Figure 1

Chemical structures of (a) perfluoropolyether alcohol (PFPE-CH₂OH), hexamethylene diisocyanate cyclic trimer (HDI), and 4-hydroxy benzophenone (BP). (b) Chemical structure of perfluoropolyether-benzophenone (PFPE-BP), synthesised from the isocyanate-alcohol reaction in (a). (c) FT-IR spectra of HDI, PFPE-CH₂OH, BP, and PFPE-BP.