How to select Silicone surfactant for PU foam?

When selecting a silicone surfactant for polyurethane (PU) foam, you can consider the following factors:

• Silicone content 

Surfactants with higher silicone content have lower surface tension, which can increase the number of air bubbles in the foam. This can result in a smaller bubble size in the cured foam. 

• Siloxane backbone length 

Surfactants with longer siloxane backbones have higher film elasticity, which can lead to better foam cell stability and a slower drainage rate. 

• Application 

The surfactant can contribute to the foam’s physical properties depending on the application. 

l Structure 

The surfactant’s structure can be modified by changing the length of the PDMS hydrophobic backbone, the number, length, and composition of the pendent hydrophilic polyether chains. 

Silicone surfactants can be made up of a silicone base, polyethers, polyethylene oxide chains (EO), and polypropylene oxide chains (PO)