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A new super-strong fiber could revolutionize bulletproof vests and protective gear. Thanks to a breakthrough by researchers in China, the material is stronger, tougher and more effective at stopping bullets—while also being thinner—than the current gold standard material, Kevlar. Kevlar is made from aramid fibers, which can become brittle when scientists attempt to make them stronger. “Ultra-high dynamic strength and toughness are crucial for fibrous materials in impact-protective applications. However, the trade-off between strength and toughness is a persistent challenge in materials science,” the study authors wrote in the paper. “Achieving simultaneous breakthroughs in both properties demands innovative fabrication strategies. Polymer chains tend to slip during loading, which undermines the effective utilization of their high intrinsic mechanical properties, thereby limiting the strength and toughness of polymer fibers. "To address this issue, we developed an effective strategy that regulates the orientation of carbon nanotubes within fibers to inhibit chain slippage.” By regulating the orientation of long carbon nanotubes within fibers, the team fabricated “carbon nanotube/heterocyclic aramid composite fibers with a dynamic strength of 10.3 GPa and a dynamic toughness of 706.1 MJ m−3.” The new fiber type—made from combining these two materials and ensuring they were straight and parallel with each other to lock them together—is strong, stiff and thinner than a human hair. The researchers attribute the “ultra-high dynamic performance” to the “inhibited slippage” and “remarkable breakage of aramid chains under high-speed impacts." These high-speed tests included ballistic tests like those used for body armor, which the fiber performed better in. “These behaviors are due to the improved alignment of polymer chains, reduced porosity, and thus enhanced interfacial interactions and load transfer efficiency therein induced by aligned long carbon nanotubes and multi-stage drafting," the authors wrote. “This work provides a fresh understanding and a feasible route for utilizing the intrinsic mechanical performance of polymer chains at the macroscale.” If the new fiber is adopted, bullet proof vests and protective gear could soon be far more safe and effective. Newsweek has reached out to the researchers for additional comment. Do you have a tip on a health story that Newsweek should be covering? Do you have a question about the new fiber? Let us know via health@newsweek.com. Reference
