Boosting Highly Ordered Porosity in Lanthanum Metal-Organic Frameworks for Ring-Opening Polymerization of γ-Butyrolactone

gamma-butyrolactone (gamma-BL), serving as the monomer of biocompatible and recyclable poly(gamma-butyrolactone) plastic, faces a giant challenge in ring-opening polymerization (ROP) due to its low strain energy. The ROP of gamma-BL is generally achieved under harsh conditions (e.g., high-pressure or gas-protected atmosphere) and is mostly based on homogeneous systems. Here, we synthesize a series of lanthanum metal-organic framework-based porous nanospheres and successfully apply them as heterogeneous catalysts in efficient ROP of gamma-BL under mild conditions. Specifically, NNU-mIM-3 presents a yield of 24.6% with low polydispersity distribution centered at 3.6 kDa and the obtained P gamma BL can be completely and quantitatively recycled into monomers by simple heat treatment. Besides, the ROP catalysis systems have been intensively explored with various imine-based additives, proven to exhibit largely improved performance with P gamma BL yield of similar to 50% and Mw of similar to 8 kDa. This work paves a new way to explore novel heterogeneous catalysts in producing biocompatible and degradable plastics.

Automated summary

A series of lanthanum metal-organic framework-based porous nanospheres have been synthesized and applied as heterogeneous catalysts for efficient ring-opening polymerization (ROP) of gamma-butyrolactone under mild conditions, showing promising results in terms of yield and recyclability. The use of imine-based additives has further improved the performance of the ROP catalysis systems, paving the way for the production of biocompatible and degradable plastics.