Hardness and wearing properties of SiO2-PMMA hybrid coatings reinforced with Al2O3 nanowhiskers

Some properties of SiO 2-PMMA hybrid coatings can be tailored by controlling the weight content of each component. For instance, hardness of SiO 2-PMMA hybrid coatings takes values between those of SiO 2 and PMMA, depending on the molar concentration ratio. Thus, these coatings are quite appropriated to be applied as antiscratch and abrasion resistant on polymeric materials such as acrylic. In this work we have evaluated the hardness and wearing properties of SiO 2-PMMA-Al 2 O 3 hybrid coatings deposited on acrylic substrates. The hybrid coatings were deposited by the sol-gel method from a precursor solution with a molar ratio 1:0.25:0.25 for tetraethil-orthosilicate (TEOS), methylmethacrylate (MMA) and 3-trimetoxi-silil-propil-methacrylate (TMSPM) as the coupling agent, respectively. Another set of hybrid coatings with additional 0.1 wt.% of Al 2 O 3 nanowhiskers in an identical precursor solution were also deposited on acrylic substrates. Hardness, creep and wearing properties of both types of hybrid coatings were evaluated by nanoindentation and nanoscratching. Complementary atomic force microscopy and optical transmission spectroscopy measurements were done in all the hybrid films studied.