| abstract |
Fluorinated oligourethanes, having number average molecularnweight lower than or equal to 9,000, having a branched structure,nformed of the following monomers and macromers:n a) aliphatic, cycloaliphatic or aromatic polyisocyanates, b) heterofunctional hydrogenated monomers havingngeneral formula:n X 0 -(CR 1 A R 2 A ) b -Y 0 none or more of the following compounds: c) bifunctional hydroxyl (per)fluoropolyethers (PFPE diols)nhaving number average molecular weight in the rangen400-3,000, e) monofunctional hydroxyl (per)fluoropolyethers ornmonofunctional hydroxyl (per)fluoroalkanes (e'), havingnnumber average molecular weight in the range 300-1,000, nand optionally the following compunds: d) heterofunctional monomers, d I ) hydrogen-active compounds, capable to form bonds with thenNCO functions stable at the hydrolysis but weak at heat. |