Solvent and catalyst-free synthesis of polyphosphates

Direct, efficient, solvent and catalyst-free synthesis of a series of polyphosphates was accomplished. The reaction involved a gas-liquid interfacial polycondensation between alkyl( aryl) phosphoric dichlorides and aromatic diols. The polyphosphates were characterized by IR, H-1 NMR, inherent viscosity, thermal analysis, X-ray diffractions and molar mass. Yields in the range 75-90% and inherent viscosities in the range 0.24-0.45 dl g (-1) were obtained. Polyphosphates were stable up to 170-250 degrees C, depending on phosphoric dichloride type. The X-ray diffraction patterns revealed that almost all the polymers were amorphous.