SYNTHESIS OF LOW TEMPERATURE OIL RESISTANT URETHANE ELASTOMERS.
Final rept. for 1 Jul-31 Dec 63 and 15 May 64-15 May 65,
WYANDOTTE CHEMICALS CORP MICH
Pagination or Media Count:
The preparation of polyether urethane elastomers is described, and the effect of variation in polyether backbone, formulation and processing on their properties evaluated. Special attention was given to attaining elastomers with low temperature flexibility at -55C. combined with 10 ASTM No. 3 oil absorption when immersed 70 hours at 100C. By using high molecular weight polyether polyols prepared from approximately equal molar quantities of ethylene oxide and tetrahydrofuran, these two target properties were achieved with only a slight compromise in tensile strength requirements. The key factor in the preparation of elastomers with good oil resistance was the concentration of the polar linkages and crosslinks between long, flexible polyether chains. The low temperature flexibility was attained by using the ethylene glycol-tetrahydrofuran polyols to provide the long, flexible polyether chains. Cast urethane-urea elastomers have been prepared from blends of high molecular weight polyethers and polytetramethylene ether glycols which meet the mechanical strength, compression set at 100C. and low temperature flexibility at -55C. requirements of the contract. However, the oil resistance requirement was not satisfied. Author