From the archives: The 1970s

In 1970, C&EN published a news article on two new “tire fibers” that DuPont had introduced at a recent Akron Rubber Group meeting. They were so new that they weren’t even given trademarks yet but were code-named Fiber A and Fiber B. Fiber A had a higher melting point than nylon 6,6 and was suitable for car and truck tires. Fiber B, DuPont executive John W. Hannell boasted, had “far greater strength and modulus as well as better dimensional stability than any other organic fiber available.” That fiber, the company predicted, could even be used in airplane and off-road tires. But Fiber B had a brighter future ahead of it than just tire cord. DuPont would soon give Fiber B one of the most recognizable trademarks in all chemistry: Kevlar. The p-aramid fiber took off in applications like aerospace, cables, personal protective equipment, and of course, bullet-resistant body armor. Kevlar was made possible by DuPont chemist Stephanie Kwolek’s groundbreaking work in aromatic polyamides. In 1964, Kwolek was tasked by DuPont to come up with new high-performance fibers. She worked out a synthesis for high-molecular-weight poly(p-aminobenzamide). The resulting solution was cloudy, not clear or translucent, and had a low viscosity—both odd properties for a polymer solution. What Kwolek didn’t realize at that moment was that she had created a liquid-crystal solution. Spun into a fiber, the material had exceptional properties. This work led to poly(p-phenyleneterephthalamide), which would bear the Kevlar name.