Abstract
Dumbbell-shaped coupons of four elastomers including vinylidene fluoride (VF) and hexafluoropropylene (HFP)-containing elastomer, red rubber, ethylene propylene diene monomer (EPDM), and Buna N Nitrile were soaked in solutions containing either 100 ppm or 1% DBU (1,8-diazabicyclo[5.4.0]undecene-7) at a temperature of 200°F (93°C) for periods of 7 days and 30 days. Samples were tested before and after the soak periods to evaluate effect of their exposure to DBU-containing solutions on weight change, tensile strength at breakage, percentage elongation at breakage, and surface hardness. The soaked coupons were visually inspected for visible material degradations such as cracking or swelling that may have occurred during the soak in DBU solutions. Information gathered was used to evaluate and compare the performance of all four elastomers when exposed to DBU at elevated temperatures for extended periods. Results indicated that the VF+HFP-containing elastomer was affected the most from the soak in DBU solutions after both test periods. Marked reduction in the strength and elasticity of the VF+HFP-containing elastomer was observed and was accompanied by visible signs of decomposition. Buna N Nitrile had the greatest increase in weight after exposure to 1% DBU for 7 days and 30 days; however, only a small reduction in tensile strength was observed. The other two elastomers (EPDM and red rubber) showed only minor changes in tensile strength and elasticity after the soak in DBU solutions.
