Spatiotemporal Irradiation-Induced Molecular Flow Enables Distinct Photopolymerization

The effects of external force on polymers have been actively studied for a long time. Initially considered a primary factor leading to polymer degradation, it has recently been re-evaluated as crucial for imparting advanced functionalities to polymers. However, the effect of mechanical stimuli deliberately applied to the growing polymers is still unknown. Recently, we developed a novel photopolymerization process using spatiotemporal lighting, which causes molecular flow during the photopolymerization. In this study, we report efficient polymerization behavior under photoinduced molecular flow fields. Photopolymerization with scanning UV light exhibited higher-molecular-weight polymers, with a reduction of 90% of exposure dose compared to photopolymerization with static uniform light. The efficient polymerization behavior is attributed to the spatially reduced radical concentration due to the photoinduced molecular flow. Our proposed approach holds promise for an innovative polymer synthesis process.