Development of Polyurethanes with Improved Flame Retardant Properties based on Alkoxylated Glycerol Phosphate

摘要

The synthesis of bifunctional polyols using glycerol phosphate disodium salt by means of anionic polymerization was achieved. The use of a phosphate salt as initiator allows us to obtain polyols with phosphate groups in its backbone not previously described. New environmentally friendly flame-retardant coatings were developed employing this phosphorylated flexible polyether polyols. Thermogravimetric studies (TGA) revealed that the initial decomposition temperature of the phoshorylated polyols decreases with increasing phosphorus content. The residue in the TGA of the phosphorylated coating was higher than that of the reference coatings in thermo-oxidative conditions and increased with the phosphorus content in the polyol. The incorporation of 0.33% phosphorus increases the values of the Limiting Oxygen Index (LOI) from 23 (reference coating) to above 28 (phosphorylated coating). The SEM microphotographs of char revealed that the presence of phosphorus in the polyurethane structure improves the char structure and flame retardancy of the coatings.