Blends of silyl-terminated polyethers and epoxides as elastic adhesives

Silyl-terminated polyethers (SILYL) can be blended with epoxy resins to form elastic adhesives. With appropriate formulation, the blend forms a stable curing emulsion in the presence of moisture, hardeners and compatibilizers. Small rigid epoxy particles are chemically linked by an elastic polyether phase. Strength (from the epoxy) and high impact resistance (from the polyether) are combined in a structure that shows high durability. Tuning of the mechanical properties can be done by adjusting the ratio of, and selection of the silylated polyether and the epoxy resin. Although typical lap shear strengths exhibited by the systems are generally still on the lower side (6-10 MPa), the initial mechanical strength is maintained after ageing and bonds do not break brittle. The system is at an experimental stage and only a few commercial applications have been realized so far. These applications are typically for the ones where large distortions can be expected, caused by temperature or physical load, such as tile bonding, sandwich panels, etc.