Effect of moisture on the tensile properties of poly(hydroxy eater ether)

The effects of moisture and strain rate on the tensile properties of poly(h ydroxy eater ether) (PHEE) were investigated. Water was shown to act as a p lasticiser which lowered the room temperature tensile strength and modulus. The strain at failure increased with increasing water content and a change in the mode of failure was observed. Brittle failure occurred when the moi sture content was low. As the sorbed water content increased, the samples n ecked and extensive plastic deformation resulted. The samples deformed in a quasi-homogeneous manner at testing temperatures close to the glass transi tion temperature. The yield stress decreased with moisture content and incr eased with strain rate. For samples which deformed in a ductile manner, the variation in the yield stress with strain rate was well described using th e Eyring model. The effect of water content on the yield stress was shown t o be analogous to the effect of temperature. (C) 2001 Published by Elsevier Science Ltd.