Condensation polymerization of pyrogallol and benzaldehyde

Abstract

AbstractNovolac‐type polycondensation of benzaldehyde (B) and pyrogallol (P) has been carried out at 60°C, 75°C and 90°C and at B/P mole ratios of 1.5 and 3.0 using phosphoric acid as catalyst. The reaction follows a 2nd order rate law. By using GC consumption data of benzaldehyde and pyrogallol, kinetic parameters such as the overall rate constants, activation energies (Ea) and logA values are investigated. The activation energies for 1.5 and 3.0 B/P mole ratios are found as 62.3 kJ mol−1 and 56.4 kJ mol−1, respectively. The molecular weights of the resins determined by measuring intrinsic viscosities (25°C, THF) are in the range of 0.03 to 0.07 dL g−1 at various temperatures and B/P mole ratios.