Phosphorus Flame Retardants for Polymeric Materials from Gallic Acid and Other Naturally Occurring Multihydroxybenzoic Acids

Figure 4

¹H NMR spectra of phosphorus esters of methyl 3,5-dihydroxybenzoate. All the esters display good thermal stability (Table 5). Two esters, the diphenyl phosphate and the DOPO phosphonate, display decomposition onset temperatures above 300°C.