 3D printing, where the non-brittleness of plastics plays a pivotal role in manufacturing high-quality products. The cost-benefit analysis of this approach underscores the potential of upcycling PPE waste as a sustainable solution to mitigate plastic pollution and conserve valuable resources. The applications of this upcycled material span a wide range of industries, including automotive composites, packaging, and 3D printing.

Deriving expert-driven seismic and wind fragility functions for non-engineered residential typologies in Batanes, Philippines.

Natural hazards inflict significant damage to dwellings in the Philippines where housing is often the most valued asset of households. Residential fragility functions estimate structural damage to mitigate risk but these are challenging to derive when empirical and analytical data are lacking, as is common in rural areas. Too often, conventional fragility estimates overlook the characteristics of informally built or non-engineered dwellings common in rural areas. We used a heuristic alternative of deriving fragility functions relying on experts' judgements to understand the housing performance of non-engineered residential typologies in the Province of Batanes in the Philippines. Drawing on field surveys in the Municipality of Itbayat, we identified and defined seven prominent typologies. Based on the Applied Technology Council's expert-driven method of deriving fragility functions, 18 experts estimated the damage states of these typologies against the impacts of earthquakes and typhoons which are the two most prominent hazards in the region. Our findings provide first-generation fragility functions for Batanes as a step towards more localised risk assessment in the Philippines. More broadly, these functions can be used for typologies identified beyond Batanes where similar structural characteristics are prevalent.

Microwave Attenuation of Graphene Modified Thermoplastic Poly(Butylene adipate-co-terephthalate) Nanocomposites.

With the widespread development and use of electronics and telecommunication devices, electromagnetic radiation has emerged as a new pollution. In this study, we fabricated flexible multifunctional nanocomposites by incorporating graphene nanoplatelets into a soft thermoplastic matrix and investigated its performance in attenuating electromagnetic radiation over frequency ranges of C (5.85⁻8.2 GHz), X (8.2⁻12.4 GHz), and Ku bands (12.4⁻18 GHz). Effects of nanofiller loading, sample thickness, and radiation frequency on the nanocomposites shielding effectiveness (SE) were investigated via experimental measurements and simulation. The highest rate of increase in SE was observed near percolation threshold of graphene. Comparison of reflectivity and absorptivity revealed that reflection played a major role in nanocomposites shielding potential for all frequencies while the low absorptivity was due to high power reflection at nanocomposite surface and thin thickness. Subsequently, effective absorbance calculations revealed the great potential of nanocomposites for absorbing microwaves, reaching more than 80%. Simulations confirmed the observed nanocomposites SE behaviours versus frequency. Depending on thickness, different frequency dependency behaviours were observed; for thin samples, SE remained unchanged, while for thicker samples it exhibited either increasing or decreasing trends with increasing frequency. At any fixed frequency, increasing the thickness resulted in sine-wave periodic changes in SE with a general increasing trend.