Abstract: Fibers are conveniently coated with a uniformly thin and continuous elastomeric coating by contacting the fibers with a (1) a water-dispersed reactive polymer, (2) epoxy resin, and (3) curing agent; and wherein said water-dispersed reactive polymer is a composition comprising. (a) a lower molecular weight reactive polymer, (b) a select solvent, (c) a dispersing agent, and (d) water. The elastomeric films have a Tg value of about 0.degree. C. or below. The elastomer coated fibers are useful as strengtheners and impact modifiers for brittle materials such as epoxy resins.

Abstract: A composite comprising filler particles having a thin film of a reactive liquid polymer embedded in a polymeric matrix made by the method which includes the steps of mixing said reactive liquid polymer and said filler in order to provide a thin film of said reactive liquid polymer on said filler particles, mixing said coated filler particles with a polymeric matrix, and forming said composite.