Formaldehyde resins. 93. Reaction rate of polynuclear p‐cresol‐formaldehyde‐condensate with formaldehyde in acidic media

The linear poly nuclear p‐cresol‐formaldehyde condensates up to octabodyll were syntHesized, and the rates of their reaction with formaldehyde in ca. 80% dioxane in the presence of perchloric acid were measured. The reaction rates of the one to four nuclear condensates (H1H ∼ H4H) were approximately double of those of higher nuclear condensates (H5H ∼ H8H). The abrupt decrease of the rate of tetrabody(H4H) to the pentabody (H5H) was explained by two considerations: The first is the rolling up form of the higher molecular condensate where the one end (i.e. the reactive site) is hidden by the molecule itself and the second is the formation of hydrogen bonds between all the hydroxyl groups to decrease the reactivity of the aromatic substitution with a methylol cation.