Development of Cardanol-Based Polyol via Click Chemistry and Crosslinking with Melamine Formaldehyde Resin for Coating Applications

摘要

The research work presented in this article deals with the synthesis of cardanol-based polyol and its curing with hexabutoxymethyl melamine(HBMM)for application in coatings.Cardanol-based polyol was prepared via thiol-ene click reaction using thioglycerol.Unsaturation present in the long chain of cardanol was successfully utilized to synthesize polyol via thiol-ene coupling.The reaction was carried out between cardanol and thioglycerol in the presence of Irgacure 184(photoinitiator)and 1,8-Diazabicyclo[5.4.0]undec-7-ene(catalyst)under UV light for 12 h at 80°C.After completion of the reaction,one mole of thioglycerol was successfully added across the double bond of a fatty chain of cardanol and confirmed by Fourier transform infrared spectroscopy(FTIR)and proton nuclear magnetic resonance spectroscopy and hydroxyl and iodine values were determined.Furthermore,the polyol thus prepared was cured with commercial HBMM in various proportions,such as 1:0.6,1:0.8 and 1:1,on an equivalent basis.The coatings were then characterized for mechanical,chemical,optical,thermal and anticorrosive properties.It was observed that coatings exhibited excellent performance properties as compared to that of its acrylic counterpart.