application and advantages of polyurethane catalyst dmdee in surface treatment of medical devices 1. introduction: from “behind the scenes” to “before-stage star” in the field of modern medical devices, there is a seemingly inconspicuous but indispensable chemical substance – the polyurethane catalyst dmdee (n,n,n’,n’-tetramethyl-1,4-butanediamine). it is like an unknown “behind the scenes hero” who plays...