Moisture Sorption and Diffusion in Kevlar 49 Aramid Fiber

摘要

Kevlar is being used increasingly as a reinforcement for fibrous composites. Since moisture affects the mechanical properties of organic matrix composites it is of importance to understand the sorption and transport of moisture in this material. The purpose of this work was to measure the sorption equilibrium of Kevlar with moisture and its diffusion coefficient as a function of concentration. Kevlar 49 has an unusually low diffusion coefficient compared to other polymers, so that the moisture transport in composites is governed by the organic matrix, or by other mechanisms such as microporosity, yet the equilibrium concentrations as a function of relative humidity are similar to most epoxy resins. (Author)