DuPont chemists who developed Kevlar, 1970s. From left, they are US chemists Paul W. Morgan (1911-1992), Stephanie Louise Kwolek (1923-2014) and Herbert Blades. The unit structure of Kevlar is on the blackboard behind them. Kwolek spent 40 years working as a research chemist at the DuPont Company. In 1965, working with Morgan and Blades, she developed the first in a family of liquid crystal polymers that provided the basis for the Kevlar brand fibre. Kevlar has a high tensile strength-to-weight ratio, five times stronger than steel. Morgan had joined DuPont in 1941, and Blades started work with DuPont in 1954. Photographed in the 1970s.