Gurusamy Harichandran

Boric acid Catalyzed Efficient Synthesis of Symmetrical N,N' -Alkylidene Bisamides

Symmetrical N,N′-alkylidene bisamides were synthesized in excellent yield by condensation of aromatic aldehydes and amides in the presence of boric acid as a catalyst under thermal and neat microwave irradiation conditions. It is the first successful report of boric acid has been used as Lewis acid catalyst for the preparation of symmetrical N,N′-alkylidene bisamides. The remarkable advantages offered by this method are green catalyst, mild reaction condition, simple procedure, fast reaction and moderate to good yield of products.

Highly dispersive waterborne polyurethane/ZnO nanocomposites for corrosion protection

The interfacial interactions between surface-modified zinc oxide with oleic acid (OA-ZnO) and polymer matrix have important effects on the properties of nanocomposites. This zinc oxide nanoparticle was synthesized and characterized by various techniques such as field emission scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The water contact angle of waterborne polyurethane (WPU) nanocomposites is found to be increased with the addition of OA-ZnO compared with pure WPU. The corrosion protection of the polyurethane nanocomposites coatings on mild steel was assessed by potentiodynamic polarization and electrochemical impedance spectroscopy techniques. Coating with OA-ZnO in the WPU matrix showed the enhancement of resistance of mild steel to corrosion. This can be related to the surface modification by oleic acid which enhances the dispersion of nano-ZnO and improves the corrosion resistance of the WPU coating. Compared with unmodified ZnO nanoparticles, there were noticeable improvements in the hydrophobicity, corrosion protection, and uniform dispersion without agglomeration, and also improvement in the antisettling behavior when surface-modified ZnO nanoparticles with oleic acid (OA-ZnO) were used.