Formation of poly(ethylene phosphates) in polycondensation of H3PO4 with ethylene glycol. Kinetic and mechanistic study

Abstract Conditions of synthesis of poly(ethylene phosphates) in reaction of H 3 PO 4 with HOCH 2 CH 2 OH (EG), the actual path of polycondensation, and structure of the obtained polymers (mostly oligomers) and kinetics of reaction are described. Preliminary kinetic information, based on the comparison of the MALDI‐TOF‐ms and 31 P{ 1 H} NMR spectra as a function of conversion is given as well. Because of the dealkylation process fragments derived from di‐ and triethylene glycols are also present in the repeating units. Structures of the end groups (CH 2 CH 2 OH or OP(O)(OH) 2 ) depend on the starting ratio of [EG] 0 /[H 3 PO 4 ] 0 , although even at the excess of EG the acidic end groups prevail because of the dealkylation process. In MALDI‐TOF‐ms products with P n equal up to 21 have been observed. The average polymerization degrees ( P n ) are lower and have been calculated from the proportion of the end groups. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 830–843, 2008