Abstract
Recently research workers at the laboratories of Monsanto Co. and DuPont Co. independently discovered organic fibers having specific tensile moduli greater than twice that of E-glass fibers. These fibers tend to have tensile strengths of at least 12 g/den and elongations-to-break of about 4%. Prior to the present discoveries, polyvinyl alcohol, polyethylene, rayon, and aromatic polyurea fibers had been made with specific moduli either equal to or approaching that of E-glass fibers; that work is reviewed briefly in the context of the recent advances. It was obvious on the basis of that early work that organic fibers which combined moduli at the 500 g/den level along with good thermal properties would have substantial utility for reinforcement applications where the density of glass and metal fibers is a drawback and where the very low extensibility of graphite fiber limits its usefulness.