Abstract
This paper investigated the influence of chemical damage of polymer electrolyte membrane (Nafion^[○!R]) on fracture strength in Polymer Electrolyte Fuel Cell. Nafion^[○!R] NR211 was damaged for 24 h by using a Fenton's accelerated aging experiment. The fracture strength of Nafion^[○!R] was evaluated by essential work of fracture (EWF). EWF was derived by using double edge notched tensile (DENT) test. DENT test was conducted for fresh and damaged Nafion^[○!R] under four conditions: 30℃ 50 %RH, 30℃ 100 %RH, 80℃ 50 %RH and 80℃ 100 %RH. The fracture surface was observed by using Scanning Electron Microscope (SEM). The results showed that the fracture strength of Nafion^[○!R] was decreased by chemical attack; decreasing rate was about 41 % at room temperature and normal humidity, about 79 % at high temperature and normal humidity, about 87 % at high temperature and high humidity. Moreover, the fracture surface revealed that the brittle fracture with crazing was occurred on the damaged Nafion^[○!R] at normal temperature and high humidity.
