Sealants
Slicones
- provide superior elasticity to -68 oC, resistance to compression set (80-100% recovery)
- good uv and ozone resistance
- ability to bond to most clean surfaces without a primer
- low tear strength, poor abrasion resistance and to organic fluids
- high water vapor-transmission rate
- poor bonding to nonsilicone sealants
Polysulfides
- provide better fuel resistance than any other elastometric sealant
- second only to polyurethanes in alkaline chemical resistance and to butyls in resistance to permeation by water vapor
- strong mineral acids attack only at high concentrations, organic acids more destructive