ENVIRONMENTAL-STRESS DEFORMATION OF POLY(ETHER ETHER KETONE)

The sorption of water in poly(ether ether ketone) (PEEK) from aqueous solutions containing a small (5 x 10(-5) mol fraction) of three differ ent surfactants was investigated as a function of external tensile str ess. One of the surfactants, a polyoxyethylene alcohol, exhibited a st rong stress effect, producing an increase in water solubility of nearl y an order of magnitude for stress levels > 40 MPa in amorphous PEEK. The solubility and diffusion coefficient for the sorption of water int o PEEK were also investigated. The critical stress (strain) for water sorption, the rate of wetting, and surface deformation morphology were determined. In these aqueous solutions, the primary factor affecting stress-enhanced sorption is a reduction in surface energy and associat ed surface mobility. (C) 1997 John Wiley & Sons, Inc.