Thermal Stability of the bis-DOPO Ester of N-Phenyl-4,4-di(4- hydroxyphenyl)pentanamide

摘要

Recent concerns about sustainability and environmental quality have stimulated the development of nontoxic polymer additives. In particular, non-halogen materials which are not stable in the environment and do not bioaccumulate are being sought. Additives generated from renewable biosources are generally less toxic and more biodegradable than their petrochemical counterparts. Further, the cost of these materials is independent of fluctuations in the petrochemical markets. Diphenolic acid [4,4-di(4-hydroxyphenyl)pentanoic acid] may be generated from biomass-derived levulinic acid. It is trifunctional with two hydroxyls and a carboxyl group and can be readily converted to compounds with useful properties. Treatment with thionyl chloride followed by aniline provides the corresponding amide. The resulting diol may be converted to the bis-ester of 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO) which should function as a good flame retardant. This compound has been fully characterized using spectroscopic and thermal methods. Thermal stability has been assessed using thermogravimetry and infrared spectroscopy.