POLYURETHANE MATERIALS USING ALIPHATIC DIISOCYANATES FOR PASSIVE ISOLATION IN BUILDINGS APPLICATIONS
During the past decade, a lot of effort has been spent to develop strategies to mitigate the damaging effects of earthquakes. This work has been directed at both civil structures and nuclear facilities. Polyurethane elastomers (PEs) based on polyethylene adipate diols and aliphatic diisocyanates can be used as passive isolation bearings in buildings applications. In the present study, polyesterdiol and 1,6-hexamethylene diisocyanate (HDI) have been used in polyurethanes, using glycerine, ethylene or diethylene glycols as chain extenders. Effect of varying the concentrations of diisocyanates and structure of chain extenders on PEs has been discussed with reference to mechanical properties. IR and thermal analysis techniques (TGA) were used for characterization. The results reveal that aliphatic character of diisocyanates lowers the temperature required to achieve the flexibility in the polymer. Based on their mechanical properties, PEs have great potential for applications where wind and earthquake loads resistance, dynamic-to-static stiffness ratio and vertical and lateral load characteristics are required.