Near‐infrared light for polymer re‐shaping and re‐processing applications

The shaping and reprocessing of polymers are usually associated with strong energetic costs, strongly limiting their practical usage. In this paper, a new approach is proposed based on a NIR activation of the material in presence of a NIR heater for a highly efficient process upon ecofriendly NIR light emitting diodes irradiation. Markedly, due to this light-triggered process, a spatial control of the shaping/reprocessing behavior can be obtained i.e. only the needed parts are irradiated preventing a heating of all the sample. In this work, different thermoplastics are reshaped or reprocessed due to NIR activation in presence of an organic NIR dye used as heater. As other examples of photothermal treatment upon NIR light, the ondemand dehydration of polyethylene glycol (PEG)-based hydrogels are also provided. All the processes are followed in real time by thermal imaging camera.