The reactive coating of different inorganic model surfaces (dispersed SiO2- particles and planar Si/SiO2-, Ge/GeO2-, Al2O3- and TiO2- substrates) with poly(butadiene epoxide) (PBDE) from organic solution is reported on. Furthermore, selected synthetic modification reactions at the coating surface are described. PBDE with different epoxidation degrees was synthesized by a polymer-analogous reaction using poly(butadiene) and peracetic acid. As surface sensitive methods FTIR-spectroscopy (Transmission, ATR, DRIFT), 13C CPMAS 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 for chemisorption the formation of covalent SiO–C-bonds on SiO2-particles was detected by 13C CPMAS NMR and the loss of silanol groups was proven by DRIFT-spectroscopy. Evidence for covalent PBDE binding on planar inorganic surfaces was obtained by means of ATR-FTIR-spectroscopy using a specific ν(CH) component at 2970 cm-1, due to the epoxide group. Its intensity significantly decreased due to a chemical reaction with the inorganic surface, whereby the decrease was dependent on the kind of surface and the surface pretreatment. Obviously, after the chemisorption unreacted epoxy groups of the polymer coating remained, offering synthetic potential for further surface modification. Among a variety of modification reactions on PBDE coated surfaces, the following were chosen: (1) hydrolysis to form diol functionalities; (2) further reaction with a diisocyanate; and (3) grafting of nucleophilic poly(ethylene glycol) (NH2-PEG) derivatives (3).
Köthe, M., M. Müller, F. Simon, H. Komber, H.-J. Jacobasch, H.-J. Adler
Colloid. Surface. A