Hydrodynamic Behavior of Epoxy and Phenol-Formaldehyde Oligomers in Solution during Thermal Precondensation

The concentration dependences of the relative viscosity of epoxy-4,4'-isopropylidenediphenol (Epikot 1009, E-05) and phenol-formaldehyde (DFFr) resins in Cellosolve solutions in the concentration range c = 5-60%, as well as the kinetics of thermal precondensation of a mixture of E-05 and DPFr resins in solution at molar ratios N ₁/N ₂ = 0.6-1.5, were studied by the method of capillary viscometry. The cluster structure of the surface of coatings on the metal sheet formed by cross-linked epoxy-phenol polymer in various kinetic stages of precondensation of the mixture of E-05 and DFFr resins in solution was studied by electron microscopy with gold decoration. The optimal concentrations of resins in solution and the precondensation kinetics of oligomer mixtures essential for formulating the compounds were calculated.