The effects of tension on the absorbance of water into neat and glass‐bead‐filled, cross‐linked polyester

Abstract The effects of tension on the absorbance of water at 60°C into neat and glass‐bead‐filled, cross‐linked polyester are reported. Experimental apparatus and procedure to determine water uptake for these materials subjected to three tensile stresses in the range of 0 to 30 percent of the breaking stress of the neat dry polyester are described. It was found, for bead‐filled samples, that a load of approximately 4.9 × 10⁶ N/m² caused the absorption level to increase by 30 percent over that of an unloaded sample. Tensile load was found to have no effect on the absorption characteristics of neat polyester. However, breaking stress was reduced to less than 15 percent of that in the dry neat material. Optical microscope examinations of damage at the fracture surfaces and at the sample cores indicate that the excess moisture uptake in bead‐filled samples was not due to microcrack formation.