Silane coupling agent (SCA) pretreatment and polycaprolactone (PCL) coating for enhanced corrosion resistance for magnesium


To address the problem of rapid corrosion of magnesium (Mg) alloys, a biodegradable polymer film of polycaprolactone (PCL) with KH550 as silane coupling agent (SCA) was coated on Mg substrate. The effect of the coating was analyzed using electrochemical tests (potentiodynamic polarization curves and electrochemical impedance spectroscopy) and immersion tests (hydrogen evaluation tests and scratch tests). The electrochemical tests showed that the corrosion resistance was extremely improved (by nearly two orders for icorr and 1.04 V for Ecorr), and the immersion tests illustrated that the connection between PCL and Mg substrate was enhanced as well (especially in scratch tests), thus indicating significant improvement of the corrosion resistance of SCA-pretreated PCL polymer samples. In summary, SCA-pretreated PCL is a promising coating to decrease the degradation behavior of Mg substrate.

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This work was supported by the China National Nature Science Foundations (Grant Nos. 31070841 and 51705195) and China Postdoctoral Science Foundation (Grant No. 801161082418).

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Correspondence to Guangyu Li.

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Niu, J., Liu, H., Ping, X. et al. Silane coupling agent (SCA) pretreatment and polycaprolactone (PCL) coating for enhanced corrosion resistance for magnesium. J Coat Technol Res 16, 125–133 (2019).

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  • Magnesium
  • Biodegradability
  • Corrosion resistance
  • Polycaprolactone
  • Silane coupling agent