Silyl-terminated polyether and related silyl-modified polymers cure like silicones with moisture but have an organic backbone, so they can be painted and do not leave silicone contamination. They bond well to many substrates, often without primers, and are used on facades, windows and EIFS. The trade often calls them hybrids or MS sealants.
Painter needs to coat over it, so use the STPE, not the silicone.
Also heard as
- hybrid sealant
- MS polymer
- silyl-modified polymer
- SMP
Related terms
Polyurethane sealant
A tough, paintable elastomeric sealant used widely on concrete, masonry and traffic joints.
Silicone
A sealant with a silicon-oxygen backbone, prized for UV resistance and high movement capability.
Sealant
A material that fills a joint or gap to stop water and air, while accommodating movement.
Modulus
How stiff a cured sealant is, meaning how much force it pulls on its bond faces when stretched.