Donald Sturgeon used his PhD in engineering mechanics to evaluate the properties of Kevlar fibers especially for use in composite structures. Although the fiber was incredibly strong in tension, it had relatively poor performance in compression. The peculiar features of Kevlar fibers required that Kevlar re-enforced products had to be carefully engineered. Initially, DuPont hoped that Kevlar would find a large market as tire cord. When tire manufacturers opted for steel belts in radial tires, DuPont had to find other markets for its remarkably strong and light fiber.
Because Kevlar was difficult to make and process, the company had invested an unprecedented $500 million by the mid-1970s. Instead of one large market, DuPont had to develop many smaller applications for Kevlar. Sturgeon worked on developing and promoting weight-saving Kevlar composite materials to the aircraft industry. He was also involved in developing bullet-proof vests and non-cut fabrics. Through these extensive product development and marketing efforts, Kevlar eventually became a profitable product.