Aravind Dhandapani

Water resources are vital for humanity, but their quality has degraded in recent years due to increasing industrial activities. One significant issue is fluoride contamination, prevalent worldwide. Fluorides exist in combined states such as calcium fluoride, fluorapatite, and cryolite, originating from industrial processes like aluminum and fertilizer manufacturing. The World Health Organization warns against fluoride levels above 1.5 mg/L in drinking water due to health risks, including dental and skeletal fluorosis. Industrial activities also release fluoride-containing wastes into the environment, endangering ecosystems and human health. Overexposure to fluoride leads to disorders affecting organs including the kidneys, liver, and nervous system. Despite fluoride’s benefits in controlled doses, excessive intake causes health problems, as evidenced by rising dental fluorosis cases in Brazil. Thus, effective and affordable fluoride removal strategies are crucial. Various methods exist, including adsorption, membrane technology, ion exchange process, electrodialysis, and electrocoagulation. Regulation of fluoride levels in drinking water is imperative to safeguard public health from its detrimental long-term effects.

Short Sansevieria cylindrica fibre/polylactic acid composites (SCFP) were fabricated using a twin screw extruder followed by the hot press technique, with variations in fibre loadings of 10 wt%, 20 wt%, 30 wt% and 40 wt%. The thermal properties of SCFP were assessed through dynamic mechanical analysis (DMA), thermomechanical analysis (TMA), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Notably, the samples loaded with 40 wt% of fibre exhibited an increased storage modulus. In terms of loss modulus, the fibre-loaded samples displayed high values, indicating more heat is released during DMA experiment. Interestingly, the composite trend did not solely rely on increasing fibre loading, highlighting the intricate interplay between reinforcement and matrix crucial for determining viscoelastic properties across various temperatures. The TGA results revealed a decrease in inflection temperature with increasing fibre loadings, accompanied by a proportional rise in residues. The DSC thermograms indicated minimal differences in T_g, T_cc, and T_m values among composites with varying fibre loadings. However, neat PLA showed slightly higher values than the composites. On the other hand, reinforcing SCF into the PLA matrix promoted the crystallization of PLA by 1%–3% with the maximum degree of crystallinity of 25.4% obtained for 30 wt% of SCFP.

Polymers are ideal solutions for architects and constructors in the marine field who require materials that can achieve light and stable structures owing to their unique advantages. For instance, they possess a high strength-to-weight ratio, high wear resistance and fatigue strength, resistance to corrosion, ease of fabrication, and superior vibration damping behavior. These properties make polymers well suited for marine-based applications. However, polymers have their disadvantages, such as contributing to plastic pollution, which has a detrimental impact on the environment. In recent times, various concurrent methods have been employed to advance the future of polymers. This review explores (i) an overall view of polymers used in marine industries, (ii) a focus on reducing plastic wastage, (iii) challenges involved in recycling polymers and ensuring their sustainability, and (iv) the development of renewable plastics.