Phosphorus-containing telechelic polyester-based ionomer: Facile synthesis and antidripping effects

The ionomer concept was introduced to the field of flame-retardant polyesters for the first time. The ionic monomer, sodium salt of 2-hydroxyethyl 3-(phenylphosphinyl)propionate (SHPPP), was synthesized by selective esterification of 3-(hydroxyphenylphosphinyl)propionic acid with ethylene glycol, followed by neutralization with sodium carbonate anhydrous. SHPPP was characterized with H-1, C-13, and P-31 NMR spectroscopy, Fourier transform infrared spectroscopy, and X-Ray photoelectron spectroscopy. Poly(ethylene terephthalate)-based ionomers containing terminal units derived from this ionic monomer, were synthesized by melt polycondensation. The chemical structure of the ionomers was characterized with H-1, C-13, and 31P NMR spectroscopy. The effects of SHPPP on the thermal properties and melting behaviors of the ionomers were investigated by thermogravimetric analysis and differential scanning calorimetry. The flammability of the ionomers was characterized by the limiting oxygen index test. The test results show that the ionomers themselves possess both excellent flame retardancy and antidripping properties. (C) 2008 Wiley Periodicals, Inc.