Phosphorylated phenolic resins
Polimery 2001, No 7-8, 511
SummaryPhosphorylated phenol-formaldehyde (PP) resins were synthesized by melt polycondensation of monophenyl phosphate and formaidehyde (added as trioxane). The structure and the degree of polycondensation of the PP resins were examined by lH, 13C and 31P NMR spectroscopy and by FAB mass spectrometry. Upon esterification. the reactivity of the phenolic ring fell, a fact interpreted in terms of the correlation between the reactivity of phenols toward formaldehyde and the 13C NMR spectral data. The ionic conductivity of aqueous solutions of PP resins was measured and the resistance to hydrolysis (followed by 31P NMR) of soluble non-crosslinked PP resins (degree of polycondensation (DP), 3-7) was examined. The PP resins became crosslinked with forrnaldehyde at room tcmperature in the presence of sulfuric acid. Curing conditions were found to affect the crosslinking density (expressed by equilibrium swelling ratio); the total ion-exchange capacities of the crosslinked products were 8.6-8.96 meq/g (Table 2).