Synthesis of poly(isobutyl-co-2,2,2-trifluoroethyl methacrylate) with 5,10,15,20-tetraphenylporphinato platinum(II) moiety as an oxygen-sensing dye for pressure-sensitive paint

Pressure-sensitive paint (PSP), which consists of luminescent molecules embedded in an oxygen-permeable polymer, has been developed for use in wind-tunnel experiments. To improve the PSP technique, a novel luminescent methacrylate monomer, 5-[4-(2-methacryloyloxyethoxycarbonyl)phenyl]-10,15,20- triphenylporphinato platinum(II), was synthesized and copolymerized with isobutyl methacrylate and 2,2,2-trifluoroethyl methacrylate to produce a dye-pendant copolymer (2). The introduction of 5,10,15,20-tetraphenylporphinato platinum(II) (PtTPP) dye into 2 was confirmed by ultraviolet-visible spectroscopy and extended X-ray absorption fine structure measurements. The extent of PtTPP dye incorporation in 2 was proportional to the molar fraction of the PtTPP-pendant methacrylate monomer in the feed. The oxygen-sensing property of 2 was compared with that of a PSP consisting of PtTPP dye embedded in poly(isobutyl-co-2,2,2-trifiuoroethyl methacrylate). Although the simple mixture of PtTPP and poly(isobutyl-co-2,2,2-trifluoroethyl methacrylate) showed a marked deviation from a single Stern-Volmer relation, novel copolymer 2 gave a highly linear Stern-Volmer plot. This was unequivocal evidence of dye conjugation on the oxygen-sensing polymer film.