Ceramics-Silikáty 59, (4) 341 - 347 (2015)

Novel preceramic polymers were synthesized by hydroboration reaction and pyrolyzed under continuous nitrogen flow to obtain boron containing silicon oxycarbide (SiBOC) ceramics. The preceramic SiBOC polymers were synthesized with different cyclicsiloxane/borane molar ratios. Structure of the SiBOC polymers and transformation of them to the SiBOC ceramics investigated by Fourier Transform Infrared spectroscopy (FT-IR), Thermogravimetric analysis (TGA), X-ray Diffraction (XRD) technique and Scanning Electron microscope (SEM). Since the cyclicsiloxanes used in smaller sizes according to literature, variations were observed in structure of obtained polymers and ceramics. During the pyrolysis of polymers, loss of the carbon was little. The transformation from amorphous form to the β-SiC crystal was achieved above 1200^oC and consequently thermally stable SiBOC ceramics were obtained at higher temperatures. Antibacterial activity of SiBOC polymers were evaluated by disc diffusion method against E. coli ATCC 25922- for the first time. The new polymers inhibited the growth of Gram-negative bacteria well enough.