Abstract
Novel phosphorylated cardanol molecules based on phosphonate (PO3CR) and phosphate (PO4CR) functions have been synthetized. Those molecules have two main actions which are described in this article: the reduction of volatile organic compounds (VOC) and the development of flame retardant (FR) properties conferred to alkyd resin coatings. Phosphorylated cardanol compounds have been successfully grafted by covalent bonds to alkyd resins thanks to auto-oxidative reaction. The impact of the introduction of PO3CR and PO4CR on the film properties such as drying time and flexibility have been studied and the thermal and flame retardant properties through differential scanning calorimeter, thermogravimetric analysis and pyrolysis-combustion flow calorimeter. These studies underscored an increase of the thermal stability and FR properties of the alkyd resins. In cone calorimeter test, the lowest pHRR was obtained with 3 wt% P of phosphate-cardanol and exhibited a value of 170 KW.m-2 , which represented a decrease of almost 46 % compared to the POxCR-free alkyd resins. Moreover, a difference about the mode of action between phosphonate and phosphate compounds has been highlighted. The most effective coating which combined excellent FR properties and good coating properties has been obtained with 2 wt% P of phosphate-cardanol. Indeed, the film properties were closed to the POxCR-free alkyd resin and the pHRR decreased of 41 % compared to the reference alkyd resin.