I copied some information for you. I'm not sure myself. I can't tell the mechanism.
Hydrogen atoms and oxygen atoms in urea can combine with hydrogen atoms and oxygen atoms in polymer hydrogen bonds, thus breaking the hydrogen bonds.
Polymerization of disodium ethylenediamine tetraacetate (EDTA) to shield the inhibition of heavy metal ions.
That is to say, urea can accelerate dissolution, and if PAM polymerizes, adding urea can inhibit cross-linking.
I hope I can help you.
By the way, wait for the experts to answer and talk about the mechanism. I can see it myself.