Examination of poly(butadiene epoxide)-coatings on inorganic surfaces

The reactive coating of different inorganic model surfaces (dispersed SiO2- particles and planar Si/SiO2-, Ge/GeO2-, Al2O3- and TiO2-substrates) with p oly(butadiene epoxide) (PBDE) from organic solution is reported on. Further more, selected synthetic modification reactions at the coating surface are described. PBDE with different epoxidation degrees was synthesized by a pol ymer-analogous reaction using poly(butadiene) and peracetic acid. As surfac e sensitive methods FTIR-spectroscopy (Transmission, ATR, DRIFT), C-13 CPMA S NMR spectroscopy and wetting measurements were chosen. For the adsorption of PBDE onto dispersed SiO2-particles, a correlation was found between the total surface concentration and the degree of PBDE-epoxidation. As hints f or chemisorption the formation of covalent SiO-C-bonds on SiO2-particles wa s detected by C-13 CPMAS NMR and the loss of silanol groups was proven by D RIFT-spectroscopy. Evidence for covalent PBDE binding on planar inorganic s urfaces was obtained by means of ATR-FTIR-spectroscopy using a specific nu( CH) component at 2970 cm(-1), due to the epoxide group. Its intensity signi ficantly decreased due to a chemical reaction with the inorganic surface, w hereby the decrease was dependent on the kind of surface and the surface pr etreatment. Obviously, after the chemisorption unreacted epoxy groups of th e polymer coating remained, offering synthetic potential for further surfac e modification. Among a variety of modification reactions on PBDE coated su rfaces, the following were chosen: (1) hydrolysis to form diol functionalit ies; (2) further reaction with a diisocyanate; and (3) grafting of nucleoph ilic poly(ethylene glycol) (NH2-PEG) derivatives (3). (C) 1999 Elsevier Sci ence B.V. All rights reserved.