Table of Contents Introduction Phosphoric Anhydride & Polyphosphoric Acid      Phosphoric Anhydride        Polyphosphoric Acid Reactions      Phosphoric Anhydride and Alcohols The Polyphosphate Content of Polyphosporic Acid (PPA) Reaction Conditions Hypophosphorous Acid & Color Formation Materials of Construction Trade Names DOT Rating Phosphate Esters & Their Acid Values (AV)* Analytical Procedures      Determination of Acid Number and Percent Phosphoric Acid, Monoester and Diester in Phosphate Ester      Determination of Total Nonionics by Ion Exchange Tables, Figures & Charts Table 1: The Hydrolysis Products of Phosphoric Anhydride Table 2: Molar Equivalent Masses, Phosphoric Anhydride: (OH) Figure 1: The Molecular Structure of Phosphoric Anhydride Figure 2: The  Reaction of Phosphoric Anhydride and Alcohol Figure 3: Chromatrographic Apparatus for the Determination of Total Nonionics by Ion Exchange Chart 1: Typical pH Curves in the Acid Value Titration of Phosphate Esters