Thermal behavior of phosphorus derivatives of hydrogenated cardanol

Hydrogenated cardanol and its derivative, butylated cardanol, can be phosphorated using diethyl chlorophosphate or diphenyl chlorophosphate in chloroform to give ethyl or phenyl phosphates. The resulting products were characterized by GC–MS, FT-IR spectroscopy and their thermal behavior was evaluated by thermogravimetric analyses such as TG and DSC. Thermal parameters such as number of degradation steps, initial (Ti) and maximum (Tmax) degradation temperatures, loss of mass (∆m (%)) and the integral procedure decomposition temperature (IPDT) were determined. TG curves of ethyl and phenyl phosphates showed that phenyl phosphates are more stable than ethyl phosphates probably due to the high stability POCaromatic bond. In ethyl phosphates, the effect of ethoxy group (OC2H5) reduces thermal stability. For the phenyl phosphates, DSC measurements presented peak temperatures about 465.8 °C suggesting the possibility of application of these compounds as antioxidants for petrochemical products, for example lubricant oils.