Recently, the research team led by Professors Shen Yong and Li Zhibo from Qingdao University of Science and Technology has achieved significant progress in the design and synthesis of biodegradable and closed-loop recyclable polymer materials, providing a new approach for plastic recycling.

Traditional plastics are non-biodegradable under natural conditions, leading to severe environmental pollution. The development of recyclable and biodegradable aliphatic polyester materials is regarded as one of the effective solutions to plastic pollution. Ring-opening polymerization of cyclic lactones is an important method for preparing aliphatic polyester materials. However, existing catalyst systems face challenges such as low activity, high toxicity and poor controllability.

To address the above issues, the research team developed an organoaluminum catalyst and successfully realized the chemoselective ring-opening polymerization of α-methylene-δ-valerolactone. This catalyst can be prepared in one step from commercially available alkylaluminum and antioxidants without the need for purification. Using this catalyst, the research team achieved living/controlled ring-opening polymerization of various cyclic monomers, thereby preparing high-molecular-weight polyesters. In this process, the catalyst exhibited excellent proton tolerance; even with the addition of 100 equivalents of alcohol, it could still produce polyester polyols with well-controlled molecular weights and end groups.