An investigation was conducted into plasma polymerization of transparent organosilica (SiOxCy) onto flexible transparent polyethylene terephthalate (PET) substrates for improving wear resistance. The plasma-polymerized SiOxCy with tetramethylsilane (TMS) and oxygen (02) gases in room temperature (23 degrees C) was proven to highly enhance the wear resistance from the completely worn of untreated PET substrates to no worn of TMS-oxygen plasma-polymerized PET substrates at higher discharge powers, while the wear test of 300 cycles at 300 g loading with a steel wool was applied. The performance of wear resistance on PET substrates was found to be strongly dependent on the surface characteristics of PET substrates. The surface hardness of PET substrates was determined by the pencil test. The surface morphology of PET substrate was observed by atomic force microscopy (AFM). The atomic compositions and chemical bondings of TMS-oxygen plasma-polymerized organosilicas were analyzed by means of X-ray photoelectron spectroscopy (XPS). (C) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 110: 2704-2710, 2008