Polythioether Urethane-Urea Elastomers Resistant to Fuels and Serviceable at Low Temperatures

摘要

Urethane-urea millable gums were prepared from polythioether diols or blends thereof with a tetrahydrofuran, ethylene oxide, allyl glycidyl ether terpolymer or a polyether containing epichlorohydrin. The presence of pendant unsaturation introduced by allyl glycidyl ether during diol preparation or glycerol allyl ether during gum preparation permitted these gums to be sulfur or peroxide cured. Although some vulcanizates of these elastomers exhibited good stress-strain properties, excellent oil and fuel resistance and fair low-temperature flexibility no one vulcanizate was able to meet all of these goals simultaneously. Zinc oxide markedly improved physical properties in sulfur-cured thioether vulcanizates. Hydroxy-polybutadiene resins were effective for introducing unsaturation into certain urethane-urea millable gums. (Author)