Synthesis and characterisation of composite partially phosphorylated polyvinyl alcohol–aluminium phosphate as protective coating

Abstract

Partially phosphorylated polyvinyl alcohol–aluminium phosphate was synthesised through continuous stirring and condensation at 80°C. The compositions of the resulting phosphorylated polyvinyl alcohol–aluminium phosphate samples were varied, by adjusting the ion ratio and concentration of complex forming additives in the electrolyte solution. The as-synthesised phosphorylated polyvinyl alcohol–aluminium phosphate was then subjected to various chemical, thermal and structural characterisations. Fourier transform infrared studies show the bonding between phosphorylated polyvinyl alcohol and ALPO₄ at phosphate containing group. Differential scanning calorimetric studies show that T_g, T_m and degree of crystallinity increase as ALPO₄ filler was added to the system. Electrochemical impedance spectroscopy analysis shows good promising new inhibitor material for mild steel immersed in NaCl medium.

Keywords:

• Protective coating
• Composite
• Phosphate
• Interfacial bonding
• Thermal stability

Acknowledgements

This work was financially supported by UM PPP Grant (PS115-2010B and PV129/2012A) and UM High Impact Research Grant (UM. C/625/1/HIR/086). The authors also appreciate the allowance and leave by University Kuala Lumpur. The authors gratefully acknowledge both on financial support.