Associate Professor Kohsaka states, "The fun part of polymer science is that your results are tangible. You can measure, quantify and even feel the properties of the plastic that you produce!" Associate Professor Yasuhiro Kohsaka of the Research Initiative for Supra-Materials (RISM) and Mai Yamashita (Graduate School of Textile Science and Technology) et al. of Shinshu University built upon a plastic reported by a research group lead by Professor Xiao-Bing Lu of Dalian University of Technology. With the study "Synthesis of Poly(Conjugated Ester)s by Ring-Opening Polymerization of Cyclic Hemiacetal Ester Bearing Acryl Skeleton", Associate Professor Kohsaka and his colleagues developed a new polyester, enabling simple and inexpensive production. The research demonstrated that this plastic, prepared by 2,6-dimethyl-5-methylene-1,3-dioxan-4-one (abbreviation: DMDO), reacts with chemical substances and decomposes. These results are anticipated to lead to a possible solution of the plastic waste problem. The research paper was published as an invited paper in European Polymer Journal (Elsevier; Switzerland) on August 25, 2019.
The polymerization reaction in the study was performed by adding alcohol as a reaction initiator to DMDO and diphenyl phosphate as a catalyst. According to the theory, DMDO should be incorporated into the polymer skeleton as it is, but it was found that a structure partially missing from DMDO is incorporated into the polymer skeleton. The raw material is DMDO, but the product has the same chemical structure as the polymer polymerized by α-methylene-β-butyrolactone, MβBL. DMDO contains useless chemical structures that cannot be incorporated into polymers, but it can be synthesized from existing basic chemicals at room temperature and pressure, and can be stored stably.
In other words, productivity and storage are overwhelmingly superior to MβBL. Therefore, it is viewed as a possible alternative raw material for MβBL. Research is being continued to add functions such as heat resistance, water repellency, and shape memory to degradable plastics.
