Control of reactivity of novolac resins: the use of 3,4-dihydro-2H-pyran as a labile protecting group

The control of the reactivity of novolac resins towards common crosslinkers through the use of 3,4-dihydro-2H-pyran as a protecting group is reported. This thermally labile protecting group is shown to be effective for the control of the cure of the novolac resin system through the use of models and on the resins themselves. The option of controlling the temperature of cure of the resins through the manipulation of the pH of the reaction mixture is also reported. The control of the cure was measured by differential scanning calorimetry (DSC). The use of the protecting group as a means to manipulate the structure of the cured resins is discussed.