Materials researchers at the National Institute of Standards and Technology, Gaithersburg, Md., have demonstrated a simpler way of introducing reinforcing fibers into the matrix of a composite. First articulated more than 20 years ago by the late Nobel laureate Paul J. Flory, the concept results in a self-assembled composite that could be injected into molds, eliminating the costly steps now needed to incorporate fibers. The flexible polymer matrix used in the demonstration contains built-in fibers of a rigid polymer called Vectra, a material similar to Kevlar. So far the researchers have been able to more than double the strength of polyester in a composite containing only 0.2% Vectra. Even higher performance is being sought. Fang Qiao, Kalman Migler, and Charles C. Han, scientists in the Polymers Div. of the Materials Science and Engineering Laboratory, described the research in a paper presented at New York's Annual Technical Conference of the Society of Plastics Engineers.