| abstract |
Fluorinated polyurethanes and polyurethane-ureas, of heat-processable, elastomeric type, constituted by rubber-like blocks and hard blocks, comprising segments derived from: (a) a macroglycol or polybutadiene-diol; (b) a perfluoropolyether-diol of formula HO(CH2CH2O)n-CH2-Q-CH2-(OCH2CH2)nOH wherein Q is a perfluoropolyether chain and "n" is comprised within the range of from 1 to 5; (c) an aromatic, aliphatic, or cycloaliphatic diisocyanate; and (d) an aliphatic, cycloaliphatic or aromatic diol or diamine, containing from 2 to 14 carbon atoms. They contain from 4 to 30% by weight of fluorine, from 10 to 60% by weight of hard components, with the molar ratio of rubber-like components (a): (b) comprised within the range of from 2 to 20. At least 80% of rubber-like segments deriving from (b) component are connected, at least at one of their sides, through a segment deriving from (c) component, with a rubber-like segment deriving from (a) component. |