Malachite green leuco derivatives as photobase generators for initiating crosslinking and polymerization

摘要

We investigated the pH-changing profile induced by UV irradiation of malachite green leuco derivatives (MG-Xs) and performed polymerization and crosslinking reactions initiated by irradiated MG-Xs. A substituent (X) is covalently linked to the central carbon atom of malachite green, abbreviated as MG-OH or MG-OCH3. MG-Xs undergo photoionization to afford malachite green cations and anions (X-), which act as photobase generators. We found that MG-OCH3 was as effective as MG-OH for photoionization and photo-induced pH jumping. Anionic photo-polymerization of methyl methacrylate was accomplished via irradiation of MG-Xs. Irradiation of MG-Xs triggered the base-promoted crosslinking reaction between pentaerythritol tetra(3-mercaptopropionate) and hexamethylene diisocyanate.