ADVANCED MATERIALS & PROCESSES | SEPTEMBER 2024 10 RECYCLING UNSATURATED POLYMERS WITH OXYGEN AND LIGHT Researchers at The University of Akron, Ohio, developed a novel method to recycle unsaturated polymers such as rubber and plastics. The new process uses oxygen and light to help break down the polymers naturally. Since the 1950s, the mass production of plastics has resulted in the creation of approx- imately 8.3 billion metric tons of polymers. Most of these polymers have been discarded or incinerated, leading to significant environmental contamination. Only 600 million metric tons have been effectively recycled. The stability and durability of commercial polymers, particularly polyolefins—which constitute over half of global polymer production—present significant recycling challenges due to their hydrocarbon backbone. The new research focuses on introducing unsaturation to enhance the reactivity of these polymers, thus facilitating their recycling. Traditional methods for oxidative cleavage of alkenes, such as ozonolysis, epoxidation, and permanganate oxidation, while effective, often require environmentally unfriendly, energy-intensive conditions that are difficult to scale up. This study pioneers a controlled, efficient method for breakdown using a catalyst that, when activated under light, successfully breaks down the polymers at room temperature without requiring elevated temperatures or pressures. This research not only enhances our understanding of polymer degradation but also provides a practical, scalable solution for recycling unsaturated polymers. uakron.edu. STRONGER AND LONGER METALLIC MATERIALS A research team from Pohang University of Science and Technology (POSTECH), South Korea, and Northwestern University, Evanston, Ill., introduced a groundbreaking technology that enhances both high strength and high elongation in metallic EMERGING TECHNOLOGY materials. The new approach incorporates spinodal decomposition, where a solid solution spontaneously separates into two distinct phases, resulting in nanoscale structures with regularly arranged atoms. The scientists added copper and aluminum to an iron-based medium- entropy alloy to trigger periodic spinodal decomposition at the nanoscale. This process led to spinodal hardening, a phenomenon that enhances resistance to structural deformation. The resulting microstructure, with its uniformly arranged features, effectively distributes strain throughout the material. This distribution helps minimize localized deformation, thereby increasing overall strength while preserving elongation. Experiments revealed that alloys produced using the team’s method demonstrated superior structural integrity compared to traditional alloys, achieving a yield strength of 1.1 GPa. Remarkably, even with this increased yield strength, the alloy maintained nearly the same elongation (28.5%) as before. This advancement enables both improved strength and elongation. international.postech.ac.kr, northwestern.edu. A new tool called 4Pi from General Atomics (GA), San Diego, is helping to optimize the targets used in inertial confinement fusion experiments. Including the first ignition in December 2022, each of the five successful ignitions at the National Ignition Facility has used a target characterized by 4Pi. The tool combines up to eight instruments within one system, including robotics, automation, batch evaluation, and machine learning. ga.com. BRIEF A graphical depiction of a novel process for breaking down polymers. Courtesy of University of Akron. Analysis of spinodal decomposition and strengthening using nano-atomic-scale analysis. Courtesy of POSTECH.
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