Emulsification method for waterborne polyurethane
In the preparation of waterborne polyurethane, two emulsifying methods can be used, one is called external emulsifying method, the other is called self-emulsifying method.
At present, the self-emulsification method is more widely used.
Shear emulsification is a key step in the conventional synthesis of self - emulsifying waterborne polyurethane.
Shear emulsification involves adding water to a pre-polymer containing solvent, and the initial system is oil-in-water. With the continuous addition of water, the system has a phase transition point of oil-in-water.