New Dye/Dendrimer Photoinitiating Systems Operating under Visible Radiation: Eco‐Friendly Synthesis of Highly Viscous Polymers

A series of new eco-friendly photoinitiating systems (PIs) based on several water-soluble xanthenic dye/PAMAM dendrimer formulations are tested by polymerizing a typical vinyl monomer such as acrylamide. After irradiation with visible LEDs, solutions of viscosity up to 15-fold higher than those with PIs based on low molecular weight amines are obtained. A correlation between solution viscosity and dendrimer structure is also observed. Polymers with ultra-high molecular weights up to around 10(7) are estimated from viscosimetric assays. In addition, very fast reactions are observed under direct solar radiation and the properties of the thus obtained polymers are similar to those synthesized with LEDs. The present findings are promissory for future research and technological applications of the PIs evaluated.