| Abstract: | Polyurethane systems based on aliphatic diisocyanates were evaluated for suitability for use as underwater transducer encapsulants. A preliminary evaluation was performed to select the most promising urethane systems for further development. An investigation was then undertaken to determine the effect of compositional changes on the properties of these urethanes. The compositional parameters investigated were the soft-segment molecular weight, the prepolymer isocyanate content, the composition of the cure formulation, and the cure stoichiometry. These urethanes were subjected to long-term aging in seawater. It was found that this exposure did not significantly effect the physical or dynamic mechanical properties of the urethane. |
