Thermal Degradation of Phosphorus Esters of Methyl 3,5- Dihydroxybenzoate

摘要

The development of nonhalogen, environmentally-benign flame retardants is of increasing interest. New materials that are not persistent in the environment, that do not bioaccumulate, and that do not pose a risk to human health are being sought. Phosphorus compounds derived from renewable biosources offer the best opportunity to meet these criteria. Alkylresorcinols are found in cereal grains, most notably wheat and rye. These compounds may readily be converted to 3,5-dihydroxybenzoic acid (in fact, this acid is a metabolite from the presence of these grains in the human diet). Simple Fischer esterification with methanol converts the acid to the corresponding methyl ester. The ester has been used as the base for the preparation of a series of phosphorus esters (both phosphonate and phosphate) which should display good flame-retarding potential. These compounds have been fully characterized using spectroscopic and thermal methods. Thermal stability and mode of degradation have been evaluated using thermogravimetry and infrared spectroscopy.