Structure-property relationships of some polyfluoroether coatings

A series of fluorinated coatings suitable for low temperature curing can be obtained by the proper combination of fluoropolyether macromers with the cyclic trimers of HDI and IPDI. In all cases they are characterised by general excellent surface properties (easy cleanability, and antigraffiti performances), good weatherability and chemical resistance. Mechanical properties can be adjusted by proper selection of the polyisocyanate or mixing (formulation) of the single resins, typically the IPDI macromer gives harder coatings with very short tack-free times, while the HDI-based materials have a better abrasion resistance and reactivity at low temperature. Many mechanical and surface properties of Fluorobase Z coatings can be correlated to their distinctive polyphase nature. In particular, the high molecular mobility of the fluoropolyether chains linked to polar functions and their enrichment in the top layer of the coating surface may be one of the reasons for the excellent stain release properties.