Scientists at the Tokyo Institute of Technology took for a first time what they call “a direct real-space approach to adopt macroscopic manufacturing laws with no process complexity,” which could be an energy- and cost-efficient solution that would all but replace the traditional polymer-making methods.
Harnessing the Power of Light
Polymers have long since piqued the interest of polymer scientists, especially when it comes to questions about photopolymerization. Polymerization is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional network structures.
Although this approach has become prevalent in most of industrial applications, the researchers have identified that how light is delivered can significantly influence its efficiency as well as the quality of polymers produced.
A group of researchers, led by Professor Atsushi Shishido from the Tokyo Institute of Technology have a different idea for facing this challenge. Instead of just shining UV light all over the solution, they rotated a slowly moving slit for more dramatic lighting. This simple and elegant solution had a striking impact on the photopolymerization process by producing higher-molecular-weight polymers in much shorter exposure time.
The Secrets of Molecular Flow
The deep understanding of the mechanisms at play during photopolymerization is what allows the researchers to uncover these groundbreaking results.
Photoinitiator compound Irgacure 651 undergoes fragmentation upon UV exposure to form reactive free radicals. The radicals bind with monomers, the tiny units in polymers, and ultimately they combine to build longer chains.
Yet the team’s pioneering work in lighting brought an added dimension to this. The UV-light slit that moved then allowed for a stream of molecules to form within the solution with some of the polymer chains forming and diffusing into the non-irradiated regions, before restarting its evolvement. It enabled them to keep expanding when fresh radicals came.
As the non-degraded chains were irradiated to a higher dose, radicals and monomers also diffused with the radicals being fed into the unirradiated parts of those chains and monomers to radiated regions. The consequence of this mutual diffusion was a greatly reduced relative radical: monomer concentration within the irradiated area, minimizing its propensity for termination reactions so that the polymer radicals were given more opportunities to grow to long lengths.
Conclusion
Japan´s Tokyo Institute of Technology reported the findings that could revolutionize the way polymers are made. Utilising dynamic UV lighting, their method would be a simple yet impactful upgrade for photopolymerization as we know it.
This novel method will not only eliminate the energy expense of polymer synthesis but also make higher-performance materials more accessible. As shown by the researchers, their method takes advantage of more than just a monomer and to be applicable to many commodity polymers.
This amazing insight gives hope for an even more sustainable perspective in the production of polymers, and time will show the specific implications this has for some industries and specific applications.
